Dichloromethane → Tienocarbine

Participants

Reaction Conditions

Reaction Steps

15,75 g of 5-hydrazino-3-methylbenzothiophene hydrochloride are suspended in 500 ml of water, a layer of methylene chloride is introduced under the suspension and 10.5 g of 1-methyl-4-piperidone are added at about 0° C. The mixture is then adjusted to pH 9.5 with N NaOH and is stirred for 30 minutes. The organic phase is separated off and washed with saturated NaCl solution, dried and mixed with 500 ml of ethylene glycol and the methylene chloride is distilled off under a vacuum of 12 mm. Some of the glycol is then distilled off under 0.01 mm and at 100° C. and the concentrated solution is heated to 200° C. (bath temperature) in an N2 atmosphere for 1/2 hour. The crystals which precipitate on cooling the mixture are filtered off, washed and recrystallised from ethyl acetate. Melting point: 224°-227° C.

Provenance & Evidence