Patent ID: 7880016

Claim:
A process for preparing a salt of an optionally substituted 4-(benzimidazol-2-ylmethylamino)-benzamidine of formula (I) with organic or inorganic acids, wherein R 1 denotes a C 1-6 -alkyl or C 3-7 -cycloalkyl group, R 2 denotes a C 1-6 -alkyl group, a C 3-7 -cycloalkyl group optionally substituted by a C 1-3 -alkyl group, while the C 1-3 -alkyl group may additionally be substituted by a carboxyl group, or denotes an R 21 NR 22 group, wherein R 21 denotes a C 1-6 alkyl group which may be substituted by a carboxy, C 1-6 alkoxycarbonyl, benzyloxycarbonyl, C 1-3 -alkylsulphonylaminocarbonyl, phenylsulphonylaminocarbonyl, trifluorosulphonylamino, trifluorosulphonylaminocarbonyl or 1H-tetrazolyl group, a C 2-4 -alkyl group substituted by a hydroxy, phenyl-C 1-3 -alkoxy, carboxy -C 1-3 -alkylamino, C 1-3 -alkoxycarbonyl-C 1-3 -alkylamino, N-(C 1-3 -alkyl)-carboxy -C 1-3 -alkylamino or N-(C 1-3 -alkyl)-C 1-3 -alkoxycarbonyl-C 1-3 -alkylamino group, while in the above-mentioned groups the carbon atom in the α position to the adjacent nitrogen atom cannot be substituted, or a piperidinyl group optionally substituted by a C 1-3 -alkyl group, and R 22 denotes a hydrogen atom, a C 1-6 -alkyl group, a C 3-7 -cycloalkyl group optionally substituted by a C 1-3 -alkyl group, or a C 3-6 -alkenyl or C 3-6 -alkynyl group, while the unsaturated moiety may not be linked directly to the nitrogen atom of the R 21 NR 22 group, a phenyl group optionally substituted by a fluorine, chlorine or bromine atom, by a C 1-3 -alkyl or C 1-3 -alkoxy group, or a benzyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, pyrazolyl, pyridinyl, pyrimidinyl, pyrazinyl, pyridazinyl, pyrrolyl, thienyl or imidazolyl group optionally substituted by a C 1-3 -alkyl group, or R 21 and R 22 together with the nitrogen atom between them denote a 5- to 7-membered cycloalkyleneimino group optionally substituted by a carboxy or C 1-4 -alkoxycarbonyl group, to which additionally a phenyl ring may be fused, and R 3 denotes a C 1-9 -alkoxycarbonyl, cyclohexyloxycarbonyl, phenyl -C 1-3 -alkoxycarbonyl, benzoyl, p-C 1-3- alkyl-benzoyl or pyridinoyl group, while the ethoxy moiety in the 2 position of the above-mentioned C 1-9 -alkoxycarbonyl group may additionally be substituted by a C 1-3 -alkylsulphonyl or 2-(C 1-3 -alkoxy)-ethyl group, comprising the steps of: (a) reacting phenyldiamine of formula (II) wherein R 1 and R 2 have the meanings given for formula (I), with 2-[4-(1,2,4-oxadiazol-5-on-3-yl)-phenylamino]-acetic acid to form a product of formula (III) wherein R 1 and R 2 have the meanings given for formula (I), (b) i) hydrogenating the product of formula (III); and ii) reacting the product of step (b)(i), without any prior isolation, with a compound of formula (IV), R 3 —X (IV), wherein R 3 of formula (IV) has the meaning given hereinbefore and X denotes a suitable leaving group; and iii) converting the product from step (b)(ii), without any prior isolation, into a physiologically acceptable salt.