Catalytic synthesis process of 2-hydroxy-4,6-dimethoxydeoxybenzoin

2-Hydroxy-4,6-dimethoxydeoxybenzoin was synthesized from 1,3,5-trimethoxybenzene,via the Houben-Hoesch reaction or Friedel-Crafts reaction and demethylation of 2,4,6-trimethoxydeoxybenzoin.Because of the protection of methyl group,the reactivity of hydroxy groups was reduced and the yields of Houben-Hoesch and Friedel-Crafts reaction reached to 81.3% and 94.5% respectively.The yield of demethylation was 93.8%.The effects of catalyst amount and reaction temperature were investigated,and the optimal process parameters were as follows:(1)in Friedel-Crafts reaction,the ratio of catalyst(aluminum chloride)and 1,3,5-trimethoxybenzene 1.1∶1,reaction temperature 25 ℃,(2)in demethylation,the ratio of demethylation reagent and 2,4,6-trimethoxydeoxybenzoin 1.2∶1,reaction temperature 82 ℃.The product was characterized with 1H NMR and MS.