Process for the preparation of clindamycin phosphate

A process for the preparation of a compound having the formula:

• ##STR7## wherein X is hydrogen, loweralkyl, halo, loweralkoxy, nitro, --CF.sub.3 or phenyl, said process comprising:
• treating protected clindamycin hydrochloride with phosphorous oxychloride in the presence of a suitable solvent to obtain a reaction mixture;
• adding benzyl alcohol, unsubstituted or substituted with loweralkyl, halo, loweralkoxy, nitro, --CF.sub.3 or phenyl to the reaction mixture, provided that said benzyl alcohol is unsubstituted when X is hydrogen and when substituted, the substituent is the same as X;
• and subsequently adding water to the reaction mixture to complete the reaction.

A process for the preparation of clindamycin phosphate, said process comprising:

• treating protected clindamycin hydrochloride with phosphorous oxychloride in a suitable solvent to obtain a reaction mixture;
• adding benzyl alcohol to the reaction mixture and subsequently adding water to complete the reaction and thereby obtaining protected clindamycin benzylate, hydrochloride;
• heating the protected clindamycin benzylate hydrochloride in the presence of an acid to obtain deprotected clindamycin hydrochloride;
• isolating the deprotected clindamycin benzylate hydrochloride;
• treating the deprotected clindamycin benzylate hydrochloride with a suitable base to obtain clindamycin benzylate free base;
• isolating the clindamycin benzylate free base;
• and
• treating the clindamycin free base with hydrogen gas in the presence of Pd/C catalyst in a suitable solvent to thereby obtain clindamycin phosphate.