N-Di:ethylamino-ethyl 2-methoxy 5-methyl:sulphonyl benzamide prepn. - by reacting methyl iodide with 5-sulphinyl-salicylic acid to form methyl 2-methoxy-5-methyl:sulphonyl-benzoate and reacting with amine

摘要

Prepn. of N-(diethylamino-ethyl)- 2-methoxy-5 -methylsulphonyl-benzamide (I) and its acid addition salts comprises (a) reaction of methyl iodide with 5-sulphinyl-salicylic acid (IV) in DMF, in the presence of an alkaline agent, to form methyl 2-methoxy-5-methylsulphonyl- benzoate (II) free from the homologous sulphinic ester (III); (b) reaction of (II) with a stoichiometric amt. of N-(diethylamino) -ethylamine in water at 80-100 deg.C. or without solvents at 40-70 deg.C., in both cases under nitrogen to form (I). (II) may be saponified to form 2-methoxy-5 -methylsulphonyl-benzoic acid (V). (I) is a known pharmaceutical. (II) is obtained in excellent yields from the relatively cheap (IV), without traces of (III). The reaction of (II) to give (I) is described in FR2305176, but necessitates the use of an alcohol solvent e.g. butanol; the present process gives excellent yields without solvents or in aqueous soln. (V) is a useful intermediate (e.g. for (I)) which is obtained in good yields.