Potassium Nitrate → HCID 18975375, compound

Participants

Reaction Conditions

Reaction Steps

5H,10H-8--Nitroimidazo[1,2-a]indeno[1,2-e]-pyrazin-4-one may be prepared in the following way: 1 g of potassium nitrate is added over 10 minutes, at a temperature in the region of 5° C., to a solution of 2.6 g of 5H,10H-imidazo[1,2-a]indeno[1,2-e]pyrazin-4-one hydrochloride in 20 ml of concentrated sulphuric acid (d=1.83). The mixture is stirred for 30 minutes at the same temperature and for 3 hours at 25° C., then is poured onto 150 ml of ice-water. The crystals formed are isolated by filtration, washed with distilled water and then with acetone and dried under reduced pressure (1 mmHg; 0.13 kPa) at 80° C. 2.1 g of 8-nitro-5H,10H-imidazo[1,2-a]indeno[1,2-e]pyrazin-4-one are thus obtained, decomposing without melting above 300° C. [NMR spectrum: (200 MHz; DMSO-d6 ; δ in ppm): 4.23 (s, 2H: --CH2-- at 10); 7.68 and 8.12 (2 broad s, 1H each: --H of the imidazole); 8.07 (dd, J=8.5 Hz, 1H: --H6); 8.38 (dd, J=8.5 and 1.5 Hz, 1H: --H7; 8.50 (d, J=1.5 Hz, 1H: --H9); 12.64 (mult., 1H: --CONH--)].

Provenance & Evidence