摘要 |
The present invention relates to a process for preparation of amino substituted benzothiazole derivatives of formula (I), wherein R<1>, R<2> and R<3> are independently from each other hydrogen, lower alkyl, lower alkoxy or halogen; R<4> is hydrogen, lower alkyl, lower alkyloxy, halogen, or is a five or six membered non aromatic heterocyclyl group, unsubstituted or substituted by lower alkyl or an oxo-group, or is -NR<5>R<6> wherein R<5> and R<6> are independently from each other hydrogen, lower alkyl, -C(O)-lower alkyl, -(CH2)nO-lower alkyl or benzyl, opionally substituted by lower alkyl, or is an five or six membered heteroaryl group; R<1> and R<2> or R<2> and R<3> may form together with the corresponding carbon atoms a ring containing -O-CH2-O- or -CH=CH-CH=CH-; R is hydrogen or -C(O)R'; R' is a five or six membered non aromatic heterocyclyl group, five or six membered heteroaryl group or is aryl, which rings may be substituted by the groups, selected from lower alkyl, halogen-lower alkyl, lower alkoxy, cyano, nitro, -C(O)H, -C(O)OH or by pyrrolidin-1-yl-methyl; n is 1 to 4; and to their pharmaceutically acceptable salts, wherein the cyclization is carried out by the treatment of a compound of formula with sulphoxide/HBr/solvent to give the desired products of formula (I) for R is hydrogen (formula IA) and for R is -C(O)R' (formula IB). |