Toluene → 1,1-Dimethylethyl N-((1S,2S)-3-chloro-2-hydroxy-1-(phenylmethyl)propyl)carbamate
Reaction equation
[C:1]([O:5][C:6]([NH:8][C@@H:9]([CH2:14][C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)[C:10](=[O:13])[CH2:11][Cl:12])=[O:7])([CH3:4])([CH3:3])[CH3:2].C1(C)C=CC=CC=1.[BH4-].[Na+]>C(O)C>[C:1]([O:5][C:6]([NH:8][C@@H:9]([CH2:14][C:15]1[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=1)[C@H:10]([OH:13])[CH2:11][Cl:12])=[O:7])([CH3:4])([CH3:2])[CH3:3]Participants
Conditions
- Temperature
- 60 °C
Procedure
To (3S)-3-tert-butoxycarbonylamino-1-chloro-4-phenyl-2-butanone (2.08 g) were added toluene (4.2 ml) and ethanol (16.7 ml). Sodium borohydride (133 mg) was added by portions at −10° C. and the mixture was stirred for 1 hr and 40 min. The reaction was quenched by adding acetic acid (0.40 ml). The reaction mixture was warmed to 60° C. over 1 hr and further stirred 60° C. for 30 min. The reaction mixture was then cooled to −10° C. over 1 hr and 50 min and further stirred at −10° C. for 6 hr. The obtained crystals were collected by filtration, washed with toluene (10.4 ml) and water of 0° C., and dried under reduced pressure to give the objective (2S,3S)-3-tert-butoxycarbonylamino-1-chloro-2-hydroxy-4-phenylbutane (1.52 g, yield 83%). The obtained dry crystals were analyzed by HPLC and found to be (2S,3S):(2R,3S)=99.2:0.8 crystals.
Workup
- customThe reaction was quenched
- additionby adding acetic acid (0.40 ml)
- temperatureThe reaction mixture was then cooled to −10° C. over 1 hr and 50 min
- stirringfurther stirred at −10° C. for 6 hr
- filtrationThe obtained crystals were collected by filtration
- washwashed with toluene (10.4 ml) and water of 0° C.
- customdried under reduced pressure
Sources & evidence
- ORD record
- ord-e72c11be57ad4020a7c787678bb2790c
- Source dataset
- uspto-grants-2004_10
- Patent number
- US06806384B2
Reaction notes
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