1,4-Dihydropyridazine compounds, and their medicinal use

A compound of the formula I ##STR47## wherein R.sup.1 is a straight or branched alkyl radical with up to 6 carbon atoms optionally substituted by one substituent selected from fluoro, chloro or phenyl;

• or represents thienyl, furyl or phenyl, the phenyl optionally having 1 substituent from the group halogen, nitro, cyano, of hydroxyl,
• R.sup.2 represents phenyl, naphthyl, thienyl or furyl, the above mentioned phenyl optionally having 1 or 2 identical or different substituents selected from the group alkyl with 1 to 2 carbon atoms, alkoxy with 1 to 2 carbon atoms or halogen, or substituted by one of cyano, nitro, hydroxyl, trifluoromethyl or trifluoromethoxy;
• R.sup.3 is hydrogen or the group COOR.sup.6, wherein R.sup.6 is a straight-chain branched saturated or unsaturated aliphatic hydrocarbon radical having up to 6 carbon atoms, which is optionally interrupted in the chain by 1 oxygen atom and/or which is optionally substituted by hydroxyl, halogen, phenyl or phenoxy;
• or is cyclopentyl or cyclohexyl and
• R.sup.4 is alkyl with 1 to 4 carbon atoms, or fluoroalkyl with 1 or 2 carbon atoms, phenyl optionally substituted by nitro, or is thienyl or furyl.