Methyl N-(triethylammoniosulfonyl)carbamate → Ethyl (4S)-2-{(1R)-1-[2-(tert-butoxy)-2-oxoethyl]4-cyclohexylbutyl}-4,5-dihydro-1,3-oxazole-4-carboxylate

HRID 1350257Notes

Reaction equation

HRID 1350257 reaction equation
[CH:1]1([CH2:7][CH2:8][CH2:9][C@@H:10]([C:19]([NH:21][C@@H:22]([CH2:28][OH:29])[C:23]([O:25][CH2:26][CH3:27])=[O:24])=O)[CH2:11][C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1.CC[N+](S(N=C(OC)[O-])(=O)=O)(CC)CC>C1COCC1>[C:15]([O:14][C:12](=[O:13])[CH2:11][C@H:10]([C:19]1[O:29][CH2:28][C@@H:22]([C:23]([O:25][CH2:26][CH3:27])=[O:24])[N:21]=1)[CH2:9][CH2:8][CH2:7][CH:1]1[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6]1)([CH3:16])([CH3:18])[CH3:17]

Participants

4

Reactant 2

HCID 2724994Methyl N-(triethylammoniosulfonyl)carbamateHCID 59909824tert-butyl(3R)-6-cyclohexyl-3-({[(1S)-2-ethoxy-1-(hydroxymethyl)-2-oxoethyl]amino}carbonyl)hexanoate

Product 1

HCID 59909855Ethyl (4S)-2-{(1R)-1-[2-(tert-butoxy)-2-oxoethyl]4-cyclohexylbutyl}-4,5-dihydro-1,3-oxazole-4-carboxylateYield 97%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of tert-butyl(3R)-6-cyclohexyl-3-({[(1S)-2-ethoxy-1-(hydroxymethyl)-2-oxoethyl]amino}carbonyl)hexanoate (preparation 151) (10.09, 24.2 mmol) in THF (80 ml) was treated with Burgess reagent (6.34 g, 26.6 mmol) and heated at reflux for 1 hour. The reaction mixture was allowed to cool to room temperature and stored in a fridge for 3 days. The solvent was removed under reduced pressure. The crude material was ourififed on a silica column eluting with a solvent gradient of pentane:EtOAc (100:0) gradually changing to (80:20) to afford the title compound as a colourless oil (9.26 g, 97%).

Workup

  1. temperatureheated
  2. temperatureat reflux for 1 hour
  3. customThe solvent was removed under reduced pressure
  4. washeluting with a solvent gradient of pentane:EtOAc (100:0)

Sources & evidence

ORD record
ord-976a9592d5a4491697bd15db54dd5c75
Source dataset
uspto-grants-2007_05
Patent number
US07214694B2

Reaction notes

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