Oxalyl chloride → (2R,3R)-N,N-bis-(tert-butoxycarbonylmethyl)-2,3-epoxybutyramide
Reaction equation
C(Cl)(=O)C(Cl)=O.CCCCC(F)(F)C(O)CC[C@@H]1[C@@H:20](CCCCCCC(O)=O)[C:18](=[O:19])[CH2:17][C@H:16]1[OH:30].C1CCC(NC2CCCCC2)CC1.[NH:47]([CH2:56][C:57]([O:59][C:60]([CH3:63])([CH3:62])[CH3:61])=[O:58])[CH2:48][C:49]([O:51][C:52]([CH3:55])([CH3:54])[CH3:53])=[O:50]>C(Cl)Cl.CN1CCOCC1>[C:60]([O:59][C:57]([CH2:56][N:47]([CH2:48][C:49]([O:51][C:52]([CH3:55])([CH3:54])[CH3:53])=[O:50])[C:16](=[O:30])[C@@H:17]1[O:19][C@@H:18]1[CH3:20])=[O:58])([CH3:62])([CH3:63])[CH3:61]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 2
Procedure
A solution of 11.6 g of oxalyl chloride in 25 ml of methylene chloride is added dropwise, in the course of 15 minutes, to a mixture, cooled to -25°, of 20 g of dimethylforinaniide and 115 ml of methylene chloride. The white suspension is stirred for a further 20 minutes at -25°, and a solution of 28.5 g of the dicyclohexylammonium salt of (2R,3R,)-2,3-epoxybutyric acid in 115 ml of methylene chloride is then added in the course of 10 minutes. The reaction mixture is stirred for a further 20 minutes at the same temperature, and a solution of 17.87 g of di-tert-butyl iminodiacetate in 90 ml of methylene chloride and 9.22 ml of N-methylmorpholine are then added dropwise simultaneously in the course of 15 minutes. The cooling bath is removed and the reaction mixture is stirred for 3 hours at room temperature. The white suspension is then filtered through a sintered glass suction filer, the residue is washed with methylene chloride, and the filtrate is diluted with methylene chloride and washed successively with water, 5% aqueous citric acid, saturated aqueous sodium bicarbonate solution and water. The aqueous phases are subsequently extracted twice with methylene chloride, and the combined organic phases are dried and evaporated under a water pump vacuum. The yellow-brown crude product is purified by flash chromatography over silica gel (Merck 9385) using a 9:1 mixture of methylene chloride and ethyl acetate as the mobile phase. (2R,3R)-N,N-Bis-(tert-butoxy-carbonylmethyl)-2,3-epoxybutyramide is obtained in the form of a pale yellow oil, [α]D =+52° (c=1.250% in chloroform).
Workup
- stirringThe reaction mixture is stirred for a further 20 minutes at the same temperature
- customThe cooling bath is removed
- stirringthe reaction mixture is stirred for 3 hours at room temperature
- filtrationThe white suspension is then filtered through a sintered glass suction filer
- washthe residue is washed with methylene chloride
- additionthe filtrate is diluted with methylene chloride
- washwashed successively with water, 5% aqueous citric acid, saturated aqueous sodium bicarbonate solution and water
- extractionThe aqueous phases are subsequently extracted twice with methylene chloride
- customthe combined organic phases are dried
- customevaporated under a water pump vacuum
- customThe yellow-brown crude product is purified by flash chromatography over silica gel (Merck 9385)
- additiona 9:1 mixture of methylene chloride and ethyl acetate as the mobile phase
Sources & evidence
- ORD record
- ord-76d50f2d7a4c4fd6b0b7a98b54643f2b
- Source dataset
- uspto-grants-1994_05
- Patent number
- US05317100
Reaction notes
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