PURPOSE: To obtain the title compound of an intermediate for synthesizing a compound useful as a drug for curing arrhythmia, angina pectoris, etc. in high yield and purity, by submitting an easily and economically obtainable novel anilide derivative as a raw material to ring closure in the presence of an acid.
CONSTITUTION: A novel anilide derivative [e.g., N-(β-methoxyacryloyl)-2,5-dimethoxyanilyl, etc.] shown by the formula I [R1 and R2 are H or alkyl; A is R3 CH=CH-(R3 is alkoxy or halogen), group shown by the formula II (R4 and R5 are alkyl), CH≡C-] undergoes ring closure in the presence of an acid to give a carbostyryl derivative (e.g., 5,8-dimethoxycarbostyryl, etc.) shown by the formula III. For example, the compound shown by the formula I is obtained by reacting an aniline derivative shown by the formula IV with a carboxylic acid shown by the formula A-COOH or its active compound. A compound (above-mentioned intermediate for drugs) shown by the formula V is obtained by the catalytic reduction of the compound shown by the formula III, or a followed by hydrolysis when R1 and R2 are alkyl.
YOU NAGAO
FUJIOKA TERUO
NAKAGAWA KAZUYUKI
