Dimethylformamide dimethyl acetal → (Z)-tert-butyl 3-((dimethylamino)methylene)-4-oxopyrrolidine-1-carboxylate
Reaction equation
[O:1]=[C:2]1[CH2:6][CH2:5][N:4]([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:3]1.[CH3:14][N:15]([CH:17](OC)OC)[CH3:16]>C1COCC1>[CH3:14][N:15](/[CH:17]=[C:6]1/[CH2:5][N:4]([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:3][C:2]/1=[O:1])[CH3:16]Participants
4
Conditions
- Temperature
- 67.5 °C
Procedure
A solution of tert-butyl 3-oxopyrrolidine-1-carboxylate (53.4 kg, 288 mol) in THF (133 kg) was treated with DMF-DMA (103 kg, 864 mol) in THF (472 kg) and heated at 65-70° C. under nitrogen for 20 h. The solution was cooled, evaporated under reduced pressure and solvent switched under distillation to cyclohexane. The resulting slurry was then filtered, cake washed with cyclohexane, and then water. The solids were then dried under vacuum at 35-40° C. to give tert-butyl (3Z)-3-[(dimethylamino)methylene]-4-oxopyrrolidine-1-carboxylate.
Workup
- temperatureThe solution was cooled
- customevaporated under reduced pressure and solvent
- distillationswitched under distillation to cyclohexane
- filtrationThe resulting slurry was then filtered
- washcake washed with cyclohexane
- customThe solids were then dried under vacuum at 35-40° C.
Sources & evidence
- ORD record
- ord-6b8478964e8f4d1cae774154f0fbf95b
- Source dataset
- uspto-grants-2015_11
- Patent number
- US09181262B2
Reaction notes
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