Pyridine → 10H-phenothiazine-2-carbothioamide

Participants

Reaction Conditions

Reaction Steps

A reaction mixture comprising 3.4 g (14 mmoles) of 10H-phenothiazine-2-carboxamide (J. Org. Chem. 1961, 26, 1138-1143) and 3.4 g (8.4 mmoles) of Lawesson reagent in solution in 40 ml of 1,4-dioxane to which 20 ml of pyridine has been added is heated to 110° C. for 1 h 30. The brown solution is then concentrated under vacuum and the residue is diluted in 200 ml of AcOEt and 100 ml of H2O. After stirring and decantation, the organic phase is washed successively with 100 ml of a 1N aqueous solution of HCl and 100 ml of salt water. After drying over sodium sulphate, filtration and evaporation of the solvent under vacuum, an orange powder is obtained. This powder is washed with Et2O, the filtrate is eliminated, and extracted with acetone. The acetone filtrate is then concentrated under vacuum and the evaporation residue is then purified using a silica column (eluent: Heptane/AcOEt: 1/1 to 4/6). Orange powder. Melting point: 208-209° C.

Provenance & Evidence