Hydrochloric Acid → 1-(2-Isopropylpyrazolo[1,5-a]pyridin-3-yl)-2-methylpropan-1-one oxime

Participants

Reaction Steps

To a solution of 2.3 g (10 mmol) of 1-(2-isopropylpyrazolo[1,5-a]pyridin-3-yl)-2-methylpropan-1-one in 32 ml of anhydrous EtOH was added hydroxylamine hydrochloride 1.5 g (20 mmol), followed by dropwise addition of 2.4 g NaOH in 6 ml of water. The mixture was stirred and refluxed over night. After cooling, the solution was poured into a solution of 8.3 ml of 6N HCl and 380 ml ice water with stirring for 30 minutes. The precipitate was filtered and washed with ethyl ether-hexane to furnish 1.2 g (74.5%) of 1-(2-isopropylpyrazolo[1,5-a]pyridin-3-yl)-2-methylpropan-1-one oxime (as a mixture of cis- and trans-isomers), which was separated on an aluminum oxide column with hexane-dichloromethane-ethyl acetate as eluant to yield 0.3 g (cis-) and 0.325 g (trans-) isomers of 1-(2-isopropylpyrazolo[1,5-a]pyridin-3-yl)-2-methylpropan-1-one oxime. Compound 1012.

Provenance & Evidence