Formaldehyde → HCID 19844955, compound

Participants

Reaction Steps

59.4 g of 4,4'-difluoro-β-phenylpropiophenone, prepared in accordance with step (a), together with 39.2 g of dimethylamine hydrochloride and 14.4 g of paraformaldehyde are heated overnight under reflux. The reaction mixture is then concentrated by evaporation and the residue is taken up in 300 ml of water and is extracted with three 200 ml portions of ether. The combined ether extracts are washed twice with water and then twice with a saturated solution of NaCl, dried over Na2SO4 and filtered. The filtrate is concentrated, affording 1-(4-fluorophenyl)-2-(4-fluorobenzyl)-prop-2-en-1-one of the formula ##STR9## as a crude product which is immediately reacted further. The crude product is dissolved in 140 ml of ethanol and a solution of 18.8 g of hydrazine hydrate in 70 ml of methanol is added dropwise to this ethanolic solution. When the addition is complete, the reaction mixture is heated under reflux for three hours, cooled and then concentrated by rotary evaporation. The resultant residue is taken up in ether and the ethereal solution is washed twice with water and then twice with a saturated solution of NaCl, dried over Na2SO4 and filtered. The filtrate is concentrated by evaporation, thus affording the title compound of the formula ##STR10##

Provenance & Evidence