hydroxylamine-O-sulfonic acid → 5-(P-Tolyl)isoxazole

Participants

Reaction Steps

At 0° C. a solution of hydroxylamine-O-sulfonic acid (93 g) in dry methanol (700 ml) is added over 2 min to a solution of crude 3-dimethylamino-1-p-tolylprop-2-en-1-one (148 g) in dry methanol (1 l). The mixture is stirred at ambient temperature for 20 min, then carefully poured into a solution of sodium bicarbonate (150 g) in water (1 l). After standing at room temperature over night (for convenience) the precipitate is collected and dried to give crude 5-(4-methylphenyl)-isoxazole. In order to obtain purer product, the material can be purified by flash cromatography on silica gel, using hexane/ethyl acetate (4:1) as eluent.

Provenance & Evidence