Lawesson's reagent → HCID 18726777, compound

Participants

Reaction Steps

2,4-Bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulphide (Lawesson's reagent) (19.5 g, 48.2 mmol) was added to a solution of 6,7-dichloro-2,3-dimethoxy-5-methoxyacetamidoquinoxaline (27 g, 78 mmol) in tetrahydrofuran (480 mL) and the mixture was stirred for 18 hours at room temperature, then evaporated under reduced pressure. The residue was purified by flash chromatography on silica gel, by gradient elution using hexane:dichloromethane (1:1 changing to 1:4, by volume) as the eluent to give 6,7-dichloro-2,3-dimethoxy-5-methoxythioacetamidoquinoxaline (29.1 g, >100%) as a white solid, mp 198-200° C., containing a minor impurity.

Provenance & Evidence