2-Naphthalenecarboxamide → naphthalene-2-carbothioamide

Participants

Reaction Steps

To a solution of the above amide (10.0 g, 58 mmol) in dry tetrahydrofuran (250 ml) was added [2,4-bis-(4-methoxyphenyl)-1,3-dithia-2,4-diphosphenate-2,4-disulfide] (Lawesson's reagent) (16.5 g, 41 mmol) and the resulting mixture was stirred at room temperature for 48 h. The volatiles were evaporated in vacuo and the residue was dissolved in ethyl acetate (100 ml) and filtered through silicagel (100 ml) using ethyl acetate as eluent. The solvent was evaporated in vacuo and to the residue was added a mixture of ethyl acetate (25 ml) and heptane (25 ml). The precipitate was filtered off and washed with heptane (40 ml), dried in vacuo at 50° C. which afforded 9.0 g (83%) of naphthalene-2-carbothioic acid amide as a solid.

Provenance & Evidence