Potassium Carbonate → tert-Butyl (2S)-but-3-yn-2-ylcarbamate

HRID 57408Notes

Reaction equation

HRID 57408 reaction equation
[C:1]([O:5][C:6](=[O:12])[NH:7][C@@H:8]([CH3:11])[CH:9]=O)([CH3:4])([CH3:3])[CH3:2].[CH3:13]OP(C(=[N+]=[N-])C(=O)C)(=O)OC.C(=O)([O-])[O-].[K+].[K+]>CO.C(OCC)(=O)C.[Cl-].[Na+]>[CH3:11][C@H:8]([NH:7][C:6](=[O:12])[O:5][C:1]([CH3:4])([CH3:3])[CH3:2])[C:9]#[CH:13]

Participants

7

Reactant 3

HCID 11430Potassium CarbonateHCID 7015728tert-butyl N-((2S)-1-oxopropan-2-yl)carbamateHCID 136023029(1E)-1-diazo-1-dimethoxyphosphorylpropan-2-one

Product 1

HCID 10986677tert-Butyl (2S)-but-3-yn-2-ylcarbamateYield 53%

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 5234Sodium ChlorideSolventHCID 8857Ethyl AcetateSolvent

Procedure

A solution of (S)-tert-butyl(1-oxopropan-2-yl)carbamate (500 mg, 2.89 mmol), dimethyl(1-diazo-2-oxopropyl)phosphonate (610 mg, 3.18 mmol, 1.1 equiv), and potassium carbonate (638 mg, 4.62 mmol, 1.6 equiv) in methanol (14.4 mL) was stirred at room temperature for 18 hours. The reaction was then diluted with ethyl acetate (30 mL) and saturated aqueous sodium chloride (40 mL). The layers were separated and the aqueous layer was extracted with ethyl acetate (30 mL) and the combined organic extracts were dried over Na2SO4, filtered and concentrated. Silica gel column chromatography (20% EtOAc in Heptane) provided (S)-tert-butyl but-3-yn-2-ylcarbamate (0.258 g, white solid) in 53% yield. 1H NMR (400 MHz, CDCl3) δ 4.49 (m, 1H), 2.26 (d, J=2.2 Hz, 1H), 1.46 (s, 9H), 1.41 (d, J=6.8 Hz, 3H).

Workup

  1. customThe layers were separated
  2. extractionthe aqueous layer was extracted with ethyl acetate (30 mL)
  3. dry with materialthe combined organic extracts were dried over Na2SO4
  4. filtrationfiltered
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-3b3c45eaca954158b78654fa10bad086
Source dataset
uspto-grants-2016_09
Patent number
US09434719B2

Reaction notes

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