Patent ID: 7030130

Claim:
A compound of formula wherein R 1 represents cycloalkylmethyl with 3 to 6 carbon atoms; aryl; arylmethyl or heteroarymethyl, the aryl and heteroaryl group may be mono-, di- or tri-substituted with halogen, amino, hydroxy, nitro, trifluoromethyl, lower alkyloxy, lower alkylcarbonylamino, arylcarbonylamino, whereby these substituents may be the same or different; straight or branched chain lower alkylcarbonyl with up to 6 carbon atoms; cycloalkylcarbonyl with 3 to 6 carbon atoms; cycloalkylhydroxymethyl with 3 to 6 carbon atoms; arylcarbonyl, the aryl group may be mono-, di or tri-substituted with halogen, amino, lower alkyloxy, lower alkylcarbonylamino, arylcarbonylamino, whereby these substituents may be the same or different; arylhydroxymethyl, the aryl group may be mono-, di- or tri-substituted with halogen, amino, lower alkyloxy, lower alkylcarbonylamino, arylcarbonylamino, whereby these substituents may be the same or different; straight or branched chain lower alkenyl with 2 to 6 carbon atoms; hydroxy-lower alkyl with 1 to 6 carbon atoms; fluoro-lower alkyl with 1 to 6 carbon atoms; aryloxy-lower alkyl whereby the aryl group may be mono-, di- or tri-substituted with halogen, amino, lower alkyloxy, lower alkylcarbonylamino, arylcarbonylamino, whereby these substituents may be the same or different; arylthio-lower alkyl whereby the aryl group may be mono-, di- or tri-substituted with halogen, amino, lower alkyloxy, lower alkylcarbonylamino, arylcarbonylamino, whereby these substituents may be the same or different; arylamino-lower alkyl whereby the aryl group may be mono-, di- or tri-substituted with halogen, amino, lower alkyloxy, lower alkylcarbonylamino, arylcarbonylamino, whereby these substituents may be the same or different; lower alkenyloxy lower alkyl whereby the lower alkenyl group may contain 2 to 4 carbon atoms and the lower alkyl group may contain 1 or 2 carbon atoms; benzyloxy lower alkyl whereby the benzyl group may be mono-, di- or tri-substituted with halogen, amino, lower alkyloxy, lower alkylcarbonylamino, arylcarbonylamino, whereby these substituents may be the same or different; lower alkylamino lower alkyl whereby the lower alkyl groups may contain 1 to 3 carbon atoms; heterocyclylmethyl containing one to three hetero atoms which can be the same or different and which may be substituted with lower alkyl, halogen, amino, lower alkyloxy, hydroxy, lower alkylcarbonylamino, arylcarbonylamino and benzofused derivatives thereof, and wherein R 2 and R 3 independently represent hydrogen; lower alkyl with 1 to 3 carbon atoms; or together a lower alkylene group with 1 to 3 carbon atoms bridging the oxygen atoms and forming a five, six or seven membered ring; R 4 represents hydrogen; straight or branched chain lower alkyl with 1 to 4 carbon atoms; a pharmaceutically acceptable salt thereof; or N-oxide thereof.