反应详情

The procedure is carried out as in Example 23, but starting with 1.1 g of bromine in 3.5 ml of acetic acid, 1.6 g of 7-trifluoromethoxy-3,4-dihydro -1H-quinoxalin-2-one and 1.54 g of potassium thiocyanate in 20 ml of acetic acid. The product obtained (1.8 g) is purified by chromatography on a silica gel column, eluting with a mixture of dichloromethane and methanol (99-1 by volume). 0.3 g of 2-imino-8-trifluoromethoxy -2H,4H-thiazolo[3,4,5-de]quinoxalin-5(6H)-one is thus obtained in the form of a yellow solid melting at 255° C. [Analysis C10H6F3N3O2S, % calculated C: 41.53, H: 2.09, F: 19.71, N: 14.53, O: 11.06, S: 11.09, % found C: 41.00, H: 1.7, F: 19.2, N: 14.50, S: 11.6].

1. customThe product obtained (1.8 g)
2. customis purified by chromatography on a silica gel column
3. washeluting with a mixture of dichloromethane and methanol (99-1 by volume)