Hydrochloric Acid → 4-[4-[5-(2,6-Difluorophenyl)-4,5-dihydro-3-isoxazolyl]-2-thiazolyl]hexahydropyridazine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 1,2-diethyl 4-[4-[5-(2,6-difluorophenyl)-4,5-dihydro-3-isoxazolyl]-2-thiazolyl]tetrahydro-1,2-pyridazinedicarboxylate (i.e. the product of Step G) (4.09 g, 0.0083 mol) and potassium hydroxide (2.32 g, 0.0414 mol) in ethanol (50 mL) and water (5 mL) was heated at reflux for 20 h. The reaction mixture was cooled, acidified by the addition of concentrated hydrochloric acid, and then warmed to about 70° C. for 10 minutes. The reaction mixture was cooled, neutralised by the addition of sodium bicarbonate. The reaction mixture was concentrated under reduced pressure and the resulting matterial was extracted with diethyl ether (3×), dried over magnesium sulfate, filtered and concentrated under reduced pressure to a tan oil (2.99 g). The oil was adsorbed onto Celite® (diatomaceous filter aid), and then by purified by silica gel column chromatography (5% to 100% gradient of methanol in chloroform as eluant) to provide the title compound (1.275 g).

Herkunft & Nachweise