2-Propanol, 2-methyl-, lithium salt (1:1) → (r)-5-Biphenyl-4-ylmethyl-3-[1-diisopropylamino-meth-(e)-ylidene]-2-oxo-pyrrolidine-1-carboxylic acid tert-butyl ester

HRID 2174871Notes

Reaction equation

HRID 2174871 reaction equation
C[C:2]([CH3:5])([O-])[CH3:3].[Li+].[C:7]([O:11][C:12]([N:14]1[C:18](=[O:19])[CH2:17][CH2:16][C@H:15]1[CH2:20][C:21]1[CH:26]=[CH:25][C:24]([C:27]2[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=2)=[CH:23][CH:22]=1)=[O:13])([CH3:10])([CH3:9])[CH3:8]>O1CCCC1>[C:7]([O:11][C:12]([N:14]1[C@H:15]([CH2:20][C:21]2[CH:22]=[CH:23][C:24]([C:27]3[CH:28]=[CH:29][CH:30]=[CH:31][CH:32]=3)=[CH:25][CH:26]=2)[CH2:16]/[C:17](=[CH:12]\[N:14]([CH:15]([CH3:20])[CH3:16])[CH:2]([CH3:5])[CH3:3])/[C:18]1=[O:19])=[O:13])([CH3:10])([CH3:8])[CH3:9]

Participants

4

Reactant 2

HCID 236647642-Propanol, 2-methyl-, lithium salt (1:1)HCID 46193436(S)-2-biphenyl-4-ylmethyl-5-oxopyrrolidine-1-carboxylic acid t-butyl ester

Product 1

HCID 58160400(r)-5-Biphenyl-4-ylmethyl-3-[1-diisopropylamino-meth-(e)-ylidene]-2-oxo-pyrrolidine-1-carboxylic acid tert-butyl ester

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
60 °C

Procedure

A mixture of lithium tert-butoxide (2.8 eq, 2.8 mmol, 1 M solution in THF) and N,N,N′N′-tetramethylformamidinium chloride (18, R6=Me, R7=Me) (3 eq, 3 mmol) are stirred at 60° C. for 1 h. The mixture is then cooled to room temperature. The mixture is then diluted with tetrahydrofuran to a total volume of 5 ml. (S)-2-Biphenyl-4-ylmethyl-5-oxo-pyrrolidine-1-carboxylic acid tert-butyl ester (8-a, R1=Boc) (1 eq, 1 mmol) is then added to the mixture. The mixture is then stirred at room temperature for 3 h. The volatiles are removed under reduced pressure. Ethyl acetate (20 ml) is added to the mixture. The phases are separated and the organic phase is washed with saturated sodium carbonate solution (2×20 ml) and brine (20 ml). The organic phase is dried (Na2SO4) and concentrated under reduced pressure to afford (R)-5-Biphenyl-4-ylmethyl-3-[1-dimethylaminometh-(E/Z)-ylidene]-2-oxo-pyrrolidine-1-carboxylic acid tert-butyl ester (7-a, R1=Boc, R6=Me, R7=Me) or a salt thereof. The solutions are analysed by TLC (50% ethyl acetate in hexane). RF 0.21 (salt of 7-a, R1=Boc, R6=Me, R7=Me); RF 0.27 (7-a, R1=Boc, R6=Me, R7=Me); RF 0.68 (8-a, R1=Boc).

Workup

  1. temperatureThe mixture is then cooled to room temperature
  2. stirringThe mixture is then stirred at room temperature for 3 h
  3. customThe volatiles are removed under reduced pressure
  4. additionEthyl acetate (20 ml) is added to the mixture
  5. customThe phases are separated
  6. washthe organic phase is washed with saturated sodium carbonate solution (2×20 ml) and brine (20 ml)
  7. dry with materialThe organic phase is dried (Na2SO4)
  8. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-017b63cdf93f405fb2790583a0763aaf
Source dataset
uspto-grants-2015_06
Patent number
US09061973B2

Reaction notes

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