Dimethyl Sulfate → 3,4,5-Tribromo-1-methyl-1H-pyrazole
Reaction equation
[Br:1][C:2]1[C:6]([Br:7])=[C:5]([Br:8])[NH:4][N:3]=1.[OH-].[Na+].S(OC)(O[CH3:15])(=O)=O>>[Br:1][C:2]1[C:6]([Br:7])=[C:5]([Br:8])[N:4]([CH3:15])[N:3]=1Participants
4
Procedure
To 3,4,5-tribromopyrazole (4.5 g, 0.15 mole) in 3N aqueous sodium hydroxide (6 g, 0.15 mole) is added at room temperature with stirring dimethyl sulfate (19 g, 0.15 mole). After 10 minutes a solid separates out. An additional gram of dimethyl sulfate is added and the mixture is stirred for 3 days, filtered and the precipitate water washed and air dried to yield 33 g (73%), mp 85°C. to 86°C. Crystallization from cyclohexane yields desired solid product whose melting point ranges from about 90°C. to 91°C.
Workup
- filtrationfiltered
- washthe precipitate water washed
- customair dried
- customto yield 33 g (73%), mp 85°C. to 86°C
- customCrystallization from cyclohexane
- customyields desired solid product whose
- customranges from about 90°C. to 91°C.
Sources & evidence
- ORD record
- ord-3b5c9fb278934302bfa69dc1ad5b8bcb
- Source dataset
- uspto-grants-1976_07
- Patent number
- US03970754
Reaction notes
Loading…