Hydrogen Sulfide → 5,6,7,8-Tetrahydro-3-methyl-8-quinolinecarbothioamide

Participants

Reaction Conditions

Reaction Steps

A solution of 3-methyl-5,6,7,8-tetrahydroquinoline-8-carboxamide (27.9 g. 0.14 m) in dry pyridine (300 ml.), saturated with H2S gas, was treated with P2S5 (26 g., 0.14 m) and heated at reflux for 45 min. whilst maintaining a slow stream of H2S gas. The reaction mixture was evaporated to dryness in vacuo and cooled to 0° C, made alkaline with 10% sodium hydroxide and the solution extracted with chloroform (3 × 100 ml.). The combined extracts were washed with brine, dried and evaporated in vacuo. The residual oil was triturated with benzene and the solid filtered and recrystallised from benzene to give the title compound as pale yellow needles m.p. 149° (21.8 g., 87%). The hydrochloride was prepared as already described in Example 18 and isolated as colourless needles m.p. 219° C.

Provenance & Evidence