反应详情

2,3-Dimethoxy-5-methyl-6-(9'-carboxynonyl)-1,4-benzoquinone (formula I-2 wherein R=H3CO, n=8, in the free form) (4 parts) was esterified with methanol (500 volume parts) saturated with hydrogen chloride gas in a manner similar to that described in Example 13. The procedure provided 2,3-dimethoxy-5-methyl-6-(9'-methoxycarbonylnonyl)-1,4-benzoquinone (formula I-2 wherein R=H3CO, n=8, in the form of methyl ester) (4.2 parts) as orange-colored needles melting at 37°-37.5° C.