5-cyanoisoxazole synthesis

Yield:-

Reaction Conditions:

with trichlorophosphate in N-methyl-acetamide;ice-water;

Steps:

1 Isoxazole-5-carboxamide oxime

EXAMPLE 1 Isoxazole-5-carboxamide oxime To a solution of 2.80 g (25.0 mmol) of 5-isoxazole carboxamide in 30 ml of dimethylformamide was added dropwise 2.80 ml (30.3 mmol) of phosphorus oxychloride under ice-cooling. After this addition, the mixture was raised to room temperature and stirred for 1 hour. The reaction mixture was poured into 100 ml of ice-water and extracted with 100 ml of ethyl acetate. The aqueous layer was subjected to salting-out and extracted twice with 100 ml of ethyl acetate. The ethyl acetate extracts were combined, dried over magnesium sulfate anhydride and concentrated to give 5-cyanoisoxazole as pale yellow oily matter. This product was dissolved by adding 30 ml of methanol, then 2.32 g (32.5 mmol) of hydroxylamine hydrochloride was added, and 4.55 ml (32.5 mmol) of triethylamine was further added, and the mixture was stirred at room temperature for 18 hours.

References:

US6630592,2003,B1