3,5-DIMETHOXY-PHTHALIC ANHYDRIDE synthesis

Yield:4670-17-1 91.2%

Reaction Conditions:

with acetic anhydride at 2;Reflux;

Steps:

e e) Synthesis of 3,5-dimethoxy-phthalic anhydride

9g (0.038mol) of product IV and 36g (0.3529mo1) of acetic anhydride were added to the four-necked flask and heated to reflux for 2h.The reaction is almost complete. After the mixture is cooled, a portion of the pure anhydride crystallizes and is suction filtered;After the filtrate is distilled under reduced pressure, all the acetic acid is distilled off and cooled to obtain another part of pure crystals.The crystallization was recrystallized from benzene and petroleum ether to give the final product 3,5-dimethoxy-phthalic anhydride;Weigh 7.55 g (0.03630 mol) of white floc, yield 91.2%.

References:

CN107759549,2018,A Location in patent:Paragraph 0006