PURIFICATION OF 3,4,5,6-TETRAHYDROPHTHALIC ANHYDRIDE

    公开(公告)号:JPH03188073A

    公开(公告)日:1991-08-16

    申请号:JP32669889

    申请日:1989-12-15

    Abstract: PURPOSE:To purify 1-THPA useful as a synthetic intermediate for insecticide, herbicide, etc., by recrystallizing an acid anhydride mixture composed mainly of 1-THPA in water and/or an alcohol solvent. CONSTITUTION:An acid anhydride mixture composed mainly of 3,4,5,6- tetrahydrophthalic anhydride (abbreviated as 1-THPA) is mixed with water and/or a monohydric and/or polyhydric alcohol of formula R(OH)n (R is residue obtained by removing OH from a 1-22C monohydric or polyhydric alcohol; n is 1-3) and the mixture is stirred and melted by heating at 50-160 deg.C. The molten mixture is cooled and the precipitated crystal is separated and dried under reduced pressure to obtain the objective compound having high purity. The objective compound can be purified also by hydrolyzing or monoesterifying the existing phthalic anhydrides with a solvent and dissolving and removing the hydrolyzate, etc.

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