Catechol → 1,3-benzodioxole-2-thione

Participants

Reaction Steps

To 200 ml of aqueous sodium hydroxide (16.00 g, 0.400 mol) at 5° was added catechol (22.00 g, 0.200 mole). The resulting dark green solution was stirred magnetically and maintained at 5°-10° while thiophosgene (17 ml, 25.5 g, 0.22 mol) was added dropwise over 2 hours. The green color of the solution was discharged during the addition and an orange-brown precipitate formed. The mixture was filtered through a Buchner funnel into a saturated solution of aqueous sodium hydroxide to destroy any residual thiophosgene. The solid thus collected on the funnel was washed with 1.5 l of water and dried to give 27.41 (90 percent) of the crude 1,3-benzodioxole-2-thione (I): mp 151°-153° (sealed capillary; lit. mp 154°, 158°-158.5°). Sublimation twice at 150° (1 atm) gave white needles in 81 percent overall yield (lit. 25 percent): mp 158°-159.5° sealed capillary).

Provenance & Evidence