Process for producing optically active benzo[b]thiophen-5-yl derivatives

Prodn.of an optically active benzo(b)thiophen-5-yl dialkylamino-ethoxy-ethanol deriv., of formula (VIA), (VIB) or their salts, comprising: (a) inoculating a supersatd. soln. of a dioxolo of formula (I) with seed crystals of the optically active dioxolo (IIA) or (IIB), depending on whether (VIA) or (VIB) is the objective, in the presence of a racemisation catalyst, to crystallise optically active (IIA) or (IIB) preferentially; (b) subjecting to alcoholysis or hydrolysis in presence of an acid catalyst; (c) protecting the free OH gp. to give (IIIA) or (IIIB); (d) reducing to diol deriv. (IVA) or (IVB); (e) reacting with a dialkylaminoethyl halide of formula (V); and (f) removal of the OH protecting gp., if desired, is new. In the formulae, R2 = H or a protecting gp.; R4,R5 = 1-6C alkyl; R2a = a protecting gp.; R3 = H or a protecting gp.; and BT = benzo(b)thiophen-5-yl; and X = a removable gp.. Specifically claimed are cpds. (-)-1-(Benzo(b)thiophenyl -5-yl)-2-(2- (N,N-diethylamino) ethoxy)ethanol; and (-) or (+) 2,2-dimethyl-(benzo(b)thiophen-5-yl)- 1,3-dioxolan-4-one. e en se t²k zp sobu v²roby opticky aktivn ch forem benzo[b]thiofen-5-ylderiv t obecn ho vzorce 6a nebo 6b a jejich sol , kde R.sup.2.n. p°edstavuje atom vod ku nebo chr nic skupinu hydroxylov skupiny a R.sup.4.n. a R.sup.5.n., kter jsou stejn nebo r zn , p°edstavuj alkylskupiny s 1 a 6 atomy uhl ku, reakc slou eniny obecn ho vzorce 4a nebo 4b, kde R.sup.2a.n. p°edstavuje chr nic skupinu hydroxyskupiny, se slou eninou obecn ho vzorce 5 nebo jej sol , kde R.sup.4.n. a R.sup.5.n. maj v² e uveden² v²znam a X p°edstavuje atom halogenu, alkylsulfonyloxyskupinu s 1 a 6 atomy uhl ku nebo arylsulfonyloxyskupinu, za p° tomnosti deacidifika n ho inidla a potom se pop° pad od t p chr nic skupina hydroxylov skupiny. Slou eniny obecn ho vzorce 6a a 6b zlep uj mozkovou funkci.\ Disclosed is a process for producing optically active forms of benzo[b]thiophen-5-yl derivatives of the general formula 6a or 6b or a salt thereof, wherein Re2 represents a hydrogen atom or a hydroxyl protecting group and Re4 and Re5, which may be the same or different, represent alkyl groups having 1 to 6 carbon atoms, by reacting the compound 4a or 4b, wherein Re2a represents a hydroxyl protecting group with the compound of the general formula 5 or with a salt thereof, wherein Re4 and Re5 are as specified above and X represents a halogen atom, an alkylsulfonyloxy group in the presence of a de-acidifying agent and subsequently the hyd