hydroxylammonium sulfate; ethanol; toluene;
reactants are commercially availlable.
pfizer inc., ep150984, b1, (1991) (i) ethyl 5-methylisoxazol-3-carboxylate a mixture of 0.16 mole ethyl 2,4-dioxovalerate and 0.08 mol e hydroxylamine sulfate, 50 ml ethanol and 70 ml toluene was stirred at 40°c. for four hours. the mixture was cooled to 15-20°c., 1.8 g of concentrated ammonium hydroxide added and stirring continu ed at room temperature for 60 hours. the mixture was poured into water/toluene, the aqueous layer e xtracted with toluene, the organic layers combined, washed with brine and dried (na2so4). evaporation of solvent in vacuo gave a yellow liquid which was distilled to afford 14.68 g of product, b.p. 12 0-124°c. at 30 torr which crystallized upon standing.
feel free to call us on
drop us a line anytime at
and we’ll get back soon.
come visit us at 2 qiande road, life science high tech zone, jiang ning district, nanjing, jiangsu province, china