The Nature of the Firm Oxford

The present invention concerns compounds of Formula I wherein R1 is hydrogen, lower alkyl, aralkyl; R2 is hydrogen, lower alkyl, lower alkoxy, halogen, trifluoromethyl, cyano, nitro, and the like; R3 is lower alkyl; R4 ¦ -CNO2 ¦ R5 (where R4 and R5 are lower alkyl), R6 ¦ -C(CO2R7)2 (where R6 is hydrogen, lower alkyl, aryl, acetamido and R7 is lower alkyl), (WHERE R8 and R9 are hydrogen or lower alkyl), -CH(SO2C6H5)2, C6H5 ¦ -CR10 ¦ C6H5 (where R10 is hydrogen, CN, acyl), OOR11 PARALLEL -P ANGLE . OR12 (where R11 and R12 are lower alkyl), -SO2C6H5, -CONH2, -CO2R13(where R13 is lower alkyl), SR14 PARALLEL -S-C-N ANGLE R15 (R14 and R15 are lower alkyl).