Acetic Acid → Methyl 4-(4-oxo-1,4-dihydroindeno[1,2-c]pyrazol-3-yl)benzoate

Participants

Reaction Steps

A mixture of methyl 4-(1,4-dihydroindeno[1,2-c]pyrazol-3-yl)benzoate (6.3 g, Example 7), sodium bismuthate (31 g), glacial acetic acid (180 ml) and water (60 ml) was boiled under reflux for about 3.5 hours. A further amount of sodium bismuthate (33 g) was added and the mixture boiled under reflux for about 24 hours, then cooled. The pH of the reaction mixture was adjusted to 8-9 by addition of saturated sodium bicarbonate solution. The reaction mixture was filtered through a celite pad and the residue solid washed with ethyl acetate. The organic layer was separated, dried, filtered and evaporated to give a brown solid. The solid was boiled up in methanol (50 ml), cooled and the solid was filtered off, then dried to give methyl 4-(4-oxo-1,4-dihydroindeno[1,2-c]pyrazol-3-yl)benzoate, m.p. dec. 235° C.

Provenance & Evidence