| 摘要 |
Compounds of the formula IV <IMAGE> IV wherein R is hydrogen or alkyl of 1 or 2 carbon atoms; wherein R1 is alkyl of 1 to 3 carbon atoms, inclusive; or <IMAGE> is a 2-cycloalkenylene ring of 5 or 6 carbon atoms; wherein R2 is hydrogen, methyl or ethyl; wherein R3 is hydrogen, fluoro, chloro, bromo, nitro and -CF3; and wherein Ar is phenyl, o-chlorophenyl, o-fluorophenyl, 2,6-difluorophenyl, and 2-pyridyl, are prepared by treating a hydrazino compound of the formula: <IMAGE> I wherein Ar and R3 are defined as above, with a dicarbonyl compound II: <IMAGE> II and cyclizing the resulting compound III to give the compound IV above.
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