tert-butyl 3-methylisoxazol-4-ylcarbamate synthesis

Yield:1285517-11-4 66%

Reaction Conditions:

with diphenyl phosphoryl azide;triethylamine at 50 - 90; for 16 h;

Steps:

56 Preparation of tert-butyl (3-methylisoxazol-4-yl)carbamate

[0267j Diphenyl phosphorazidate (642 mg, 2.34 mmol) and TEA (236 mg, 2.34 mmol) were added to a solution of 3-methylisoxazole-4-carboxylic acid (300 mg, 2.34 mmol) in tertbutanol (10 mL) at 50 °C. The mixture was stirred at 90 °C for 16 h. After concentrated, the residue was purified by silica gel column chromatography (petroleum ether/EtOAc =1:4) to give tert-butyl (3-methylisoxazol-4-yl)carbamate (412 mg, yield: 66%) as a yellow solid. ESI-MS (M+H): 199.1.

References:

WO2015/89337,2015,A1 Location in patent:Paragraph 0267