Hydrochloric Acid → 1-cyclohexyl--cyanoquinoxaline-2,3(1H,4H)-dione

Participants

Reaction Conditions

Reaction Steps

A solution of 1.2 g (4.9 mmol N-Cyclohexyl-4-cyano-2-nitroaniline 100 ml ethyl acetate was hydrogenated at 40 psi by using 5% Pd/C (100 mg) as a catalyst. The reaction mixture was filtered and 2.0 g (20 mmol) dry triethylamine was added. A solution of 2.7 g (20 mmol) ethyl oxalyl chloride in 20 ml ethyl acetate was added dropwise and the reaction mixture was stirred for 3 h. The reaction mixture was filtered and evaporated in vacuo to give an oil. A mixture of the oil, 20 ml ethanol and 70 ml 0.5 N hydrochloric acid was refluxed for 1 h. After cooling to 25° C. the precipitate was filtered off and washed with water to give 0.33 g (25 %) 1-cyclohexyl--cyanoquinoxaline-2,3(1H,4H)-dione. M.p.(DSC): decomp. 1H-NMR (DMSO-d6): 12.0 )1H, broad s), 8.0-7.4 (3H, m), 4.4 (1H, m), 2.7-0.7 (10H, m). IR (KBr): 2450, 1700 cm -1.

Provenance & Evidence