Diisopropylamine → HCID 178434197, compound

Participants

Reaction Conditions

Reaction Steps

To an ice-cold solution of 13.9 ml of diisopropylamine in 50 ml of anhydrous tetrahydrofuran there was added, by syringe, 38 ml of 2.6 N butyllithium in hexane. The mixture was cooled to -78° C. and a solution of 4.5 grams of 1,5,6,7-tetrahydro-3-methyl-4H-indazol-4-one was added dropwise. The mixture was stirred at -78° C. for 30 minutes and a solution of 10 ml of ethyl formate in 30 ml of anhydrous tetrahydrofuran was added dropwise. When the addition was complete, the reaction was allowed to warm to 0° C. and it was quenched by the dropwise addition of water (200 ml). After the mixture was stirred vigorously for a few minutes, the two layers which formed were separated. The aqueous layer was washed with ethyl ether and then acidified to a pH of about 4 with 5 N hydrochloric acid. The slurry which formed was extracted several times with dichloromethane and the combined extracts were dried and concentrated under reduced pressure to give 1,5,6,7-tetrahydro-5-hydroxymethylene-3-methyl-4H-indazol-4-one as a clammy yellow semi-solid.

Provenance & Evidence