Sodium hydride → (2S)-1-((tert-butoxy)carbonyl)-4-methylidenepyrrolidine-2-carboxylic acid
Reaction equation
[CH2:1]=P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.[H-].[Na+].[C:23]([O:27][C:28]([N:30]1[CH2:34][C:33](=O)[CH2:32][C@H:31]1[C:36]([OH:38])=[O:37])=[O:29])([CH3:26])([CH3:25])[CH3:24].C([O-])(O)=O.[Na+]>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.C1COCC1>[C:23]([O:27][C:28]([N:30]1[CH2:34][C:33](=[CH2:1])[CH2:32][C@H:31]1[C:36]([OH:38])=[O:37])=[O:29])([CH3:26])([CH3:25])[CH3:24]Participants
7
Reactant 4
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- 50 °C
Procedure
To a solution of methylenetriphenyl phosphorane, previously prepared from 37 g (777 mmol, 50% NaH in mineral oil, 4 eq) and 277.6 g (777 mmol, 4 eq) methyltriphenyl-phosphonium bromide in 1.5 l THF by stirring at 50° C. for 4 h, were added 44.5 g (194 mmol, leq) (2S)-4-Oxo-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester in 300 ml over a period of 30 min at RT. The suspension was stirred at 50° C. over night. After cooling to RT the suspension was added to a 5% NaHCO3 solution, washed with ether, the inorganic phase was acidified and extracted with EtOAc, washed with brine, dried over Na2SO4 and evaporated. 32.1 g (72%) (2S)-4-Methylene-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester were isolated as white solid.
Workup
- stirringThe suspension was stirred at 50° C. over night
- temperatureAfter cooling to RT the suspension
- washwashed with ether
- extractionextracted with EtOAc
- washwashed with brine
- dry with materialdried over Na2SO4
- customevaporated
Sources & evidence
- ORD record
- ord-b80e27ded7964b69b31111c08b54f075
- Source dataset
- uspto-grants-2004_09
- Patent number
- US06790860B2
Reaction notes
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