摘要：

Some new chlorosubstituted 4-aroyl/alkoylpyrazolines 5a,b and 4-aroyl/alkoylpyrazoles 7a,b have been synthesized by condensation of 1-(2'-hydroxy-3'-5'-dichlorophenyl)-3-aryl/alkyl-1-3-propanedione 3a,b and valeraldehyde by Baker-Venkatraman transformation of corresponding aroyl/alkoyloxyacetophenones. Aroyl/Alkoyloxyacetophenones 2a,b undergo intramolecular Claisen condensation to form 1-(2'-hydroxy-3'-5'-dichlorophenyl)-3-aryl/alkyl-1,3-propanediones 3a,b which on treatment with aliphatic aldehyde in ethanol containing little piperidine forms 3-aroyl/alkoylchromanones 4a,b. From these 3-aroyl/alkoylchromanones 4a,b 4-aroyl/alkoylpyrazolines 5a,b are synthesized 3-Aroyl/Alkoylchromanones 4a,b are converted into 3-aroyl/alkoylchromones 6a,b The 3-aroyl/alkoylchromones 6a,b on treatment with Ph NHNH(2) HCl in dioxane containing small amount of piperidine furnish 4-aroyl/alkoylpyrazoles 7a,v. The structures of the newly synthesized chlorosubstituted 4-aroyl/alkoylpyrazolines 5a,b and 4-aroyl/alkoylpyrazoles 7a,b have been elucidated on the basis of spectral analysis and their homogeneity has been established by TLC.

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