Sulfuric acid magnesium salt (1:1) → 3-(4-Chlorophenyl)-2-isopropyl-7H-pyrano[2,3-e]indazol-4-one

Participants

Reaction Conditions

Reaction Steps

To a suspension of 2,4,6-trimethylbenzenesulfonic acid 3-(4-chlorophenyl)-8-formyl-2-isopropyl-4-oxo-4H-chromen-7-yl ester (391 mg, 0.745 mmol), magnesium sulphate (450 mg, 3.72 mmol) and ammonium acetate (230 mg, 2.98 mmol) in ethanol (15 ml) in a 20 ml microwave tube is added hydrazine hydrate (0.93 ml, 2.98 mmol). The tube is sealed and heated at 145° C. for ca. 80 min. The mixture is cooled to room temperature, and the volatiles are evaporated under reduced pressure. The residue is dissolved in dry pyridine (14 ml), the solution is transferred to a 20 ml microwave tube, the tube is sealed, and the mixture is heated at 190° C. for 100 min. The mixture is cooled and evaporated to dryness. The residue is purified by chromatography on silica gel using cyclohexane/ethyl acetate (6:1) as eluant.

Provenance & Evidence