2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 8-(3-Sulfamoyl-phenylamino)-thiazolo[4,5-h]quinazoline-2-carboxylic acid ethyl ester

Participants

Reaction Steps

A suspension of 8-(3-Sulfamoyl-phenylamino)-4,5-dihydro-thiazolo[4,5-h]quinazoline-2-carboxylic acid ethyl ester (609 mg, 1.41 mmol) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (480 mg, 2.12 mmol) in anhydrous 1,4-dioxane (30 mL) was refluxed under nitrogen for 2 hours. The reaction mixture was cooled down to room temperature and the DDQ residues were filtered. The mother liquor was concentrated in vacuo and the resulting crude residue was triturated in a mixture of EtOAc, MeOH and DCM. The resulting solid was filtered to afford 523 mg (86% yield) of the title compound as a yellow solid. MS (ES+) 430, (ES−) 428. δH (d6 DMSO) 1.42 (3H, t), 4.51 (2H, q), 7.37 (2H, s), 7.52 (1H, d), 7.60 (1H, t), 8.09 (1H, d), 8.14 (2H, s), 8.70 (1H, s), 9.55 (1H, s), 10.59 (1H, s).

Provenance & Evidence