反应详情

A mixture of 6-chloro-2,3-dihydro-s-triazolo[4,3-b]-pyridazin-3-one [P. Francavilla and F. Lauria, J. Het. Chem., 8, 415 (1971) ] (1.70 g., 0.01 mole) and potassium hydrosulfide (1.44 g., 0.02 mole) in ethanol (30 ml.) was heated in a sealed tube for 8 hours at 140°. After cooling, water (50 ml.) was added to the reaction mixture and a small amount of insoluble material was removed by filtration. The filtrate being concentrated under reduced pressure, the concentrate was acidified to pH 2 with dil. HCl to afford yellow precipitate of 6-mercapto-2,3-dihydro-s-triazolo[4,3-b]pyridazin-3-one which was collected by filtration, washed with water (10 ml.) and dried in vacuo on P2O5. Yield 1.43 g. (84%). M.p. > 300° C.

1. temperaturewas heated in a sealed tube for 8 hours at 140°
2. temperatureAfter cooling
3. customa small amount of insoluble material was removed by filtration
4. concentrationThe filtrate being concentrated under reduced pressure