Hydrogen Bromide → 6-Bromo-6-isothiocyanatoquinoxaline

Participants

Reaction Steps

The crude hydrobromide product described above (4.27 g, 14.0 mmol) was dissolved in 60 ml of water; thiophosgene (Aldrich, 1.28 ml, 16.8 mmol) was added in small portions with vigorous stirring. After 2 hours, the red color of the solution was discharged. The solid formed was filtered off and washed thoroughly with water. After drying in vacuo at 25° C., 3.38 g of brick red crystals were obtained, m.p. 157-8° C., representing a yield of 90%. A portion of this material was further purified by column chromatography to give white crystals, m.p. 157-8° C. Using various analytical procedures, these crystals were determined to be 5-bromo-6-isothiocyanatoquinoxaline.

Provenance & Evidence