Hydrochloric Acid → 2-nitromethylenetetrahydro-2H-1,3-thiazine

Participants

Reaction Conditions

Reaction Steps

Into 40 ml of methanol were added 5.5 g of 1-amino-3-propanethiol and 2.4 g of caustic soda, followed by stirring, to be completely dissolved therein. Then, the mixture was cooled to 0° C. While stirring the solution, a solution of 2.8 g of 2,2-dichloronitroethylene diluted in 10 ml of methanol was added dropwise slowly over 15 minutes, and the reaction was carried out for one hour. The reaction was exothermic and the liquid temperature was maintained at lower than 10° C. (about 8° C.) After the reaction, the reaction mixture was neutralized to pH 7 with 6 N aqueous hydrochloric acid, and then with addition of 30 ml of water, extraction with 50 ml of chloroform was repeated four times. The extracts were concentrated to give 2.24 g of tetrahydro-2-(nitromethylene)-1,3-thiazine (yield: 70.0%).

Provenance & Evidence