反应详情

Methyl-p-benzoquinone 12.2 g, 0.1 mole) and 2-mercaptoethanol (3.9 g, 0.05 mole) are mixed in absolute ethanol (70 ml) under nitrogen and with stirring. The temperature rises to 50° C. The mixture is cooled in a bath of ice-water and left to stand, with stirring, for 2 hours at ambient temperature. The solution is concentrated under vacuum and the oil obtained is chromatographed on Silica 60 (eluent: dichloromethane). According to 1H and 13C NMR, a first fraction (3 g) is a 50/50 mixture of two products: 2-hydroxyethylthio-5-methyl-1,4-benzoquinone and 2-hydroxyethylthio-6-methyl-1,4-benzoquinone. A second fraction gives the expected product:

1. customrises to 50° C
2. waitleft
3. stirringwith stirring, for 2 hours at ambient temperature
4. concentrationThe solution is concentrated under vacuum
5. customthe oil obtained
6. customis chromatographed on Silica 60 (eluent: dichloromethane)
7. additiona 50/50 mixture of two products