Potassium Acetate → Ethyl 1-methyl-8-(methylthio)-4,5-dihydro-1H-pyrazolo[4,3-h]quinazoline-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

9 g (69 mmol) of ethyl-6-[(dimethylamino)methylene]-1-methyl-7-oxo-4,5,6,7-tetrahydro-1H-indazole-3-carboxylate were dissolved in 350 mL of anhydrous dimethylformamide and 13.4 g of anhydrous potassium acetate (138 mmol) and 19.18 g (69 mmol) of methylisothiourea sulfate were added. The mixture was maintained at 90° C. under stirring for 8 hours. The solvent was then evaporated, the residue redissolved with dichloromethane and washed with water. The organic layer was dried over Na2SO4 and evaporated. The crude was finally triturated with diethyl ether and collected by filtration to give 15.5 g (74% yield) of the title compound.

Provenance & Evidence