Diphenyl carbonate → 2-Aminobenzimidazole

Participants

Reaction Steps

Melting point 100° C., with decomposition. IR(CHCl3) 1,562, 1,580, 1,602, 1,618, 1,665 and 1,725 cm-1. ##STR91## The starting material 3-methyl-2,4-dioxo-1,2,3,4-tetrahydro-s-triazino-[1,2-a]-benzimidazole is known from German Published Specification DOS 2,144,505 ##STR92## The starting material 3-phenyl-2,4-dioxo-1,2,3,4-tetrahydro-s-triazino-[1,2-a]-benzimidazole is known from German Published Specification DOS 2,144,505. ##STR93## The starting material 3-tetradecyl-2,4-dioxo-1,2,3,4-tetrahydro-s-triazino-[1,2-a]-benzimidazol (m.p. 193° C.) is obtained by reacting 1 -(benzimidazole-2-yl)-3-tetradecylurea and diphenylcarbonate. 1-(benzimidazole-2-yl)-3-tetradecylurea is formed by the reaction of 2-aminobenzimidazole and tetradecylisocyanate in xylene at 120° C. ##STR94## The starting material 3-cyclohexyl-2,4-dioxo-1,2,3,4-tetrahydro-s-triazino[1,2-a]-benzimidazole (m.p. 335° C.) is obtained from 1-(benzimidazole-2-yl)-3-cyclohexylurea and diphenylcarbonate. 1-(benzimidazole-2-yl)-3-cyclohexylurea is obtained from 2-aminobenzimidazole and cyclohexylisocyanate at about 120° C. in xylene. ##STR95## The starting material 3-(2-phenylethyl)-2,4-dioxo-1,2,3,4-tetrahydro-s-triazino-[1,2-a]-benzimidazole (m.p. 298° C.) is produced from diphenylcarbobate and 1-(benzimidazole-2-yl)-3-(2-phenylethyl)-urea. The latter is produced from N-benzimidazole-2-yl-carbamic acid phenyl ester and 2-phenylethylamine. ##STR96## The starting material 3-(ω-methylamino-carbonylpentyl)-2,4-dioxo-1,2,3,4-tetrahydro-s-triazino-[1,2-a]-benzimidazole (m.p. 268° C. destr.) is formed by boiling 3-(ω-methoxycarbonylpentyl)-2,4-dioxo-1,2,3,4-tetrahydro-s-triazino-[1,2-a]-benzimidazole (m.p. 221° C.) in a mixture of butanol and water with methylamine.

Provenance & Evidence