Sodium Acetate → 1,2-Diethyl 4-[4-[5-(2,6-difluorophenyl)-4,5-dihydro-3-isoxazolyl]-2-thiazolyl]tetrahydro-1,2-pyridazinedicarboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of 1,2-diethyl 4-(aminothioxomethyl)tetrahydro-1,2-pyridazinedicarboxylate (i.e. the product of Step F) (2.58 g, 0.0089 mol) and 2-bromo-1-(4,5-dihydro-5-(2,6-difluorophenyl)-3-isoxazolyl)ethanone (i.e the product of Step C) (2.63 g, 0.0086 mol) in methanol (20 mL) were carefully heated to 35° C. No exotherm was observed and the temperature was raised to between 45 to 50° C. and held at this temperature for 1 h. The reaction mixture was neutralised with aqueous sodium acetate (0.73 g in about 20 mL water). The reaction mixture was extracted with diethyl ether (3×), dried magnesium sulfate, filtered, and concentrated under reduced pressure to provide the title compound (4.18 g), which was used without purification.

Provenance & Evidence