Triethylamine → HCID 11748816, compound
Reaction equation
[CH2:1]([O:3][C:4](=[O:14])[CH2:5][NH:6][CH2:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)[CH3:2].C(N([CH2:20][CH3:21])CC)C>C(O)C>[CH2:1]([O:3][C:4](=[O:14])[CH2:5][C@@H:20]([N:6]([CH2:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)[CH2:5][C:4]([O:3][CH2:1][CH3:2])=[O:14])[CH3:21])[CH3:2]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 0 °C
Procedure
To ethanol (55 ml) cooled to 0° C. was added acetyl bromide (41 ml, 0.6 mol) dropwise, followed by a solution of (S)-4-methyl-dihydro-furan-2-one (Tetrahedron 1983, 39, 3107; 18.6 g, 0.2 mol) in ethanol (20 ml). The ice bath was removed and the reaction allowed to reach room temperature. After 2 h of stirring the reaction was concentrated, the residue redissolved in dichloromethane, washed with sat. aq. sodium hydrogencarbonate solution, dried (Na2SO4) and concentrated affording (S)-4-bromo-3-methyl-butyric acid ethyl ester (33.6 g, quantitative). This was redissolved in ethanol (100 ml), cooled to 0° C. and N-benzylglycine ethyl ester (28.2 g, 0.14 mol) and triethylamine (22.4 ml, 0.16 mmol) were added. The reaction was then warmed to 75° C. for 4 d after which time the reaction was concentrated, the residue redissolved in dichloromethane, washed with sat. aq. sodium hydrogencarbonate solution, dried (Na2SO4) and concentrated. Purification by flash column chromatography (ethyl acetate/heptane 5:95) afforded the titled product as a light gold oil (20.3 g, 43%). MS (ISP)=322.2 (M+H)+.
Workup
- temperatureThe reaction was then warmed to 75° C. for 4 d after which time the reaction
- concentrationwas concentrated
- dissolutionthe residue redissolved in dichloromethane
- washwashed with sat. aq. sodium hydrogencarbonate solution
- dry with materialdried (Na2SO4)
- concentrationconcentrated
- customPurification by flash column chromatography (ethyl acetate/heptane 5:95)
Sources & evidence
- ORD record
- ord-54b2263b039a422395e8084b0ca45f81
- Source dataset
- uspto-grants-2011_12
- Patent number
- US08071586B2
Reaction notes
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