Dimethyl Sulfoxide → tert-butyl N-(1-oxopropan-2-yl)carbamate

HRID 1726373Notes

Reaction equation

HRID 1726373 reaction equation
[C:1]([O:5][C:6](=[O:12])[NH:7][C@H:8]([CH3:11])[CH2:9][OH:10])([CH3:4])([CH3:3])[CH3:2].C(Cl)(=O)C(Cl)=O.CS(C)=O>C(Cl)Cl>[C:1]([O:5][C:6](=[O:12])[NH:7][CH:8]([CH3:11])[CH:9]=[O:10])([CH3:4])([CH3:2])[CH3:3]

Participants

5

Reactant 3

HCID 679Dimethyl SulfoxideHCID 65578Oxalyl chlorideHCID 13200309tert-butyl N-((2R)-1-hydroxypropan-2-yl)carbamate

Product 1

HCID 545705tert-butyl N-(1-oxopropan-2-yl)carbamateYield 101.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

(R)-(2-hydroxy-1-methyl-ethyl)-carbamic acid tert-butyl ester (2.0 g, 11.4 mmol) in 10 mL of CH2Cl2 was added dropwise to a stirred solution of oxalyl chloride (1.1 mL, 12.6 mmol) and DMSO (1.62 mL, 22.8 mmole) in 20 mL of CH2Cl2 at −60° C. The reaction mixture was stirred for 5 minutes before TEA (5.6 ml, 57.1 mmole) was added slowly. The resultant reaction mixture was warmed to room temperature over 1 hour. The organics were washed with water, and the aqueous fractions back extracted with CH2Cl2. The organics were combined and dried over sodium sulfate. The solvent was evaporated under reduced pressure to provide 2.0 g (99%) of (1-methyl-2-oxo-ethyl)-carbamic acid tert-butyl ester (Intermediate VIa) (1H-NMR (CDCl3, ppm) 1.34 d (3H); 1.45 s (9H); 3.10 q (1H); 9.45 (1H)).

Workup

  1. additionwas added slowly
  2. customThe resultant reaction mixture
  3. washThe organics were washed with water
  4. extractionthe aqueous fractions back extracted with CH2Cl2
  5. dry with materialdried over sodium sulfate
  6. customThe solvent was evaporated under reduced pressure

Sources & evidence

ORD record
ord-11e05ac6db1e462b85991e4feeeb337a
Source dataset
uspto-grants-2009_02
Patent number
US07491821B2

Reaction notes

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