[0001] This invention relates to novel antibacterial agents and, in particular, to a series
of 11-0-alkanoyl-4"-deoxy-4"-ureido-oleandomycins and their pharmaceutically acceptable
acid addition salts. The invention also relates to key intermediates leading to the
4"-ureido compounds and to other 4"-amino derived antibacterial agents.
[0002] Oleandomycin, its production in fermentation broths and its use as an antibacterial
agent were first described in U.S. Patent 2,757,123. The naturally occurring compound
is known to have the following structure:
The conventionally accepted numbering scheme and stereochemical representation for
oleandomycin and similar compounds is shown at a variety of positions.
[0003] Several synthetic modifications of this compound are known, particularly those in
which from one to three of the free hydroxyl groups found at the 2', 4" and 11-positions
are esterified as acetyl esters. In addition, there are described in U.S. Patent 3,022,219
similar modifications in which the acetyl in the above-mentioned esters is replaced
with another, preferably unbranched lower alkanoyl of three to six carbon atoms.
[0004] The semi-synthetic oleandomycin compounds of this invention are of the formulae:
wherein R is alkanoyl having two or three carbon atoms; R, is hydrogen, pyridylmethyl,
furylmethyl, thenyl, hydroxypyridyl, phenyl, benzyl or substituted phenyl or benzyl
wherein said substituent is methyl, chloro, fluoro, methoxy, amino or trifluoromethyl;
X is methyl, methoxy, fluoro, chloro or trifluoromethyl; R
2 is -N=C=O or -NHCN; and the pharmaceutically acceptable acid addition salts of 1
and 2, and 3 wherein R
2 is -NHCN.
[0005] Preferred antibacterials related to the compounds of formula 1 are those wherein
R is acetyl. Especially preferred species within this group are N-(11-O-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(p-methoxybenzyl)urea,
N-(11-0-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(p-chlorobenzyl)urea; N-(11-0- acetyl-4"-deoxy-4"-oleandomycyl)-N'-(o-chlorobenzyl)urea,
N-(11-0-acetyl-4"-deoxy-4"-oleandomycyl)-N' -(m-methylbenzyl)urea, N-(11-0-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(m-tolyl)urea
and N-(11-0-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(o-methylbenzyl)urea.
[0006] Preferred antibacterials related to the compounds of formula 2 are those wherein
R is acetyl. Especially preferred species within this group are N-(11-0-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(m-methylbenzoyl)urea
and N-(11-0-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(p-methoxybenzoyl)urea.
[0007] Preferred within the compounds of formula 3 are those wherein R is acetyl. Especially
preferred as an intermediate is 11-0-acetyl-4"-deoxy-4"-isocyanato-oleandomycin.
[0008] In accordance with the process according to the invention for synthesising the 11-0-alkanoyl-4"-
deoxy-4"-ureido-oieandomycin antibacterials related to formula 1 the following scheme
is illustrative:
wherein R and R, are as previously defined.
[0009] The appropriate 11-0-alkanoyl-4"-deoxy-4"-isocyanato-oleandomycin is contacted with
the requisite amine in a reaction-inert solvent. Such solvents should appreciably
solubilize the reactants while not reacting to any significant extent with either
the starting reagents or the products formed. Preferred are aprotic, polar solvents
which are immiscible with water. Especially preferred are methylene chloride and chloroform.
[0010] In practice, one mole of the isocyanate is contacted with up to four moles of the
requisite amine. Alternatively, one to two moles of the amine can be employed in conjunction
with the balance of the four moles being a tertiary amine, such as triethylamine or
pyridine.
[0011] Reaction time is not critical and is dependent on reaction temperature, concentration
and inherent reactivity of the starting reagents. When the reactions are conducted
at ice-bath temperatures at the hereinafter mentioned concentrations, the reaction
is essentially complete in 30-60 minutes. The preferred reaction temperature is ice-bath
temperature.
[0012] The reaction, on completion, is worked-up by the addition of additional solvent and
water. The water layer is made strongly basic with an aqueous sodium hydroxide solution
and the water immiscible organic phase separated, dried and evaporated to dryness.
The crude product can, if desired, be further purified by chromatographing on silica
gel, a procedure well known in the art.
[0013] An alternative method according to the invention for synthesising compounds related
to 1 comprises the reaction of the appropriate 11-0-alkanoyl-4"-deoxy-4"-amino-oleandomycin
with the requisite isocyanate as illustrated:
[0014] This alternative method for preparing compounds related to 1 is conducted in a similar
manner to the initial route. The reactants are contacted in the same type of reaction-inert
solvents at ice-bath temperature. It is convenient, in employing this alternative
method, to allow the reaction temperature to warm to room temperature after the reactants
have initially been brought into contact with one another. The reaction at ambient
temperatures is complete in 30-60 minutes.
[0015] The ratio of 4"-amino-oleandomycin to isocyanate is about one to one with as much
as a 10-20% excess of the isocyanate.
[0016] At the completion of the reaction the product is worked-up in the same manner as
previously discussed.
[0017] The antibacterial agents of formula 2 are prepared according to the invention through
the reaction of the appropriate 11-0-alkanoyl-4" -deoxy-4" -amino-oleandomycin and
benzoyl isocyanate as illustrated:
wherein R and X are as previously defined.
[0018] The reaction is conducted in a reaction-inert solvent similar to that employed in
the routes leading to compounds of formula 1.
[0019] In practice one mole of the 11-0-alkanoyl-4"-deoxy-4"-amino-oleandomycin is contacted
with one mole plus as much as a 10-20% excess of the requisite benzoyl isocyanate.
The ambient reaction temperature of 25°C allows for the completion of the reaction
in 30-60 minutes.
[0020] Again, the reaction is worked-up and the product isolated and purified by the same
procedures employed in the process leading to compounds related to 1.
[0021] Those compounds of formula 3 wherein R is as previously defined and R
2 is -N=C=O are useful intermediates leading to compounds of formula 1 through their
reactions with amines as hereinbefore discussed, and are prepared according to the
invention by the following illustrative scheme:
[0022] In practice, one mole of the 4"-amino compound is contacted with one mole of phosgene
plus as much as a 10-20% excess in the presence of three to four moles of a hydrogen
chloride scavenger such as pyridine or triethylamine. The reaction is best carried
out under anhydrous conditions in a chlorinated hydrocarbon solvent such as methylene
chloride or chloroform.
[0023] It is preferred to add the phosgene in one of the aforementioned solvents to a cold
(0°C) solution of the 4"-amino compound and hydrogen chloride scavenger dissolved
in a similar solvent rapidly with stirring. At the indicated reaction temperature
the product is essentially completely formed in 10-20 minutes.
[0024] The product is isolated by removal of the solvent and excess acid scavenger, followed
by redissolution in fresh solvent, washing with water to remove scavenger amine hydrochloride
and removing the solvent in vacuo. No further purification of the intermediate is
necessary.
[0025] Synthesis of the antibacterial compounds of formula 3 wherein R is as previously
indicated and R
2 is -NHCH is carried out according to the invention through the dehydration of the
corresponding 4"- ureido compound of formula 1 (R,=H) as follows:
[0026] Experimentally, one mole of the 4"-ureido compound and four to five moles of a hydrogen
chloride scavenger in one of the aforementioned chlorinated hydrocarbon solvents at
0°C are treated with ten moles of phosgene in a similar solvent.
[0027] When the preferred reaction temperature of 0°C is employed, the reaction is substantially
complete in 10-20 minutes.
[0028] The product can be isolated in the same manner as previously described for compounds
of formula 3 wherein R
2 is -N=C=O.
[0029] The starting 4"-amino compounds used in the synthesis of antibacterial agents of
the present invention are synthesized by oxidation of the natural oleandomycin followed
by a reductive amination of the resultant ketone as hereinafter described. The isocyanates
employed in the processes for preparing compounds of formulae 1 and 2 are either commercially
available or are synthesized according to the procedures as taught by Speziale et
al., J. Org. Chem., 30, 4306 (1965) and Wagner and Zook, "Synthetic Organic Chemistry",
John Wiley and Sons, New York, N.Y., 1956, p. 640.
[0030] In the utilization of the chemotherapeutic activity of those compounds of the present
invention which form salts, it is preferred, of course, to use pharmaceutically acceptable
salts. Although water- insolubility, high toxicity, or lack of crystalline nature
may make some particular salt species unsuitable or less desirable for use as such
in a given pharmaceutical application, the water insoluble or toxic salts can be converted
to the corresponding pharmaceutically acceptable bases by decomposition of the salt
as described above, or alternatively they can be converted to any desired pharmaceutically
acceptable acid addition salt.
[0031] Examples of acids which provide pharmaceutically acceptable anions are hydrochloric,
hydrobromic, hydroiodic, nitric, sulphuric, sulphurous, phosphoric, acetic, lactic,
citric, tartaric, succinic, maleic, gluconic and aspartic acids.
[0032] The novel 4"-deoxy-4"-amino-oleandomycin derivatives described herein exhibit in
vitro activity against a variety of Grampositive microorganisms such as Staphylococcus
aureus and Streptococcus pyogenes and against certain Gram-negative microorganisms
such as those of spherical or ellipsoidal shape (cocci). Their activity is readily
demonstrated by in vitro tests against various microorganisms in a brain-heart infusion
medium by the usual two-fold serial dilution technique. Their in vitro activity renders
them useful for topical application in the form of ointments, creams and the like;
for sterilisation purposes, e.g. sick-room utensils; and as industrial antimicrobials,
for example, in water treatment, slime control, paint and wood preservation.
[0033] For in vitro use, e.g. for topical application, it will often be convenient to compound
the selected product with a pharmaceutically-acceptable carrier such as vegetable
or mineral oil or an emollient cream. Similarly, they may be dissolved or dispersed
in liquid carriers or solvent, such as water, alcohol, glycols or mixtures thereof
or other pharmaceutically-acceptable inert media; that is, media which have no harmful
effect on the active ingredient. For such purposes, it will generally be acceptable
to employ concentrations of active ingredients of from 0.01 percent to 10 percent
by weight based on total composition.
[0034] Additionally, many compounds of this invention are active versus Gram-positive microorganisms
via the oral and/or parenteral routes of administration in animals, including man.
Their in vivo activity is more limited as regards susceptible organisms and is determined
by the usual procedure which comprises infecting mice of substantially uniform weight
with the test organism and subsequently treating them orally or subcutaneously with
the test compound. In practice, the mice, e.g. 10, are given an intraperitoneal inoculation
of suitably diluted cultures containing approximately 1 to 10 times the LD
100 (the lowest concentration of organisms required to produce 100% deaths). Control
tests are simultaneously run in which mice receive inoculum of lower dilutions as
a check on possible variation in virulence of the test organism. The test compound
is administered 0.5 hour post-inoculation, and is repeated 4, 24 and 48 hours later.
Surviving mice are held for four days after the last treatment and the number of survivors
is noted.
[0035] When used in vivo, these novel compounds can be administered orally or parenterally,
e.g., by subcutaneous or intramuscular injection at a dosage of from 5 mg./kg. to
200 mg./kg. of body weight per day. The favoured dosage range is from 25 mg./kg. to
100 mg./kg. of body weight per day and the preferred range from 50 mg./kg. to 75 mg./kg.
of body weight per day. Vehicles suitable for parenteral injection may be either aqueous
such as water, isotonic saline, isotonic dextrose, Ringers' solution, or non-aqueous
such as fatty oils of vegetable origin (cotton seed, peanut oil, corn, sesame), dimethylsulfoxide
and other non-aqueous vehicles which will not interfere with therapeutic efficiency
of the preparation and are non-toxic in the volume of proportion used (glycol, propylene
glycol, sorbitol). Additionally, compositions suitable for extemporaneous preparation
of solutions prior to administration may advantageously be made. Such compositions
may include liquid diluents, for example, propylene glycol, diethyl carbonate, glycerol,
sorbitol, etc.; buffering agents, hyaluronidase, local anaesthetics and inorganic
salts to afford desirable pharmacological properties. These compounds may also be
combined with various pharmaceutically-acceptable inert carriers including solid diluents,
aqueous vehicles, non-toxic organic solvents in the form of capsules, tablets, lozenges,
troches, dry mixes, suspensions, solutions elixirs and parenteral solutions or suspensions.
In general, the compounds are used in various dosage forms at concentration levels
ranging from 0.5 percent to 90 percent by weight of the total composition.
[0036] Thus the invention provides a pharmaceutical composition comprising a compound of
the formula 1 or 2 or 3 wherein R
2 is -NHCN; or a pharmaceutically acceptable acid addition salt thereof, together with
a pharmaceutically acceptable diluent or carrier.
[0037] The following Examples illustrate the invention:-
EXAMPLE 1
11-0-Acetyl-4"-deoxy-4"-isocyanato-oleandomycin
[0038] To a solution of 5.0 g. (6.6 mmoles) of 11-0-acetyl-4"-deoxy-4"-amino-oleandomycin
and 1.65 ml. (20.5 mmoles) of pyridine in 100 ml. of anhydrous methylene chloride
cooled to 0°C is added 18.3 ml. of a 0.41M solution of phosgene in chloroform with
rapid stirring. After 10 min. stirring at 0°C the solvent and excess pyridine are
removed in vacuo leaving the crude product as a yellow foam. The residue is dissolved
in 100 ml. of methylene chloride which is washed (2 x 100 ml.) with water and dried
over sodium sulphate. The solvent is removed under reduced pressure to provide the
desired 4.0g. of the product.
[0039] NMR (8, CDCI
z): 2.09 (3H)s; 2.61 (6H)s; 2.68 (2H)m; and 3.45 (3H)s.
[0040] In a similar manner, starting with 11-O-propionyl-4"-deoxy-4"-amino-oleandomycin,
11-0-propionyi-4"-isocyanato-oieandomycin is prepared.
EXAMPLE 2
11-O-Acetyl-4"-deoxy-4"-ureido-oleandomycin
[0041] To 3.02g. (4.0 mmoles) of 11-0-acetyl-4"-deoxy-4"-isocyanato-oleandomycin in 70 ml.
of tetrahydrofuran at ambient temperatures is added 0.928 ml. of concentrated aqueous
ammonium hydroxide (12 mmoles) over a 10 min. period. The yellow foam, which remains
after the reaction mixture is evaporated to dryness, is chromatographed on a 3.25
x 38 cm. silica gel-acetone packed column. The initial eluting solvent is acetone.
Methanol is gradually added to the eluting solvent until the final elution when it
is 25% by volume.
[0042] The column factions, shown by thin layer chromatography to be pure, are combined
and the solvent removed in vacuo to give 2.30g. of the desired product as an amorphous
solid.
NMR (8, CDCL3): 2.10 (3H)s; 2.36 (6H)s; 2.70 (2H)m;
3.47 (3H)s; and 5.70 (1H)b.
EXAMPLE 3
11-O-Acetyl-4"-deoxy-4"-cyanamido-oleandomycin
[0043] To 570 mg. (0.74 mmoles) of 11-0-acetyl-4"-deoxy-4"-ureido-oleandomycin and 0.5 ml.
(3.6 mmoles) of triethylamine in 25 ml. of anhydrous methylene chloride cooled to
0°C is added 1.80 ml. of a 0.41M solution of phosgene in chloroform (7.4 mmoles).
After 5 min. of stirring in the cold, the reaction is diluted with 100 ml. of methylene
chloride. The resulting solution is washed with water (3 x 100 ml.), dried over sodium
sulphate and concentrated under reduced pressure to afford 400 mg. of the desired
product as an amorphous solid.
NMR (8, CDCI3): 2.10 (3H)s; 2.30 (6H)s; 2.64 (2H)m;
and 3.44 (3H)s.
EXAMPLE 4
N-(11-O-Acetyl-4"-deoxy-4"-oleandomycyl)-N'-benzylurea
[0044] A cold (0°C) solution of 3.0g. (4.11 mmoles) of 11-0-acetyl-4" -deoxy-4" -amino-oleandomycin
and .99 ml. of pyridine in 60 ml. of dry methylene chloride is rapidly stirred while
10.98 mi. of a .41M solution of phosgene in chloroform is added rapidly. After 5 min.
1.8 ml. of benzylamine is added and the stirring continued in the cold for an additional
15 min. The reaction is diluted with 150 ml. of methylene chloride, layered with 150
ml. of water and the pH of the aqueous layer adjusted to 9.5 with aqueous 6N sodium
hydroxide solution. The separated organic layer is washed with water (3 x 150ml) dried
over sodium sulphate and concentrated to an amber foam in vacuo. The residue is chromatographed
on a 3.5 x 37 cm. silica gel-acetone packed column using acetone as the eluate, the
eluent being collected in 5 ml. fractions. 99 5 ml. fractions are collected and discarded.
Fractions 100-119, comprising 5 ml. each, are combined and concentrated to dryness
to give 69 mg. of the desired product. Similarly, fractions 120-195 are combined and
concentrated to dryness to give 451 mg. of the desired product.
NMR (8, CDCI3): 2.08 (3H)s; 2.34 (6H)s; 2.68 (2H)m;
3.4 (3H)s; and 7.34 (5H)s.
EXAMPLE 5
[0045] Starting with the appropriate benzylamine and employing the procedure of Example
4, the following compounds are prepared:
EXAMPLE 6
[0046] The procedure of Example 4 is again repeated, starting with the appropriate reagents,
to give the following analogs:
N - (11 - 0 - propionyl - 4" - deoxy - 4" - oleandomycyl) - N' - benzylurea; N - (11
- 0 - acetyl-4" - deoxy - 4" - oleandomycyl) - N' - (p - methylbenzyl)urea; N - (11
- 0 - propionyl - 4" - deoxy - 4"- oleandomycyl) - N' - (o - methylbenzyl) - urea;
N - (11 -.0 - propionyl - 4" - deoxy - 4" - oleandomycyl) - N' - (p - methylbenzyl)urea;
and N - (11 - 0 - propionyl - 4" - deoxy - 4" - oleandomycyl)-N'-m-methylbenzyl)urea.
EXAMPLE 7
N-(11-0-Acetyl-4" -deoxy-4" -oleandomycyl)-N'-(o-chlorobenzyl)urea
[0047] A .3M solution of phosgene in chloroform (10 mi.) is added rapidly with stirring
to a solution of 2.0 g. (2.7 mmoles) of 11-0-acetyl-4"-deoxy-4"-amino-oleandomycin
and .65 mi. of pyridine in 50 ml. of dry methylene chloride cooled to 0°C in an ice
bath. The solvent is removed under reduced pressure, and the residual yellow foam
dissolved in 50 mi. of dry methylene chloride. The solution is cooled with an ice
bath and treated with 1.08 ml. of o-chlorobenzylamine.
[0048] After 30 min. the reaction solution is washed with water (2 x 100 ml.), the pH being
adjusted to 9.5 with 6N aqueous sodium hydroxide solution during the final washing.
The methylene chloride layer is separated, dried over sodium sulphate and concentrated
in vacuo to give 3.3 g. of the desired product as a yellow foam.
[0049] The product is further purified by chromatographing on a 3.25 x 38 cm., silica gel-acetone
packed column, using acetone as the eluate. Fractions 201-300, comprising 5 ml. each,
are combined and concentrated to dryness to give 1.9 g. of the pure product.
NMR (δ, CDCI3): 2.07 (3H)s; 2.31 (6H)s; 2.66 (2H)m;
3.41 (3H)s; and 7.1-7.59 (4H)m.
[0050] Also prepared by the procedure of Example 7, when the requisite starting materials
are employed, are:
N-(11-0-acetyl-4"-deoxy-4"-oleandomycy)-N'-(p-chlorobenzyl)urea NMR (8, CDCI3): 2.15 (3H)s; 2.31 (6H)s; 2.66 (2H)m; 3.39 (3H)s; and 7.27 (4H)s.
N-(11-O-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(2,4-dichlorbenzyl)urea NMR (8, CDCI3): 2.10 (3H)s; 2.34 (6H)s; 2.70 (2H)m; 3.45 (3H)s; and 7.28-7.60 (3H)m.
N-(11-0-acetyl-4"-deoxy-4" -oleandomycyl)-N'-(3,4-dichlorobenzyl)urea NMR (8, CDCI3): 2.10 (3H)s; 2.35 (6H)s; 2.69 (2H)m; 3.45 (3H)s; and 7.06-7.56 (3H)m.
N-(11-0-acetyl 4"-deoxy-4"-oleandomycyl-N'-(o-fluorobenzyl)urea NMR (8, CDCI3): 2.07 (3H)s; 2.36 (6H)s; 2.71 (2H)m; 3.45 (3H)s; and 6.89-7.65 (4H)m.
EXAMPLE 8
[0051] Employing the procedure of Example 7 and starting with the appropriate reagents,
the following congeners are synthesized;
N-(11-Ò-propionyl-4"-deoxy-4"-oleandomycyl)-N'-(o-chlorobenzyl)urea;
N-(11-O-propionyl-4"-deoxy-4"-oleandomycyl)-N'-(p-chlorobenzyl)urea;
N-(11-O-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(m-chlorobenzyl)urea;
N-(11-0-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(m-fluorobenzyl)-urea;
N-(11-0-propionyl-4" -deoxy-4" -oleandomycyl)-N' -(p-fluorobenzyl)urea;
N-(11-0-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(o-trifluoromethylbenzyl)urea;
N-(11-O-propionyl-4"-deoxy-4"-oleandomycyl)-N'-(p-trifluoromethylbenzyl)urea; and
N-(11-0-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(m-trifluoromethylbenzyl)urea.
EXAMPLE 9
N-(11-0-Acetyl-4"-deoxy-4"-oleandomycyl)-N'-(p-methoxybenzyl)urea
[0052] To a -solution of 2.0 g. (2.7 mmoles) of 11-O-acetyl-4"-deoxy-4"-amino-oleandomycin
and .65 ml. of pyridine in 50 mi. of dry methylene chloride cooked to 0°C is added
rapidly with stirring 10 ml. of a .3M solution of phosgene in chloroform.
[0053] The solvent is removed under vacuum and the residue dissolved in 50 ml. of dry methylene
chloride. After cooling in an ice bath 1.35 mi. of p-methoxybenzylamine is added and
the reaction mixture allowed to stir at ice bath temperatures for one hour. Methylene
chloride (100 ml.) is added to the reaction mixture followed by 100 ml. of water.
The organic layer is separated and washed with fresh water and the pH adjusted to
9.5 with 6N aqueous sodium hydroxide solution. The organic phase is subsequently separated,
dried over sodium sulphate and concentrated to give 2.5 g of a yellow foam.
[0054] The product is further purified by chromatographing on silica gel using acetone as
the elutent. Fractions, which are comprised of 5 ml. each, 221-395 are combined and
concentrated in vacuo to dryness to give 1.4 g. of the product.
NMR (8, CDCI3): 2.08 (3H)s; 2.32 (6H)s; 2.64 (2H)m;
3.37 (3H)s; 3.78 (3H)s; 6.83 (2H)s; and 7.22 (2H)s.
EXAMPLE 10
[0055] The procedure of Example 9 is repeated, starting with the requisite reagents, to
give the following compounds:
N-(11-0-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(o-methoxybenzyl)urea; N-(11-0-acetyl-4"-
deoxy-4"-oleandomycyl)-N'-(m-methoxybenzyl)urea; N-(11-0-propiony)-4"-deoxy-4"-oleandomycyl)-N-(O-methoxybenzyl)urea;
and N-(11-0-propionyl-4"-deoxy-4"-oleandomycyl)-N'-(o-methoxybenzyl)-urea.
EXAMPLE 11
N-(11-0-Acetyl-4"-deoxy-4"-oleandomycyl)-N'-(o-aminobenzyl)urea
[0056] To a well stirred and cooled (0°C) solution of 2.0 g. (2.7 mmoles) of 11-0-acetyl-4"-deoxy-4"-
amino-oleandomycin and .65 ml. of pyridine in 50 ml. of dry methylene chloride is
added rapidly 10 ml. of a 0.3M phosgene chloroform solution.
[0057] The reaction mixture is concentrated under reduced pressure, and the residual yellow
foam dissolved in 50 ml. of dry methylene chloride. The solution is cooled in an ice
bath and is then treated with 2.5 mi. of triethylamine followed immediately by 1.8
g. of o-aminobenzylamine dihydrochloride. After stirring in the cold for one hour,
the reaction is quenched with water (75 ml.) and the pH of the aqueous wash adjusted
to 9.5 with 1N aqueous sodium hydroxide solution. The organic phase is separated,
dried over sodium sulphate and concentrated in vacuo to dryness to give 3.0 g. of
the product as a yellow foam.
[0058] Further purification by chromatographing on a silica gel acetone packed column gives
1.5 g of pure product.
NMR (δ, CDCI3): 2.06 (3H)s; 2.32 (6H)s; 2.65 (2H)m;
3.39 (3H)s; and 6.48-7.43 (4H)m.
EXAMPLE 12
[0059] The procedure of Example 11 is employed, starting with the appropriate reagents,
to give the following compounds:
EXAMPLE 13
N-(11-O-Acetyl-4"-deoxy-4"-oleandomycyl)-N'-(4-pyridylmethyl)urea
[0060] To a well stirred and cooled (0°C) solution of 2.0 g. (2.7 mmoles) of 11-0-acetyl-4"-deoxy-4"-
amino-oleandomycin and .65 ml. of pyridine in 50 ml. of dry methylene chloride is
added rapidly 7.24 ml. of a .41M chloroform solution of phosgene.
[0061] The reaction mixture is concentrated in vacuo to a foam, which is dissolved in 50
ml. of methylene chloride. The solution is subsequently cooled to ice bath temperatures
and treated with .93 ml. of 4-aminomethylpryidine. After one hour of stirring in the
cold the reaction mixture is treated with 100 ml. of methylene chloride and 75 ml.
of water. The water is separated and fresh water mixed with the methylene chloride.
The pH of the aqueous layer is adjusted to 9.5 with 6N aqueous sodium hydroxide solution.
The organic phase is separated, dried over sodium sulphate and concentrated to dryness
to give 2.3 g. of the product as a yellow foam.
[0062] Further purification is effected by chromatographing on a silica gel column using
20% methanol-80% acetone (v:v) as the eluate. In this manner 1.5 g. of pure product
is isolated.
NMR (8. CDCI3): 2.07 (3H)s; 2.33 (6H)s; 2.70 (2H)m;
3.34 (3H)s; 7.29 (2H)s; and 8.54 (2H)s.
[0063] In. a similar manner is prepared N-(11-0-acetyl-4''-deoxy-4"-oleandomycyl)-N'-(2-pyridylmethyl)urea,
starting from 11-O-acetyl-4"-deoxy-4"-amino-oleandomycyl and 2-aminomethylpyridine.
NMR (8, CDCI3); 2.03 (3H)s; 2.31 and (6H)s; 2.67 (2H)m;
3.39 (3H)s; 8.5-8.69 (1H)m and 7.05-7.91 (3H)m.
EXAMPLE 14
N-(11-0-Acetyl-4"-deoxy-4"-oleandomycyl)-N'-(2-furylmethyl)urea
[0064] In a manner similar to the procedure of Example 13, 2.0 g. (2.7 mmoles) of 11-0-acetyl-4"-
deoxy-4"-amino-oleandomycin is converted to 11-0-acetyl-4"-deoxy-4"-isocyanato-oleandomycin,
which on treatment with 870 mg. of furylmethylamine gives, after chromatographing
on silica gel, 1.59 g. of product.
NMR (δ, CDCI3): 2.07 (3H)s; 2.31 (6H)s; 2.67 (2H)m;
3.40 (3H)s; 6.11-6.36 and 7.19-7.41 (3H)m.
[0065] In like manner is prepared N-(11-O-propionyl-4"-deoxy-4"-oleandomycyl)-N'-(2-furylmethyl)-urea
and N-(11-0-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(3-furylmethyl)urea, starting from,
respectively, 11-0-propionyl-4"-deoxy-4"-amino-oleandomycin and 2-furylmethylamine,
and 11-0- acetyl-4"-deoxy-4'iamino-oleandomycin and 3-furylmethylamine.
EXAMPLE 15
[0066] The procedure of Example 13 is repeated, starting with the requisite reagents to
give the following compounds:
EXAMPLE 16
N-(11 -0-Acetyl-4"-deoxy-4"-oleandomycyl)-N'-(3-hydroxy-2-pyridyl)urea
[0067] To 2.03 g. (2.7 mmoles) of 11-0-acetyl-4"-deoxy-4"-isocyanato-oleandomycin in 50
ml. of dry methylene chloride is added 600 mg. (5.4 mmoles) of 2-amino-3-hydroxypyridine,
and the resulting solution stirred for one hour. The reaction mixture is washed with
water and the water layer discarded. Fresh water is layered over the organic phase
and the pH adjusted to 7.5 with 6N-aqueous sodium hydroxide solution. The methylene
chloride layer is separated, dried over sodium sulphate and concentrated under reduced
pressure to give 3.6 g. of a white foam.
[0068] The sample is further purified by chromatographing over silica gel using acetone
eluate. Combined fractions (5 ml. each) 115-770 are concentrated in vacuo to give
800 mg. of pure product.
NMR (8, CDCI3): 2.10 (3H)s; 2.31 (6H)s; 2.68 (2H)m;
3.47 (3H)s; 6.52―6.83 (1 H)m; 7.28-7.5 (1 H)m; and
7.84-8.01 (1H)m.
EXAMPLE' 17
[0069] Starting with the appropriate reagents and employing the procedure of Example 16,
the following compounds are synthesized:
EXAMPLE 18
N-(11-0-Acetyl-4"-deoxy-4"-oleandomycyl)-N'-phenylurea
[0070] A reaction mixture comprising 25 g. (3.4 mmoles) of 11-0-acetyl-4"-deoxy-4"-amino-oleandomycin
and .41 ml. (3.8 mmoles) of phenylisocyanate in 25 ml. of dry methylene chloride at
0°C . is stirred for one hour and warmed to room temperature. The reaction mixture
is treated with 100 ml. of methylene chloride and 100 ml. of water. The pH of the
water layer is adjusted to 9.9 with 1N aqueous sodium hydroxide and the methylene
chloride layer separated, dried over sodium sulphate and concentrated in vacuo to
dryness. The residual foam is chromatographed on silica gel, the fractions (5 ml.
each) being monitored for purity using thin layer chromatography (dimethylformamide/CH
30H 1:3 by volume). Fractions 45-90 are combined and concentrated to give 226 mg. of
a white foam.
NMR (δ, CDCI3): 2.06 (3H)s; 2.31 (6H)s; 2.71 (2H)m;
3.34 (3H)s; and 7.25-7.56 (5H)m.
EXAMPLE 19
N-(11-0-Acetyl-4"-deoxy-4"-oleandomycyl)-N'-(p-chlorophenyl)urea
[0071] Three grams (4.1 mmoles) of 11-0-acetyl-4"-deoxy-4"-amino-oleandomycin in 50 ml.
of dry methylene chloride under a nitrogen atmosphere and cooled to 0°C is treated
with 740 mg. (4.1 mmoles) of p-chlorophenylisocyanate. The reaction mixture is allowed
to warm to room temperature and stirred at ambient temperature for one hour. Methylene
chloride (100 mi.) and water (100 ml) are added to the reaction mixture and the pH
of the water layer adjusted to 9.9 with 1N aqueous sodium hydroxide. The organic phase
is separated, dried over sodium sulphate and concentrated in vacuo to a yellow foam.
[0072] The residual product is further purified by chromatographing on silica gel, the fraction
5 ml. each, being monitored by thin layer chromatography (CHCI
3/CH
30H/NH
40H 9:1:0.1 by volume). Fractions 115-155 are combined and stripped under reduced pressure
to give 716 mg. of the product as a white foam.
NMR (δ, CDCI3): 2.07 (3H)s; 2.34 (6H)s; 2.69 (2H)m;
3.44 (3H)s; and 7.12 and 7.31 (4H).
EXAMPLE 20
[0073] Starting with the appropriate reagents and employing the procedure of Example 19,
the following congeners are prepared:
N-(11-0-acetyl-4 "-deoxy-4 "-oleandomycyl)-N'-(m-tolyl)urea NMR (8, CDCI3): 2.08 (3H)s; 2.35 (6H)s; 2.70 (2H)m; 3.48 (3H)s; 6.78-7.38 (4H)m.
N-(11-0-acetyl-4"-deoxy-4 "-oleandomycyl)-N'-(p-tolyl)urea NMR (δ, CDC13): 2.07 (3H)s; 2.32 (6H) and (3H) broad s; 3.47 (3H)s; and 7.13 and 7.35 (4H)
N-(11-0-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(o-chlorophenyl)urea NMR (δ, CDCI3): 2.10 (3H)s; 2.30 (6H)s; 2.70 (2H)m; 3.5 (3H)s; and 6.8-8.1 (4H)m.
N-(11-0-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(p-methoxyphenyl)urea NMR δ, CDCI3): 2.07 (3H)s; 2.35 (6H)s; 2.67 (2H)m; 47 (3H)s; 3.83 (3H)s; and 6.89 and 7.34 (4H).
EXAMPLE 21
[0074] The procedure of Example 19 is again repeated, starting with the requisite reagents,
to provide the following compounds:
EXAMPLE 22
N-(11 -0-Acetyl-4"-deoxy-4"-oleandomycyl)-N'-(p-methoxybenzoyl)urea
[0075] To a solution of 3.0 g. (4.1 mmoles) of 11-0-acetyl-4"-deoxy-4"-amino-oleandomycin
in 50 ml. of dry methylene chloride at 25°C, is added 660 mg. (4.5 mmoles) of p-methoxybenzoyl
isocyanate. The mixture is stirred at 25°C for 0.5 hours, after which the solvent
is removed under reduced pressure.
[0076] The residual yellow foam is chromatographed over silica gel using acetone as the
eluate. The fractions, which are comprised of 5 ml. each, are monitored with thin
layer chromatography. Those fractions containing the pure product are combined and
concentrated to give 440 mg. of the product as a colourless amorphous solid.
NMR (8, CDCI3): 2.11 (3H)s; 2.32 (6H)s; 2.72 (2H)m;
3.47 (3H)s; 3.92 (3H)s; and 7.02 and 8.01 (4H).
[0077] In a similar manner is prepared:
N-(11-O-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(m-methylbenzoyl)urea NMR (8, CDCI3): 2.08 (3H)s; 2.32 (6H)s; 2.48 (3H)s; 2.71 (2H)m; 3.42 (3H)s; and 7.28-7.84 (4H)m.
and N-(11-0-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(p-chlorobenzoyl)urea NMR (δ; CDCI3): 2.05 (3H)s; 2.27 (6H)s; 2.65 (2H)m; 3.35 (3H)s; and 7.37 and 7.94 (4H).
EXAMPLE 23
[0078] Employing the procedure of Example 22, and starting with the appropriate reagents,
the followinq compounds are synthesised:
N-(11-0-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(p-fluorobenzoyl)urea: N-(11-0-acetyl-4"-deoxy-4"-
oleandomycyl)-N'-(m-trifluoromethylbenzoyl)urea: N-(11-0-propionyl-4"-deoxy-4"-oleandomycyl)-N'-(o-chlorobenzoyl)urea:
N-(11-0-propionyl-4"-deoxy-4"-oleandomycyl)-N'-(o-methylbenzoyl)urea: N-(11-0-propionyl-4"-deoxy-4"-oleandomycyl)-N'-(o-fluorobenzoyl)urea;
N-(11-0-propionyl-4"-deoxy-4"-oleandomycyl)-N'-(m-trifluoromethylbenzoyl)urea; and
N-(11-0-acetyl-4"-deoxy-4"-oleandomycyl)-N'-(p-fluorobenzoyl)urea.
PREPARATION A
4"-Deoxy-4"-amino-oleandomycins
I. 11-0-Acetyl-4"-deoxy-4"-oxo-oleandomycin
a. 11,2'-Di-0-acetyl-4''-deoxy-4"-oxo-oleandomycin
[0079] ' To 4.5 g. ofN-chlorosuccinimide, 50 ml. of benzene and 150 ml. of toluene in a
dry flask fitted with a magnetic stirrer and nitrogen inlet and cooled to -5°C. is
added 3.36 ml. of dimethylsulfide. After stirring at 0°C for 20 min., the contents
are cooled to -25°C and treated with 5.0 g. of 11,2'-di-O-acetyl-oleandomycin in 100
mi. of toluene. Cooling and stirring are continued for 2 hours followed by the addition
of 4.73 ml. of triethylamine. The reaction mixture is stirred at 0°C for 15 min.,
and is subsequently poured into 500 ml. of water. The pH is adjusted to 9.5 with 1N
aqueous sodium hydroxide and the organic layer separated, washed with water and a
brine solution and dried over sodium sulphate. Removal of the solvent in vacuo gives
4.9 g. of the desired product as a foam.
NMR (8, CDCI3): 3.48 (3H)s; 2.61 (2H)m; 2.23 (6H)s
and 2.03 (6H)s.
b. 11-0- Acetyl-4"-deoxy-4"-oxo-oleandomycin
[0080] A solution of 4.0 g. of 11,2'-di-0-acetyl-4"-deoxy-4"-oxo-oleandomycin in 75 ml.
of methanol is stirred at room temperature overnight. The reaction mixture is concentrated
under reduced pressure to give the product as a foam. A diethyl ether solution of
the residue, on treatment with hexane, gives 2.6 g. of the product as a white solid,
m.p. 112-117°C.
NMR (8, CDCI3): 3.43 (3H)s; 2.60 (2H)m; 2.23 (6H)s
and 2.01 (3H)s.
[0081] Similarly, by employing 11,2'-di-0-propionyl-4"-deoxy-4"-oxo-oleandomycin or 11-0-propionyl-2'-0-acetyl-4."-deoxy-4"-oxo-oleandomycin
in the above procedure, 11-0-propionyl-4"-deoxy-4"-oxo- oleandomycin is prepared.
II. 11-0-Acetyl-4"-deoxy-4"-amino-oleandomycin
[0082] To a suspension of 10 g. of 10% palladium-on-charcoal in 100 mi. of methanol is added
21.2 g. of ammonium acetate and the resulting slurry is treated with a solution of
20 g. of 11-0-acety)-4"-deoxy-4"-oxo-oleandomycin in 100 ml. of the same solvent.
The suspension is shaken at room temperature in a hydrogen atmosphere at an initial
pressure of 3515 g-cm-
2 (50 p.s.i.). After 1.5 hours the catalyst is filtered and the filtrate is added with
stirring to a mixture of 1200 ml. of water and 500 ml. of chloroform. The pH is adjusted
from 6.4 to 4.5 and the organic layer is separated. The aqueous layer, after a further
extraction with 500 ml. of chloroform, is treated with 500 mi. of ethyl acetate and
the pH adjusted to 9.5 with 1N sodium hydroxide. The ethyl acetate layer is separated
and the aqueous layer extracted again with ethyl acetate. The ethyl acetate extracts
are combined, dried over sodium sulphate and concentrated to a yellow foam (18.6 g.),
which on crystallisation from diisopropyl ether, provides 6.85 g. of the purified
product, m.p. 157.5-160
0C.
NMR (δ, CDCl3): 3.41 (3H)s; 2.70 (2H)m; 2.36 (6H)s;
and 2.10 (3H)s.
[0083] The other epimer, which exists in the crude foam to the extent of 20-25% is obtained
by gradual concentration and filtration of the mother liquors.
[0084] In a similar manner, starting with 11-0-propionyl-4"-deoxy-4"-oxo-oleandomycin in
the above procedure, gives 11-0-propionyl-4"-deoxy-4"-amino-oleandomycin.