| 摘要 |
The title compds. I [R1= H, lower alkyl, alkylcarbonyl, diamino lower alkyl; R2= H, lower alkyl; R3,R4,R5= H, lower alkyl, lower alkyloxy, halo, OH, CN, NO2, amino, mono- or di-(lower alkyl) amino, aminocarbonyl, lower alkyl carbonylamino, lower alkyl carbonyl, lower alkylcarbonyloxy, etc.! were prepd. Thus, 94 parts of ethyl 4,4- dimethoxy-3-(phenylmethoxy)-1-piperidine carboxylate were refluxed with 2300 parts of 1% H2SO4 for 2 hr. and 30 min. After cooling, the resulting mixt. was washed with dichloro methane three times to give 64.9 parts of ethyl 4-oxo-3(phenylmethoxy)-1-piperidine carboxylate.
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