Abstract

COMPARATIVE LOGARITHMIC PARTITION COEFFICIENT STUDY OF SYNTHESIZED FIVE MEMBERED LACTAM DERIVATIVES FOR LIPOPHILICITY

Kinsuk Sarker, Rutvi Patel, Clive Dadida and Prof. Dr. Dhrubo Jyoti Sen*

Abstract

Five membered heterocyclic moiety (pyrazolone) has been synthesized by reacting between phenyl hydrazine and hydrazine with β-keto ester (ethyl acetoacetate) by condensation reaction to get the desired moiety which on alkaline permanganate oxidation gives the corresponding carboxylic acid derivatives in two series. The four compounds (I & II) of 1st series and (II & IV) of 2nd series were characterized for structural framework. The logP profile of all four compounds is as follows: Reagents: [Highest] Phenyl hydrazine > Ethyl acetoacetate > Hydrazine hydrate [Lowest]. Compounds: [Highest] I (5-methyl-2-phenyl-1,2-dihydro-3H-pyrazol- 3-one) > II (5-oxo-1-phenyl-2,5-dihydro-1H-pyrazole-3-carboxylic acid) > III (5-methyl-1,2-dihydro-3H-pyrazol-3-one) > IV (5-oxo-2,5- dihydro-1H-pyrazole-3-carboxylic acid) > [Lowest]. This logarithm of partition coefficient of all the said items is totally dependent on the polarity and solubility of the matters. The hydrophobicity and hydrophilicity of all synthesized four compounds depend on logP values due to the substituted functional groups of pyrazolone ring. Phenyl/Methyl/Carboxylic acid the three main chromophore groups change their logP parameters as well as surface tension. logP profile: I (5-methyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one)>II (5-oxo-1-phenyl-2,5-dihydro-1Hpyrazole- 3-carboxylic acid). III (5-methyl-1,2-dihydro-3H-pyrazol-3-one)>IV (5-oxo-2,5-dihydro-1H-pyrazole-3- carboxylic acid) Surface tension profile: I (5-methyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one)

Keywords: Pyrazolone, Pyrazolone carboxylic acid, logP, KMnO4/KOH oxidation, H2O2 oxidation, Polarity, Partition coefficient, Surface tension.