PYRANO-HETEROCYCLES,PROCESS FOR PREPARING THEM AND MEDICAMENTS CONTAINING THESE COMPOUNDS

Pyrano-heterocycles of the formula in which R1 represent hydrogen or an alkyl radical containing up to 4 carbon atoms; R2 represents hydrogen or an alkyl, alkoxy or haloalkyl radical each having up to 3 carbon atoms, or halogen; or R1 and R2 together form an ethylene or propylene group, and R3 and R4, independently of each other, are hydrogen or alkyl or alkoxy radicals each of which groups containing up to 3 carbon atoms, which may be unsubstituted or substituted totally or partially with halogen atoms, halogen or alkoxycarbonyl having up to 3 carbon atoms in the alkyl group and R5 represents a nitro group or hydrogen, their physiologically tolerated salts, processes for preparing these compounds and medicaments containing these compounds.