| 摘要 |
PROBLEM TO BE SOLVED: To obtain a new compound useful as a medicine or the like, especially a manufacturing intermediate for an antiplatelet drug. SOLUTION: This new compound is a compound of formula I (R is H or a lower alkyl), e.g. [6-(benzyloxycarboxamide)-2H-1-benzopyran-3-yl]acetate. The compound of the formula I is obtained by carrying out a dehydration reaction of (A) γ-hydroxycarboxylic acid ester derivative of formula II (R is a lower alkyl), e.g. methyl[6(benzyloxycarboxamide)-4-hydroxy-3,4-dihydro-2H-1- benzopyran-3-yl]acetate) with (B) an acidic ion-exchange resin preferably of a strongly acidic ion-exchange resin of a sulfonic acid type of 1-200 wt.% based on the component A, as a catalyst in the presence of (C) molecular sheaves, preferably powdery molecular sheaves 3A, of about 10-200 wt.% based on the component A at 20-200 deg.C. |
