反应详情

温度

0 °C

Potassium nitrosodisulfonate (0.9 part) was added to a solution of 6-(2'-hydroxy-3',4',6'-trimethylphenyl)hexanoic acid (formula II-2 wherein R=H3C, X=H, Y=OH, n=4, in the free form) (0.111 part) in 1% sodium hydroxide (5 volume parts) and water (3 volume parts) and the mixture was stirred at room temperature for 30 minutes. Then, the reaction mixture was cooled to 0° C. and, following the addition of cold water (50 volume parts), it was rendered acidic with dilute hydrochloric acid, whereupon a yellow precipitate was obtained. Recrystallization of this precipitate from hexane-ethyl acetate (10:1) provided 2,3,5-trimethyl-6-(5'-carboxypentyl)-1,4-benzoquinone (formula I-2 wherein R=H3C, n=4, in the free form) (0.11 part) as yellow needles melting at 81°-82° C.

1. customwas obtained
2. customRecrystallization of this precipitate from hexane-ethyl acetate (10:1)