Abstract: The invention relates to new thiazolo[4,5-c]quinoline derivatives of the general Formula I ##STR1## and acid addition salts thereof, a process for the preparation of the same and pharmaceutical compositions comprising the said compounds.The substituent definition of the general Formula I is as follows:R stands for hydrogen; a straight or branched chained alkyl group having 2-5 carbon atoms optionally substituted by one or more halogen atom(s); phenyl or phenyl-(lower alkyl) optionally bearing one or more substituent(s) on the phenyl ring;R.sup.1 and R.sup.2 are identical or different and stand for hydrogen, halogen or lower alkyl).The compounds of the general Formula I possess valuable central nervous depressive properties.

Abstract: It has been found that 2-methyl-thiazolo[4,5-c]quinoline and pharmaceutically acceptable acid addition salts and hydrates thereof possess valuable central nervous depressive properties being different from those of benzodiazepines. The invention relates to pharmaceutical compositions comprising as active ingredient 2-methyl-thiazolo[4,5-c]quinoline of the Formula I ##STR1## or a pharmaceutically acceptable acid addition salt or hydrate thereof.