Potassium Carbonate → Phenyl 5-tert-butylisoxazol-3-ylcarbamate

HRID 1918049Notes

Reaction equation

HRID 1918049 reaction equation
[C:1]([C:5]1[O:9][N:8]=[C:7]([NH2:10])[CH:6]=1)([CH3:4])([CH3:3])[CH3:2].C(=O)([O-])[O-].[K+].[K+].Cl[C:18]([O:20][C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1)=[O:19]>C1COCC1>[C:1]([C:5]1[O:9][N:8]=[C:7]([NH:10][C:18](=[O:19])[O:20][C:21]2[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=2)[CH:6]=1)([CH3:4])([CH3:3])[CH3:2]

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 15891Phenyl chloroformateHCID 1714733-Isoxazolamine, 5-(1,1-dimethylethyl)-

Product 1

HCID 13489605Phenyl 5-tert-butylisoxazol-3-ylcarbamateYield 78%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 5-tert-butylisoxazol-3-amine (35.00 g, 250 mmol) in THF (300 mL), potassium carbonate (45.61 g, 330 mmol) and phenyl chloroformate (43.84 g, 280 mmol) were added and the solution stirred at rt overnight. The reaction mixture was filtered through Celite and the pad washed thoroughly with THF. The filtrate was concentrated to a solid and portioned between brine and DCM, then extracted with 2 additional portions of DCM. The combined extracts were dried over magnesium sulfate, filtered and concentrated to a solid. The resulting solid was recrystallized from 10% DCM/ether and hexane. The solid collected by filtration to afford phenyl 5-tert-butylisoxazol-3-ylcarbamate (50.72 g, 78% yield). 1H NMR (300 MHz, DMSO d6) 1.35 (s, 9H), 6.43 (s, 1H), 7.20 (m, 3H), 7.44 (m, 2H).

Workup

  1. filtrationThe reaction mixture was filtered through Celite
  2. washthe pad washed thoroughly with THF
  3. concentrationThe filtrate was concentrated to a solid and portioned between brine and DCM
  4. extractionextracted with 2 additional portions of DCM
  5. dry with materialThe combined extracts were dried over magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated to a solid
  8. customThe resulting solid was recrystallized from 10% DCM/ether and hexane
  9. filtrationThe solid collected by filtration

Sources & evidence

ORD record
ord-bb52a1cbff304101a50b88b7a7c140ce
Source dataset
uspto-grants-2013_12
Patent number
US08618289B2

Reaction notes

Loading…