Sodium Hydroxide → HCID 57285833, compound

Participants

Reaction Steps

The process is performed as in Example 3 for the preparation of 10-(2-carboxybenzylidene)-5H,10H-imidazo[1,2-a]indeno[1,2-e]pyrazin-4-one but starting with 5 g of 5H,10H-imidazo[1,2-a]indeno[1,2-e]pyrazin-4-one, 100 ml of dimethyl sulphoxide, 4.04 g of 3-methoxycarbonylbenzaldehyde and 1.6 g of 80% sodium hydride. After treatment of the reaction mixture with 100 ml of water and 10 ml of acetic acid, the suspension obtained is filtered; the insoluble product is washed with water, air-dried and then triturated with 80 ml of dimethylformamide, filtered off and dried. The yellow solid obtained (1 g) is suspended in 100 ml of water and, after addition of 25 ml of 0.1N sodium hydroxide, the solution is filtered and acidified with 2.5 ml of 1N hydrochloric acid. The precipitate formed is washed with water, triturated with 50 ml of methanol and dried at 60° C. under vacuum (1 mmHg; 0.13 kPa). 0.8 g of 10-(3-carboxybenzylidene)-5H,10H-imidazo[1,2-a]indeno[1,2-e]pyrazin-4-one is obtained in the form of a yellow solid melting above 260° C., which product is converted into the disodium salt of formula C21 H11N3O3Na2 (Analysis, % calculated C 63.17, H: 2.78, N: 10.52, O: 12.02, Na : 11.51, % found C: 62.9, H: 2.6, N: 10.2).

Provenance & Evidence