Dimethyl Sulfate → (3R,5S)-5-biphenyl-4-ylmethyl-1-(2,2-dimethylpropionyl)-3-methylpyrrolidin-2-one

HRID 882513Notes

Reaction equation

[C:1]1([C:20]2[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=2)[CH:6]=[CH:5][C:4]([CH2:7][C@H:8]2[N:12]([C:13](=[O:18])[C:14]([CH3:17])([CH3:16])[CH3:15])[C:11](=[O:19])[CH2:10][CH2:9]2)=[CH:3][CH:2]=1.[CH3:26][Si]([N-][Si](C)(C)C)(C)C.[K+].S(OC)(OC)(=O)=O>C1(C)C=CC=CC=1>[C:1]1([C:20]2[CH:21]=[CH:22][CH:23]=[CH:24][CH:25]=2)[CH:2]=[CH:3][C:4]([CH2:7][C@H:8]2[N:12]([C:13](=[O:18])[C:14]([CH3:16])([CH3:17])[CH3:15])[C:11](=[O:19])[C@H:10]([CH3:26])[CH2:9]2)=[CH:5][CH:6]=1

Participants

Conditions

Temperature: 0 °C

Procedure

10 g of (S)-5-biphenyl-4-ylmethyl-1-(2,2-dimethylpropionyl)pyrrolidin-2-one (1-a, R1=pivaloyl) were dissolved in 150 ml toluene. The mixture was cooled to about 0° C. and 71.5 ml potassium bis(trimethylsilyl)amide solution (0.5 M in toluene) were added. After 15 min, 11 ml dimethyl sulphate were added and the mixture was stirred for a further hour. The reaction was quenched with ammonium chloride solution and extracted with ethyl acetate. The combined organic phases were concentrated to dryness to obtain 15.3 g of crude (3R,5S)-5-biphenyl-4-ylmethyl-1-(2,2-dimethylpropionyl)-3-methylpyrrolidin-2-one. According to HNMR analysis, on the crude, the ratio of diastereoisomers is 83:17 [(3R,5S):(3S,5S)]. Spectroscopic data for (2-a, R1=Pivaloyl) is reported in Example 5-1, Method 1. Spectroscopic data for (2-b, R1=Pivaloyl) is reported in Example 5-2.

Workup

customThe reaction was quenched with ammonium chloride solution
extractionextracted with ethyl acetate
concentrationThe combined organic phases were concentrated to dryness

Sources & evidence

ORD record: ord-2512c418bd5d4d6ab404a539bb1aab26
Source dataset: uspto-grants-2015_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08993785B2

Reaction notes

Loading…