Pyridine → HCID 5281089, compound

Participants

Reaction Steps

20.4 Mmol (5.3 g) of 5-methoxy-4'-trifluoromethylvalerophenone (melting point 43°-44° C), 20.5 mmol (3.1 g) of 2-aminooxyethylaminedihydrochloride and 10 ml of pyridine were refluxed for 15 hours in 20 ml of absolute ethanol. After evaporating the pyridine and the ethanol in vacuo, the residue was dissolved in water. This solution was washed with petroleum ether and 10 ml of 50% sodium hydroxide solution were then added. Then three extractions with 40 ml of ether were carried out. The ether extract was washed successively with 20 ml of 5% sodium bicarbonate solution and 20 ml of water. After drying on sodium sulphate, the ether layer was evaporated in vacuo. Toluene was then evaporated another three times (to remove the pyridine) and the oil thus obtained was dissolved in 15 ml of absolute ethanol. An equimolar quantity of maleic acid was added to said solution and the solution was then heated until a clear solution was obtained. The ethanol was then removed in vacuo and the residue was crystallized from 10 ml of acetonitrile at +5° C. After sucking off and washing with cold acetonitrile, it was dried in air. The melting point of the resulting title compound was 120°-121.5° C.

Provenance & Evidence