Phosphorus oxychloride → 4,8-Dichloroimidazo[1,2-a]quinoxaline

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Reaction Steps

By reaction of 8-chloroimidazo[1,2-a]quinoxaline-4(5H)-one (example 17) with POCl3, following a procedure that is similar to that described in example 1, there is obtained 4,8-dichloroimidazo[1,2-a]quinoxaline that is subsequently reacted with cyclopentylamine according to the method described in example 3, thereby obtaining 4-cyclopentylamino-8-chloroimidazo[1,2-a]quinoxaline. m.p. (DSC)=140.1° C.(onset); IR (KBr): 3401, 2955, 1554 cm-1 ; 1H-NMR (CDCl3): δ7.8 (1H,d, J=2 Hz), 7.7÷7.2 (4H,m), 6.15 (1H,d), 4.6 (1H,m), 2.3÷2.05 (4H,m), 2.05÷1.3 (4H,m); UV (EtOH): λmax =229, 245, 289, 301, 326, 340 nm. Elementary analysis for C15H15ClN4 (m.w. 286.76): calcd. C 62.83, H 5.27, N 19.54%; found C 63.04, H 5.36, N 19.64%.

Provenance & Evidence