反应详情

Using the procedure of Example 19, 1.32 g (10 mmoles) of 5-mercapto-2-methyl-1,3,4-thiadiazole were silylated with 2.6 ml (15 mmoles) of hexamethyldisilazane in 10 ml of toluene and 2.6 ml of hexamethylphosphoric triamide using 5 mg (0.027 mmole) of saccharin as a catalyst by refluxing for 1.5 hour. After concentration by evaporation, 5 ml of acetonitrile were added thereto and the solution obtained was heated at 50° C. while 2.1 ml (20 mmoles) of butyl bromide were added. The conversion was complete after stirring for 3 hours at this temperature and according to quantitative HPLC analysis, there had been formed 8.91 mmoles (89.1%) of 5-butylthio-2-methyl-1,3,4-thiadiazole, while 5.3% of 3-butyl-5-methyl-Δ4 -1,3,4-thiadiazoline-2-thione was found as a by-product.

1. temperatureby refluxing for 1.5 hour
2. concentrationAfter concentration
3. customby evaporation, 5 ml of acetonitrile
4. additionwere added
5. customthe solution obtained
6. additionwere added