Sulfolane → Methyl 10,11-dihydrodibenzo[b,f][1,4]thiazepin-3-carboxylate 5,5-Dioxide

Participants

Reaction Steps

Suspend 6.7 gm. (20 mmole) of methyl 11-chlorodibenzo[b,f][1,4]thiazepin-3-carboxylate 5,5-dioxide in 60 ml. of sulfolane and stir under nitrogen at room temperature while adding 1.52 g. (40 mmole) of sodium borohydride in small portions. Control foaming, if desired, by adding small portions of dry ether. After 2 hours, pour the reaction mixture into 300 ml. of ice-water and 75 ml. of ether. Separate the precipitate by filtration, wash with water and dry in vacuo. Dissolve the precipitate in 175 ml. of boiling acetonitrile, filter and concentrate to 100 ml. Separate the precipitate to obtain the title product. (m.p. 236° C.)

Provenance & Evidence