Patent ID: 7087761

Claim:
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 5 are independently from each other hydrogen, lower alkyl, —C(O)-lower alkyl, —(CH 2 ) n O-lower alkyl or benzyl, optionally substituted by lower alkyl, or is a 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—CH 2 —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; or a pharmaceutically acceptable salt thereof, 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)