Methane → 10-benzamido-5H,10H-imidazo[1,2-a]-indeno[1,2-e]pyrazin-4-one

Participants

Reaction Conditions

Reaction Steps

1.7 g of benzoyl chloride are added over 1 minute to a solution of 3.1 g of 10-amino-5H,10H-imidazo[1,2-a]indeno[1,2-e]pyrazin-4-one hydrochloride in 200 ml of 0.1N sodium hydroxide. The mixture is stirred for 2 hours at a temperature in the region of 20° C. and the insoluble material is separated out by filtration, washed twice with 200 ml in total of distilled water and air-dried. The product obtained (3 g) is dissolved in 100 ml of dimethyl sulphoxide and, after addition of decolorizing charcoal, the solution is filtered. The filter is washed with 20 ml of dimethyl sulphoxide and the filtrate and the washings are then combined and 80 ml of distilled water are added at 20° C. The insoluble material is separated out by filtration, washed twice with 50 ml in total of distilled water and with 25 ml of acetone and then dried under reduced pressure (1 mmHg; 0.13 kPa) at 100° C. 1.75 g of 10-benzamido-5H,10H-imidazo[1,2-a]-indeno[1,2-e]pyrazin-4-one are thus obtained, decomposing without melting at 300° C. [N.M.R. spectrum: (200 MHz; DMSO d6 ; δ in ppm): 6.40 (d, J=8.5 Hz, 1H: CH--N); from 7.30 to 7.70 (mt, 8H: --H6, --H7, --H8, --H9, aromatic --H para and meta to the --CO--NH-- and --H of the imidazole); from 7.80 to 8.00 (mt, 3H: aromatic --H ortho to the --CO--NH-- and --H of the imidazole); 9.14 (d, J=8.5 Hz, 1H: --NH--); 12.55 (cplx, 1H: --CO--NH-- of the ring)].

Provenance & Evidence