Process for the preparation of benzimidazole derivatives.

摘要

1. Process for preparing benzimidazole derivatives of general formula I see diagramm : EP0027646,P7,F1 wherein R represents hydrogen, halogen, C1-4 alkyl, C1-3 alkoxy or trifluoromethyl, R**1 represents amino or C1-4 alkoxycarbonylamino and R**2 represents an ionically bonded metal atom, an ionically or covalently bonded hydrogen atom, C1-6 alkyl, alkenyl or alkynyl each having up to 6 carbon atoms, or cyclohexyl, benzyl or 2-phenylethyl, and the salts thereof, characterised in that a compound of general formula II see diagramm : EP0027646,P7,F2 wherein R and R**1 are as hereinbefore defined, is converted, by treatment with a nucleophilic organic or inorganic base, into a compound of general formula III see diagramm : EP0027646,P7,F3 wherein R and R**1 are as hereinbefore defined and R**2' represents an ionically bonded metal atom or an ionically or covalently bonded hydrogen atom, which is optionally reacted with an alkylating agent of general formula IV R**2" -Q wherein R**2" represents C1-6 alkyl, alkenyl or alkynyl each having up to 6 carbon atoms, cyclohexyl, benzyl or 2-phenylethyl and Q represents hydroxy, halogen, 1/2 SO4 , 1/3 PO3 , 1/3 PO4 , SO3 C6 H5 or SO3 C6 H4 CH3 , in a manner known per se, and if desired the compound of general formula I thus obtained is converted into a salt thereof.