反应详情

(a′) 1-benzyl-4-cyano-4-phenylpiperidine, prepared in situ via neutralization of its hydrochloride, is treated with 94-96% sulfuric acid and acetic acid in toluene at 80-100° C. and the 1-benzyl-4-phenyl-4-piperidinecarboxamide thus obtained is treated with bromine in the presence of sodium methoxide; and then