Sodium Nitrite → 1-((3,5-dimethylisoxazol-4-yl)methyl)-1H-pyrazole-4-carbonyl azide

Participants

Reaction Conditions

Reaction Steps

Sodium nitrite (450 mg, 6.5 mmol, in H2O) (10 mL) was added dropwise, over 10 minutes, to a suspension of 1-((3,5-dimethylisoxazol-4-yl)methyl)-1H-pyrazole-4-carbohydrazide (example 10-1b) (1 g, 4.3 mmol) in 10% aqueous acetic acid (50 mL) and cooled to 0° C. via an ice water bath. The reaction was stirred for an additional 15 minutes then extracted with ethyl acetate (3×, 75 mL). The combined organic extracts were washed with aqueous saturated sodium carbonate (100 mL) followed by H2O (100 mL). The combined organic extracts were dried over sodium sulfate, filtered and concentrated. The solid product was triturated with ethyl acetate/hexanes (1/9) and dried en vacuo to afford 1-((3,5-dimethylisoxazol-4-yl)methyl)-1H-pyrazole-4-carbonyl azide (1 g, 93%) as a white solid. 1H NMR (CDCl3, 400 MHz): δ2.20 (s, 3H), 2.44 (s, 3H), 5.07 (s, 2H), 7.81 (s, 1H), 7.93 (s, 1H).

Provenance & Evidence