tert-Butanol → Tert-butyl (6-methoxypyrazolo[5,1-b][1,3]thiazol-7-yl)carbamate

Participants

Reaction Steps

To a mixture of 6-methoxypyrazolo[5,1-b]thiazole-7-carboxylic acid (300 mg, 1.51 mmol) and 1,4-dioxane (4 mL) were added triethylamine (0.215 mL, 1.54 mmol) and diphenylphosphoryl azide (0.325 mL, 1.51 mmol) while stirring at room temperature, and the mixture was stirred and heated to reflux for 3 hour. After returning the mixture to room temperature, triethylamine (0.631 mL, 4.53 mmol) and tert-butanol (0.289 mL, 3.02 mmol) were added and the mixture was stirred and heated to reflux for 3 hour. After returning the mixture to room temperature, the solvent in the mixture was distilled off under reduced pressure and the residue was purified by silica gel column chromatography (mixture of n-heptane and ethyl acetate: n-heptane/ethyl acetate=1/4) to obtain the title compound (144 mg, 0.535 mmol).

Provenance & Evidence