Abstract: 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 ...