4'-(BROMOMETHYL)BIPHENYL-2-CARBOXYLIC ACID t-BUTYL ESTER CRYSTAL, METHOD FOR PRODUCING THE SAME AND METHOD FOR ISOLATING THE SAME

摘要

PROBLEM TO BE SOLVED: (1) To provide a new crystal of 4'-bromomethylbiphenyl-2-carboxilic acid t-butyl ester (hereafter referred to as 'bromo-modification') useful as an intermediate for pharmaceutical preparations, (2) to provide a method for producing the bromo- modification crystal of relatively high purity in an industrial scale, (3) to provide a method of isolating the above crystal, and (4) to solve problems caused by hydrogen bromide after completion of the reaction (e.g. yield drop, acid gas generation). SOLUTION: This crystal of 4'-bromomethylbiphenyl-2-carboxylic acid t-butyl ester has an endothermic peak in the range of 108 deg.C to 109 deg.C in the differential scanning calorimetric curve and a purity of >=96%. The 2nd objective method for producing the crystal comprises crystallization and recrystallization of 4'-bromomethylbiphenyl-2- carboxylic acid t-butyl ester under a reduced pressure of preferably 5 kPa-100 kPa in a hydrocarbon-based solvent. The other objective method for isolating the above ester comprises distilling off under reduced pressure the solvent in the reaction liquid obtained after the reaction followed by substitution with a hydrocarbon-based solvent and then making a crystallization in the hydrocarbon-based solvent under reduced pressures.