CA1204436A - Crystalline cephalosporin hydrochloride monohydrate - Google Patents

Abstract

Abstract 7-(D-2-Naphthylglycylamido)-3-methyl-3-cephem-4-carboxylic acid hydrochloride monohydrate is a stable crystal form of a potent orally active gram positive antibiotic.

Description

~14436 CRYSTALLINE CEPHALOSPORIN
HYDROCHLORIDE MINDWRITE

Background of the Invention 7~(D-2-Naphthylglycylamido)-3-methyl-3-cephem-~-c~rbo~ylic acid recently has been discovered to be z potent orally active antibiotic, displaying favorable pharmacokinetics and excellent gram positive activity.
The compound is synthesized by reactions 7-amino-3-methyl-3-cephem-4-carboxylic acid (7-ADCA) with an N-protected 2-naphthylglycine assaulting agent, followed by removal of the protecting group. The only crystalline form of the compound heretofore known is trio tetrahydrat~.
I on object of this injection is Jo provide a new compound that is a stable crystalline form of 7-(~-2-naphthylglycylamido)-3-methyl-3-ce~hem-d-caen-bullock acid.

Summary of the Invention This invention provides a crystalline come position of matter which is 7-(D-2-naphthylglycyi~mi~o)-3-methyl-3-cephem-4-carboxylic acid hydrochloride moo-hydrate. The crystals are large, dense and stable, and readily lend themselves Jo milling Audi grinding for adapt station to pharmaceutical formulation, particularly it solid dyes forms such as filled capsules and the like.
The hydrochloride MindWrite of this in~entlon is pro-pared by crystal I 2-na~thylglycylamido3 I
methyl-3-cephem-4-r~rboxyl-c acid from an aq~ecus hydra-caloric acid medium.

YO-YO

~2~4~36 retailed Description of the Invention The crystalline compound provided by this in-mention has the following unique x-ray powder diffraction properties when measured with a 114.6 mm Debye-Scherrer camera containing a nickel filtered copper radiation of AYE:

Spacing, d: Relative intensities, I/I

15.64 1.00 7.90 .57 6.61 . 24 6~22 .05 5.74 .24 5.54 .12 4.75 .10 4.47 .14 4.23 .19 4 10 .17 3 go .71 3.85 . 12 3.71 .33 3.49 .07 3.35 .12 3.27 . 14 3.15 .10 3.08 .07 3~03 .07

2~93 ~10 2~78 ~10 2 ~69 ~12 2.61 owe b 2~53 ~10 2~47 ~10 I 37 .10 2.30 .02 2~24 02 2.17 .05 ~Z~3~

The compound provided by this invention can be prepared by reacting 7-(D-2-naphthylglycylamido~-3-methyl-3-cephem-4-carboxylic acid, generally as a salivate or as the crystalline tetrahydrate, with hydrochloric S acid in water or a solution of water and an organic sol-vent such as acetone or acetonitrile. Sufficient hydra caloric acid is employed to maintain the pi of the soul-lion below about 2.0, generally about 0.1 to about 0.8.
The reaction normally is substantially complete after about one to about three hours when carried out at a temperature of about 0 to about 50C. The precipitate that forms is the hydrochloride MindWrite of this in-mention and is readily isolated by standard means.
The compound of this invention alternatively can be prepared by isolating the product of acylation of 7-amino-3-methyl-3-cephem-4-carbo~ylic acid (7-ADCA) from a solvent containing aqueous hydrochloric acid.
For example, 7-ADCA, typically as a silylated derivative, can be assaulted with an N-protected D-2-naphthylglycine acid halide or mixed android. The acylation generally is carried out in an organic solvent such as acetonitrile.
Once the acylation is complete, the protecting groups can be removed by standard procedures and the solution of 7-(D-2-naphthylglycylamido)-3-methyl-3-cephem-4-caen-boxlike acid can be diluted with water so that it con-twins about 10 to 50% by volume of water, and the pi of the solution can be adjusted to about pi 0.1 to about 0.8 by addition of hydrochloric acid. The crystalline product that forms is 7-(D-2-naphthylglycylamido)-3-~04~36 methyl-3-cephem 4-carboxylic acid hydrochloride moo-hydrate.
The preparation of the compound of this invert.-lion is more fully described in the following detailed examples.

Preparation 1 Preparation of D,L-2-naphthylglycine (also 1 a named ~-amino-a-(2-naphthyl)acetic acid A solution of 15.6 ~0.1 m) of 2~naphthaldehyde in 700 ml of 50% ethanol-water containing 14.7 g (0.3 m) of sodium cyanide end 38.4 g (Owe m) of ammonium carbon-ate was heaved at 50C for twenty hours. The reaction mixture was cooled and concentrated to about 4G0 ml by evaporation under reduced pressure, and then the soul-lion was made acidic Jo pi 2.0 by the addition of gone.
hydrochloric acid. The solid precipitate that formed was collected by filtration, washed with dilute hero caloric acid, and dried to afford 22.1 g of 4-(2-naphthyl)-2,4-imidazolidindlone.
A solution of 5.0 g (22 my) of the 4-(2-naphthyl)-2,4-imidazolidindione in 100 ml of 16% (v/v) aqueous sodium hydroxide was heated at reflex for two and one-half hours. The reaction mixture was then filtered, cooled, and washed with ethyl acetate. The aqueous solution was next diluted with ON hydrochloric acid to pi 5.1 and filtered to provide D,L-2-naphthyi-Jo 3 2~g36 Gleason. The reaction was repeated several times to produce larger quantities of the product.
A 10.0 g sample of D,L-2-naphthylglycine was purified by dissolving it in 125 ml of methanol contain-in 3.9 ml of acutely chloride. The reaction mixtures filtered and the filtrate containing D,L-2-naphthyl~
Gleason hydrochloride was diluted with 5 ml of aniline.
The precipitated product was collected by filtration and dried to give 7.0 g of D,L-2-naphthylglycine. mop.
219-221C.

Preparation 2 Resolution of 2-naphthylglycine I A mixture of D and L 2-naphthylslycine (from Preparation 1) was reacted with di-tert.-butyl carbonate and sodium hydroxide to provide D,L-N-tert.-butoxycar-bonyl-2-naphthylglycine. The t.Boc naphthylglycine was reacted with optically pure ~-aminoethylbenzene in the presence of N,NI-dicyclohexylcarbodiimide to provide No phenylethyl)-~-tert.-butoxycarbonylamino-a-(2-naphthyl)acetamide. Separation of the diastereomers my chromatography over silica gel afforded, following acid hydrolysis with ON hydrochloric acid, D-2-naphthylglycine (OR -190 + 3) and L-2-naphthylglycine (OR = ~190 + 3).

I 49~3~

Preparation 3 Preparation of D-N-tert.-butoxycarbonyl-2-naphthylglycine To a stirred solution of 10 g (50 my of D-2-naphthylglycine (from Preparation 2) in 100 ml of lo sodium hydroxide were added 50 ml of tetrahydrofuran followed by 30 g (140 my) of di-tert.-butyl carbonate.
The reaction mixture was stirred at 24C for four hours.
The product was isolated by first washing the reaction mixture three times with 50 ml portions of deathly ether, and then the mixture was made acidic to pi 2.0 my the addition of gone. hydrochloric acid. The aqueous acid mixture was extracted several times with ethyl acetate, and the extracts were combined, washed with water, dried and the solvent was removed by evaporation under reduced pressure to provide 12.8 g (85% yield) of ~-N-tert.-~utoxycarbonyl-2-naphthylglycine.
. .
NOR (DMSOd~ 2.5 (s, OH); 6.85 (s, lo); 7.28-7.9 (m, OH

Preparation 4 7-(D-2-Naphthylglycylamido)-3 methyl-3-cephem-4-carboxylic acid trifluoroacetate salt To a stirred suspension of 1.0 g (4.7 my) of 7-amino-3-methyl-3-cephem-4-carboxylic acid (7-ADCA) in 25 ml of acetonitrile were added in one portion 3.7 ml (14.0 my) of bis(tximethylsilyl)trifluoroacetamide. The -SKYE

reaction mixture was stirred at room temperature until all solids had dissolved, thus indicating complete for-motion of the trimethylsilyl ester of 7-ADCA
In a separate flask a solution of }.35 g (4.5 S my) of D-N-tert.-butoxycar~onyl-2-naphthylglycine (from Preparation 3) in 20 ml of acetonitrile containing 1.1 g ~4.5 my) of N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquino-line (EEDQ) was stirred at room temperature for fifteen minutes. This solution was then added in one portion to the cold (0C) acetonitrile solution containing the in-methylsilyl ester of 7-ADCA from above. The reaction mixture was stirred for one hour at oat, and then warmed lo room temperature. The solvent was removed by evapo-ration under reduced pressure to give an oil, and the oil was dissolved in ethyl acetate, washed two times with lo hydrochloric acid, dried, and the solvent was removed by evaporation to provide 7-(~-N-tert.-butoxy-carbonyl-2naph~hylglycylamido~-3-methyl-3-cephem--4-carboxylic acid as a foam.
The N-protected naphthylglycyl cephalosporin thus produced was dissolved in 5 ml of trifluoroacetic acid, and then the trifluoroacetic acid was removed by evaporation under reduced pressure to provide, following precipitation from deathly ether, 5.7 g of 7-(D~2-naphthylglycylamido)-3-methyl-3-cephem-4-carboxylito acid trifluoroacetate salt.

12~443~

X-619~ -8-Preparation 5 7-(D-2-Naphthylglycylamido)-3-methyl-3-cephem-4-car~oxylic acid tetrahydrate S A mixture of 5.7 y of the trifluoroacetic acid addition salt from Preparation 4 in 55 of 10% (v/v) water and acetonitrile was warmed to about 50C and then filtered to remove the undissolved solids. The filtrate was diluted with 1.8 molar ammonium hydroxide to pi 4.5.
The precipitate that formed was collected my filtration and dried to give 3.15 g (72% yield) of crystalline ED
2-naphthylglycylamido)-3-methyl-3~cephem-4-carboxyyolk acid tetrahydrate.

Preparation 6 The procedure of Preparation 4 was repeated using 5.0 of optically active D-N-tert.-butoxycarbonyl~2-naphthylglycine and 5.6 g of 7-ADCA to provide, follow-in removal of the protecting groups, 6.8 g I yield of D-7-(2-naphthylgIycylamido)-3-methyl-3-cephem-4-carboxylic acid trifluoroacetic acid salt. The salt thus formed was dissolved in 90 ml of acetonitrile and 10 ml of water. The pi of the solution was adjusted to I by addition of triethylamine, and the reaction mix-lure was stirred at 25C for twenty minutes. The mix-lure was filtered and the filtrate was concentrated to dryness and the product was crystallized from water to give 2.9 g of 7-(D-2-naphthylglycylamido)-3-methyl-3-cephem-4-carboxylic acid tetrahydrate.
analysis gala. for C20H19N304S EYE
Theory: C, 51.16; H, 5.80; N, 8.95i S, 6.93;
Found: C, 52.52; H, 5.47; N, 8.73; S, 6.83.
NOR (DMSOd6): ô 1.9 (s, OH); ô 4.8 (s, I 4.9 (dud, 5.6 lid, lo); 7.49-7.99 (m, UP
Preparation 7 To a cold (-20 to ~30C) stirred suspension of 51.0 g of DUN methoxycarbonyl)-2-propenyl]-2-naph-thylglycine sodium salt, prepared by reacting methyl acetoacetate with D-2-naphthylglycine, in aye ml of acetonitrile containing 250 ml of N,N-dimethylformamide were added sequentially 0.44 ml of methanesulfonic acid, 0.45 ml of N,~-dimethylbenzylamine and 12.35 ml of methyl I chloro~ormate. The reaction mixture was stirred for two hours at -20 to -30C following the addition. The react lion mixture was diluted by addition of a cold (0C) solution of 34.24 g 7-amino-3-methyl-3-cephem-4-car-boxlike acid in 230 ml of acetonitrile containing 59.4 ml of N-methyl monotrimethylsilyl trifluoroacetamide. The reaction mixture was stirred for two hours at -20C to -30C and then warmed to 0C. The reaction mixture was acidified by addition of 160 ml of lo hydrochloric acid, and the acidic mixture was stirred while 17.85 g of semi-carbazide hydrochloride were added in one portion. The ~4~36 pi of the reaction mixture was adjusted to 3.0 and main-twined by addition of triethylamin~. After the mixture was warmed to 25~C it was filtered through "Hyflo Super Cot"*
filter aid. The filtrate was diluted by addition of triethyl-amine to pi 6.2 and cooled to 0C for fortify minutes and then filtered. The filter cake was washed four times with 50 ml portions of acetonitrile and dried at 35C for seven hours under reduced pressure to provide 66.8 g of 7-~D-2-naphthylglycylamido)-3-methyl-3-cephem-4-carboxylic acid N,N-dimethylformamide MindWrite.
Yield 86%. Karl Fischer Assay: 4.69%.
NOR (TEA): signals at ~2.1~S,3~), 3.2(S,3~, aback),

3.4(S,3~), 5.2(d,1~), 5.8(dd,1H), 5.8(S,1~), 7.3-8.2(m,7~), 8.3(5,1~).
Example 1 7-(D-2~Naphthylglycylamido)~3-methyl-3-ce~hem-

4 carboxylic acid hydrochloride MindWrite To a stirred solution of 200 ml of water con twining 10 ml of 12N hydrochloric acid were added in one portion 20 g of 7-(D-2-naphthylglycylamido)-3-methyl-3-cephem-4 carboxylic acid N,N-dimethylformamide salivate Rome Preparation 7). The reaction mixture was adjusted to pi 0.60 by addition of 12N hydrochloric acid and then stirred at ~5C for forty-five minutes. The precipitated solid was collected by filtration and washed one time with 50 ml of water. The crystalline material was dried at 35-40C for sixteen hours to give 17.59 g (92%) of *Trademark for "Celite"TM brand of diatomaceous (infusorial) earth, specially processed to give a high filtration rate.

7~(D-2-naphthylglycylamido)-3-methyl-3-cephem-4-caen-boxlike acid hydrochloride MindWrite.
Elemental analysis gala for C20H22ClN3O5S
Theory: C, 53.15; 4.91; N, 9.30; S, 7.09; O, 17.70;
Of, 7.85 Found: C, 52.75; I, 4.85; N, 9.85; S, 7.03; O, 17.07;
Of, 7.60.
Karl Fischer Assay Theory 4.29~, Found 4.62%.
Chloride Assay (by titration): Theory 7.85; Found 8.16 and 8.02. IT (KBr): 3040, 2940, 1768, 1707, 1533, 1232 cm W (Tao): Max 225, =100, 000.
Titration (66% N,N-dimethylformamide-water TV 5.5, 7.3.

Example 2 A solution of 5 g (10.6 my of 7-(D-2-napht~.yl-glycylamido)~3-methyl-3-cephem-4-carboxylic acid twitter-hydrate from Preparation 5) in 50 ml of acetone was heated to 40C and then acidified my addition of 1 ml of 12N hydrochloric acid. the mixture was stirred and diluted by addition of S ml of water and ON ammonium hydroxide to pi 3.3. The pi was lowered to 0.20 by the drops addition of 12N hydrochloric acid, and then the reaction mixture was stirred for two hours at 25C. The precipitated solid was collected by filtration, washed twice with 10 ml portions of water, and dried at 25C
under vacuum for two hours to afford 1.929 g ~40.5%
yield) of crystalline 7-(D-2-naphthylglycylamido)-3-methyl-3-cephem-a~cax~o~ylic acid hydrochloride moo=
hydrate.
Chloride analysis: Theory 7.85%; Found 7.~6%.

~2~36 X-61~8 -12-Example 3 To a warm (40C) stirred solution of 1 ml of 12N hydrochloric acid in 25 ml of water and 25 ml of acetone were added in one portion 5 g of 7-(D~2-naphthylglycylamido) 3-methyl-3-cephem-4-carboxylic acid tetrahydrate (from Preparation 5). additional 12N hydra-caloric acid was added to the reaction mixture to adjust the pi to 0.15, and then the mixture was cooled to 25C
and stirred for two hours. The precipitated solid was collected by filtration, washed with three 10 ml port lions of water, and dried for four hours at 25C under vacuum. The product was determined to ye 3.596 g (75%
yield) of 7-(D-2-naphthylglycylamido)-3-methyl-3-cephem-4-car~oxylic acid hydrochloride MindWrite.
Karl Fischer Theory 4.29%. Found 5.95%.
Chloride analysis: Theory 7.85%. Found 8.09%.

Example 4 A solution of 10 g (21.3 my) of 7-(D-2-naph-thylglycylamido~-3-methyl-3-cephem-4-carboxylic acid tetrahydrate in 100 ml of water containing 5 ml of 12N
hydrochloric acid was stirred at 40C while 12N hydra-caloric acid was added drops to pi 0.6. The reaction mixture was cooled to 25C and was stirred at that them-portray for one hour. The crystalline product was got-looted by filtration, washed twice with 20 ml portions of fresh water, and dried for three hours at 25C under reduced pressure. The dried product was identified as , .

~4436 8.16 g ~84.5% yield) of crystalline 7-(D-2-naphthylglycyl-amido)-3-methyl-3 cephem-4^carboxylic acid hydrochloride MindWrite.
Karl Fischer analysis: Theory 4.2g%. Found 5.37%.
Chloride analysis: Theory 7.85%. Found 7.62%.
The compound of this invention is useful as an oral antibiotic, particularly in the treatment of infect lions caused by gram-positive organisms such as S. Ayers, yoga and I. influenza. The compound is also effect live against anaerobic cocci such as Peptostreptococcus i anaerobius and Peptostre~t. intermezzo. The compound is very well absorbed following oral administration, and its favorable pharmacokinetics make it particularly attractive as an oral treatment for upper respiratory infections.
The compound will be administered at a dose of about 0.5 to about 50 mg/kg of animal body weight, and more normally at a dose of about 1 to about 10 mg/kg.
Such amounts will be administered to a human from once to about four times a day for the effective control and prevention of bacterial infections. typical daily adult dose will be from about 200 to about 500 my per day .
The crystal form provided by this invention will be formulated for convenient oral or parenteral administration, and such formulation will contain about 0.1 to about US percent by weight of active ingredient.
The compound will be mixed with typical pharmaceutical carriers arid excipients such as corn starch, sucrose, microcrystalline cellulose, gelatin, and the like. The , Jo ~2~4~36 formulations will be molded into tablets or placed into gelatin capsules, or made into solutions or suspensions for convenient oral administration. The compound can also be formulated as a slow release long term dosage form employing conventional technology.
The crystal form provided by this invention is very stable for prolonged periods of time, yet is very well absorbed following oral administration.

Claims (2)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for preparing 7-(D-2-naphthyl-glycylamido)-3-methyl-3-cephem-4-carboxylic acid hydro-chloride monohydrate which comprises crystallizing 7-(D-2-naphthylglycylamido)-3-methyl-3-cephem-4-car-boxylic acid from an aqueous hydrochloric acid medium.

2. 7-(D-2-naphthylglycylamido)-3-methyl-3-cephem-4-carboxylic acid hydrochloride monohydrate whenever prepared by a process according to claim 1, or by an obvious chemical equivalent thereof.