| abstract |
1363735 Benzimidazolones FARBWERKE HOECHST AG 20 Oct 1971 [23 Oct 1970 24 June 1971] 48786/71 Heading C2C Compounds of general Formula (I) in which R 1 represents H or C 1-4 alkyl, and R 2 and R 3 (which may be the same or different) each represent H, halogen, or a C 1-4 alkyl, alkoxy or acyl group, or a hydroxy, carboxylic acid or sulphonic acid group, are prepared by reacting an o-phenylene diamine of general Formula (II) with urea in solution in water at 80-180‹ C. |