PURPOSE: To provide a new synthetic method of phthalide derivatives in a high selectivity and a high yield by reacting an acetylene carboxylic acids mixed with a silver salt and/or silver.
CONSTITUTION: This new synthetic method of phthalide derivatives comprises reacting by mixing a compound of formula I (R1 is an alkyl; R2, R3 are each H, an alkyl or R2 and R3 linked to form a ring) with one or more silver salt (e.g. silver iodide, silver chloride, silver carbonate and silver sulfate) and/or silver in an anhydrous aprotic polar solvent (e.g. anhydrous dimethylformamide) with adding amines if necessary at -40 to 100°C to obtain the compounds of formula II. The phthalide derivatives are useful as medicines having the inhibitory effect of prostaglandin F2α, the reducing effect of blood viscosity, the suppressing effect of cell proliferation, etc.
WAKAMATSU TAKESHI
MARUNO MASAO
