Rapid preparation of 4-bromomethyl-biphenyl derivatives from 4-methyl compounds, using N-bromo-imide or -amide in carboxylic acid ester solvent, used as pharmaceutical intermediates

摘要

The preparation of 2'-substituted 4-bromomethyl-biphenyl derivatives (I) from 2'-substituted 4-methyl-biphenyl derivatives (II) is effected by bromination using N-bromo-imides or -amides in an organic carboxylic acid ester solvent. The preparation of 2'-substituted 4-bromomethyl-biphenyl derivatives of formula (I) from 2'-substituted 4-methyl-biphenyl derivatives of formula (II) is effected by bromination using N-bromo-imides or -amides in an organic carboxylic acid ester solvent. R = CN, COOR1, CONR1R2, C(OR3)=NR4 or 5-tetrazolyl (optionally substituted by benzyl, COOCH3, COOCH2CH3, 9-fluorenylmethoxycarbonyl, COOCH2CCl3, COOCH2-phenyl, COO-t.butyl, COOCH2CH=CH2, COCCl3, COCF3 or triphenylmethyl); R1, R2 = H or 1-6C (preferably 1-4C) alkyl; R3 + R4 = 2-3C alkylene bridge (optionally substituted by 1-4 1-3C alkyl, n-butyl, isobutyl, t.butyl, phenyl or naphthyl).