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

HRID 871647Notes

Reaction equation

HRID 871647 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) δ 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-d53993da51c849a1b7bb68680db35cc1
Source dataset
uspto-grants-2015_03
Patent number
US08969587B2

Reaction notes

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