Hydrazinium chloride → 2,3,6,7-tetrahydro-5H-cyclopenta[d]pyridazine-1,4-dione

Participants

Reaction Steps

A solution of hydrazine hydrochloride (2.4 g, 22.8 mmol) and 1-cyclopentene-1,2-dicarboxylic anhydride (3.0 g, 21.7 mmol) in water (10 mL) is heated to reflux for 3 h. The reaction mixture is cooled down to room temperature and the precipitate is collected by filtration. The yellow solid is mixed with 15 mL 1N NaOH and stirred for 2 h, filtered and dried under vacuum to give 2,3,6,7-tetrahydro-5H-cyclopenta[d]pyridazine-1,4-dione (38) (2.2 g, 67%).

Provenance & Evidence