Synthesis of Some3-Chloro-2,3-dimethyl-1-phenylpyrazolidin-5-one

S.AL.Gawady, Moayed; M. Saied, Shakir; Y. Raoof, Moneera

doi:10.32894/kujss.2013.79699

Synthesis of Some3-Chloro-2,3-dimethyl-1-phenylpyrazolidin-5-one

Authors

10.32894/kujss.2013.79699

Abstract

(E)-3-Chloro-4-arylidene-2,3-dimethyl-1-phenylpyrazolidin-5-one 1(a-c) which were used as synthon for synthesis of all target compounds were prepared from the reaction of 3-chloro-2,3-dimethyl-1-phenylpyrazolidin-5-one(Chlorophenazone)with aromatic aldehydes by 1,4-Michael addition .
4-Aryl-3-chloro-2,3-dimethyl-1-phenyl-2,3-dihydro-1H-pyrazolo[3,4-d]pyrimidine-6(5H)- one2(a-c) and -6(5H)-thiones 2(d-f)were prepared in low yields(40-50%) by the reaction of 1 (a-c) with urea or thiourea respectively in refluxing ethanol. The refluxing of 1(a-c)with hydrazine hydrate in presence of pyridine afford 3-chloro-4-aryl-2,3-dimethyl-1-phenyl-1,2,3,5-tetrahydropyrazolo[3,4-c]pyrazole 3(a-c).
Also, 2-benzyl-4-spiro-5-chloro-1,5- dimethyl-2-phenylpyrazolidin-3-one
(4) was obtained via epoxidation of 1(a) by hydrogen peroxide in presence of anhydrous sodium carbonate, the reaction of this spiro compound with hydrazine hydrate gave 3-chloro-2,3-dimethyl-1,4-diphenyl-1,2,3,3a -tetrahydropyrazolo[3,4-c]pyrazole (5). Finally, the authentic samples of pyrazole (5) was prepared by the oxidation of 3(a) with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) .
The structures of these compounds were confirmed by their physical properties in addition to the IR and UV Spectra.

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