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    • 30. 发明专利
    • PRODUCTION OF PHTHALIDE COMPOUND
    • JPS6280A
    • 1987-01-06
    • JP13719085
    • 1985-06-24
    • MITSUBISHI CHEM IND
    • TANIGUCHI SEIROMORITA YOSHIMIHAYAKAWA SHUZO
    • C07D307/88
    • PURPOSE:To obtain the objective compound in high yield suppressing the production of by-product, by using a specific amount of hydrochloric acid in the process for the production of a phthalide by the reaction of a trialkoxybenzoic acid with formaldehyde in the presence of hydrochloric acid. CONSTITUTION:The phthalide compound of formula III useful as an intermediate for tritoqualine (a medicine having anti-allergy action, etc.) is produced by reacting the trialkoxybenzoic acid of formula I (R -R are lower alkyl) with formaldehyde in the presence of hydrochloric acid. In the above process, the amount of the hydrochloric acid is selected to 1/100-1/200pts.wt. per 1pt. of the sum of formaldehyde and water in terms of hydrogen chloride. The by- production of 7-chloromethyl-4,5,6-trialkoxyphthalide can be suppressed and the yield of the objective compound can be improved by this process. The amount of formaldehyde is preferably 3-20mol per 1mol of the compound of formula I, and the reaction temperature is preferably 70-110 deg.C.