Patent ID: 9676774
Date: 2017-06-13
CPC Classifications: A61K,A61P,C07D

Claim:
1. A process for preparing 1,4-dihydro-7-[(3S,4S)-3-methoxy-4-methylamino-1-pyrrolidinyl]-4-oxo-1-(2-thiazolyl)-1,8-naphthyridine-3-carboxylate hydrate comprising a) contacting ethyl 1,4-dihydro-7-[(3S,4S)-3-methoxy-4-methylamino-1-pyrrolidinyl]-4-oxo-1-(2-thiazolyl)-1,8-naphthyridine-3-carboxylate with aqueous sodium hydroxide and ethanol to obtain a suspension, b) adjusting pH of the suspension to 7.5 with acetic acid, c) heating the suspension of step b to 60° C. for about two hours, d) cooling to obtain a solid, e) washing the solid with water and ethanol to obtain the 1,4-dihydro-7-[(3S,4S)-3-methoxy-4-methylamino-1-pyrrolidinyl]-4-oxo-1-(2-thiazolyl)-1,8-naphthyridine-3-carboxylate hydrate, wherein the hydrate exhibits an X-ray powder diffraction pattern comprising a peak at approximately 8.2 degrees 2θ.