Patent ID: 6372921
Filing Date: 2002-04-16
Classification: C07C,C07D

Abstract:
A method for producing isochromanone compound of formula (V) wherein R1 and R2 independently of each other represent hydrogen atom or an alkyl group, R3 represents hydrogen atom, halogen atom, an alkoxy group, a hydroxyalkyl group having 2 or more carbon atoms, or a carboxyl group, and n is an integer of 0 to 4, provided that when n is 2 or more, (R3)s may be the same or different, which comprises the steps of:subjecting an o-xylene compound of formula (I) â€ƒwherein the symbols have the same meanings as defined above, to halogenation reaction in gas phase or liquid phase to prepare an &agr;-halogeno-o-xylene compound of formula (II) wherein X represents a halogen atom, and other symbols have the same meanings as defined above; reacting the compound of formula (II) above with hydrogen cyanide or salts thereof to prepare an &agr;-cyano-o-xylene compound of formula (III) â€ƒwherein the symbols have the same meanings as defined above; reacting the compound of formula (III) with halogen to prepare an &agr;-halogeno-&agr;â€²-cyano-o-xylene compound of formula (IV) â€ƒwherein the symbols have the same meanings as defined above; and hydrolyzing the compound of formula (IV) in water or water containing a protic polar solvent under acidic condition.