| abstract |
A process is described for making 2-aminomethyl-1,4-diaminobenzene, or a physiologically compatible salt of 2-aminomethyl-1,4-diaminobenzene, of formula (I):wherein n is a number from 0 to 3 and HX represents an inorganic or organic salt. In this process 2-(N-acylaminomethyl)-4-nitrophenol is first reacted with a halogen acetamide to form 2-(2-N-acylaminomethyl-4-nitrophenoxy)acetamide, which is then converted to 2-(N-acylaminomethyl)-4-nitroaniline. Subsequently the 2-(N-acylaminomethyl)4-nitroaniline is reduced to form 1,4-diamino-2-(N-acylaminomethyl)benzene, which is then deacylated by adding hydrochloric acid in a sufficient amount so that 1,4-diamino-2-aminomethylbenzene trihydrochloride is formed. Then the trichloride is converted to the free base form, 1,4-diamino-2-aminomethylbenzene, or to another salt of 1,4-diamino-2-amino-methylbenzene when n<> 0 with the proviso that if n=3 HX is not hydrochloric acid. Compositions and methods for dyeing keratin fibers using the compounds of formula I are also described. |