Patent ID: 7759483
Filing Date: 2010-07-20
Classification: C07D

Abstract:
1. A process for preparing a 3-alkenylcephem compound of formula (2), the process being characterized by adding at least one of organic solvents selected from the group consisting of alcohols, ethers, aliphatic hydrocarbons, alicyclic ketones and aliphatic ketones to a first solution of a 3-alkenylcephem compound of formula (1) in water or in a solvent mixture of water and at least one organic solvent selected from the group consisting of alcohols, aliphatic ketones, esters, amides and nitriles for crystallization to obtain a second solution or suspension of a 3-alkenylcephem compound of the formula (1), and adjusting the second solution or suspension to a pH of 0.5 to 4 wherein R 1 is benzyl or phenoxymethyl, R 2 , R 3 and R 4 are the same or different and are each a hydrogen atom, C 1-10 alkyl, C 4-8 cycloalkyl, or C 1-3 alkyl substituted with aryl where the aryl is optionally substituted with C 1-4 alkyl, or R 2 and R 3 , when taken together, form a group —(CH 2 ) l X m (CH 2 ) n — optionally substituted with C 1-4 alkyl, X is an oxygen atom or group —N(R 5 )—, l is 0 to 3, m is 0 or 1, n is an integer of 2 to 4, and R 5 is a hydrogen atom or C 1-4 alkyl, wherein R 1 is the same as in formula (1)