Phosphorus oxybromide → 1-(5-(Bromomethyl)-3-nitro-1H-pyrazol-1-yl)propan-2-ol
Reaction equation
O[CH2:2][C:3]1[N:7]([CH2:8][CH:9]([OH:11])[CH3:10])[N:6]=[C:5]([N+:12]([O-:14])=[O:13])[CH:4]=1.P(Br)(Br)([Br:17])=O>C(Cl)(Cl)Cl>[Br:17][CH2:2][C:3]1[N:7]([CH2:8][CH:9]([OH:11])[CH3:10])[N:6]=[C:5]([N+:12]([O-:14])=[O:13])[CH:4]=1Participants
4
Conditions
- Temperature
- 0 °C
Procedure
To a mixture of 250a (4.0 g, 20.0 mmol) in chloroform (100 mL) cooled at 0° C. was added the solution of POBr3 (22.9 g, 80 mmol) in chloroform (20 mL) over 30 minutes while maintaining the internal temperature below 5° C. The reaction mixture was warmed to 50° C. and stirred at this temperature for 3 h. It was then cooled to 0° C. and quenched with water. The organic layer was separated and evaporated under reduced pressure. The residue was purified by silica-gel column chromatography eluting with 30:1 dichloromethane/methanol to afford 250b (3.3 g, 62%) as yellow solid. MS-ESI: [M+H]+ 264.1
Workup
- temperaturewhile maintaining the internal temperature below 5° C
- temperatureThe reaction mixture was warmed to 50° C.
- temperatureIt was then cooled to 0° C.
- customquenched with water
- customThe organic layer was separated
- customevaporated under reduced pressure
- customThe residue was purified by silica-gel column chromatography
- washeluting with 30:1 dichloromethane/methanol
Sources & evidence
- ORD record
- ord-29e01d4caf7e4a63a3b9da13d9521d0f
- Source dataset
- uspto-grants-2016_01
- Patent number
- US09238655B2
Reaction notes
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