反应详情

131 g of 2,3-dihydroxy-naphthaldehyde semicarbazone were boiled at reflux overnight with 250 g of powdered potassium hydroxide in 1350 ml of diethyleneglycol under an argon stream in a 1.5 l sulfonation flask equipped with stirrer, condenser, theremometer and calcium chloride tube. The cooled solution was diluted with 4,5 l of water, made acid with 450 ml of concentrated hydrochloric acid and extracted eight times with 1 l ether. The combined ether extracts were dried over sodium sulfate and evaporated in vacuo. Recrystallization from water gave 61.5 g (65.5% of theory) of 1-methyl-2,3-dihydroxy-naphthalene. Melting point 97°-100° C.

1. customequipped with stirrer, condenser
2. extractionextracted eight times with 1 l ether
3. dry with materialThe combined ether extracts were dried over sodium sulfate
4. customevaporated in vacuo
5. customRecrystallization from water