反应详情

温度

140 °C

To a mixture of 26.5 g (0.34 moles) 2-mercaptoethanol, 19 g of 85% potassium hydroxide, and a few drops of 18-Crown-6 in 250 ml of DMSO, 60 g (0.32 moles) 1-methyl-3,4,5-trichloropyrazole were added in portions. When the addition was complete, the reaction mixture was heated to 140° C. for 1 day. The cooled reaction mixture was diluted with water and extracted with ether. The organic phase was washed four times with 200 ml water per time, dried and stripped. The crude product was chromatographed on a silica gel column. The product, 1-methyl-3,4-dichloro-5-(2-hydroxyethylthio)pyrazole, was eluted from the column with ethyl acetate, yielding 27.7 g (37.7% yield) of a yellow oil.

1. additionwere added in portions
2. additionWhen the addition
3. customThe cooled reaction mixture
4. extractionextracted with ether
5. washThe organic phase was washed four times with 200 ml water per time
6. customdried
7. customThe crude product was chromatographed on a silica gel column
8. washThe product, 1-methyl-3,4-dichloro-5-(2-hydroxyethylthio)pyrazole, was eluted from the column with ethyl acetate