GB864131A - Benzimidazolyl-acetic acid derivatives - Google Patents

Abstract

The invention comprises 1-aminoalkyl-benzimidazolyl-(2)-acetamides of the formula: <FORM:0864131/IV (b)/1> and acid addition salts thereof, wherein A is a lower alkylene group, R represents a di-lower alkylamino group, R1 is a phenyl group optionally bearing halogen, lower alkyl or lower alkoxy substituents in the 3-and 4-positions and R2 is hydrogen or a nitro group (the word "lower" denoting groups of 1-5 carbon atoms). The compounds are prepared known methods such as (a) introducing the dialkylaminoalkyl group into the 1-position of the benzimidazole by reacting an a -benzimidazolyl-(2)-a -phenyl-acetamide with a reactive ester such as a halide or organic sulphonate, of an alcohol R1-A-OH wherein R1 is a dialkylamino group of a group which is subsequently converted thereto, such as a hydroxyl group which is converted by chlorination followed by reaction with a secondary amine; (b) subjection an aniline derivative bearing an ortho substituent Y-NH-, where Y is a dialkylaminoalkyl group or a group which is subsequently converted thereto such as a b -chlorethyl group, to ring closure with an a -carbamoyl-phenylacetic acid or a reactive functional derivative thereof; or (c) converting a substituent in the a -position of the benzyl radical of a 1-dialkylaminoalkyl-2-benzyl benzimidazole, for example a carboxyl, acid halide, acid ester or nitrile group into a carbamoyl group. Preferred products include a -[1-(b -diethylamino-ethyl)-benzimidazolyl-(2)]- a -phenyl- and a -p-chlorophenyl-acetamides and the corresponding 5-nitro-compounds. The products are used pharmaceutically (see Group VI) suitably in the form of acid addition salts such as the hydrohalide, sulphate, nitrate, phosphate, thiocyanate, acetate, propionate, oxalate, malonate, succinate, malate, methanesulphonate, ethanesulphonate, hydroxyethansulphonate, benzenesulphonate and toluenesulphonate.ALSO:Analgesic pharmaceutical preparations comprise 1 - aminoalkyl - benzimidazolyl - (2) - acetamides of the formula <FORM:0864131/VI/1> and acid addition salts thereof with inorganic or organic acids, e.g. hydrohalic, sulphuric, nitric, phosphoric, thiocyanic, acetic, propionic, oxalic, malinic, succinic, malic, methane-sulphonic, benzene sulphonic, hydroxyethane-sulphuric acids or with acids having therapeutic action (see Group IV (b)), wherein A is a lower alkylene group, R represents a di-loweralkyl-amino group, R1 is a phenyl group optionally bearing halogen, lower alkyl or lower alkoxy substituents in the 3- and 4-positions and R2 is hydrogen or a nitro group (the word "lower" denoting groups of 1-5 carbon atoms), in conjunction with a pharmaceutical organic or inorganic, solid or liquid excipient suitable for enteral or parenteral or topical application. The preparations may take the form of tablets, dragees, ointments, creams, solutions, suspensions or emulsions.