反应详情

2-Chloro-5-chlorosulfonylbenzoic acid (25.5 g.) is added in small portions over a 5 minute period with cooling to a solution of 1,2,5,6-tetrahydropyridine (25.0 g.) in 200 ml. of water. After stirring at room temperature for a half hour, the reaction mixture is acidified with concentrated hydrochloric acid. The crystalline precipitate is filtered off and dissolved in 75 ml. of methylene chloride and 10 ml. of ether. After concentration to 50 ml., hexane is added to turbidity, affording crystals, m.p. 180°-182° C.

1. filtrationThe crystalline precipitate is filtered off
2. dissolutiondissolved in 75 ml
3. concentrationAfter concentration to 50 ml
4. addition, hexane is added to turbidity
5. customaffording crystals, m.p. 180°-182° C.