反应详情

Commercially available N-hydroxy-acetamide (XVI) is reacted with a suitable substituted fluorobenzonitrile (III), in the presence of an organic base such as t-BuOK, t-BuONa or n-BuOK, in an organic solvent such as DMF, DMSO or NMP, at a temperature in the range of about 80° C. to about 120° C., to yield the corresponding amino-benzoisoxazole (XVII). Amino-bezoisoxazole (XVII) is reacted with glyoxylic acid (V), in the presence of a reducing reagent such as NaBH4, NaBH3CN or NaBH(OAc)3, in an organic solvent such as MeOH, EtOH or IPA with catalytic amount of acid such as acetic acid, trifluoroacetic acid or formic acid, at a temperature in the range of 25° C. to about 60° C., to yield the corresponding acid (XVIII).