Synthesis and study of antiinflammatory and analgesic activity of 6-methyl(phenyl)-3-aroylmethylene-piperazin-2-ones

Abstract

Previously we have demonstrated that 3-phenacylmethylenepiperazin-2-ones possess antiinflammatory and analgesic properties in combination with low toxicity [1, 2]. In order to search for a relationship between the structure of piperazin-2-ones and their antiinflammatory and analgesic effects, it would be of interest to introduce a substituent in position 5 or 6 of the piperazinone cycle.For this purpose, we have studied reactions of the methyl esters of aroylpyruvic acids (I) with 1,2-diaminopropane (II) and 1,2-diaminophenylethane (III). Because compounds II and III are nonsymmewically substituted, the reactions may proceed in two pathways with the formation of isomeric piperazinones A and B: H R' N CH-C-R

(Het)aroylpyruvic acids and their derivatives as promising building blocks for organic synthesis

“…3,5 The piperazinone 84a is formed when the pyruvate 31a is treated with a large excess of ethylenediamine at 20 8C in a MeOH ± AcOH mixture, and the product 84b is produced on refluxing equimolar amounts of the reactants in methanol. Non-symmetric 1-methyl-and 1-phenyl-1,2-diaminoethanes have been shown 142 to react selectively with the APA esters 2 on refluxing in an ethanol ± acetic acid mixture to give the corresponding 6-methyl-or 6-phenyl-3-aroylmethylenepiperazin-2-one 85 as the only reaction product.…”

“…17 Antibacterial action has been discovered for a number of 1-phenyl-5-hetarylpyrazole-3-carboxylic acids 67. 23 3-Aroylmethylenepiperazin-2-ones 81 137,139,191 and their 1-methyl-and 1-phenyl-82 141,191 or 6-methyl-and 6-phenyl-substituted 85 142 derivatives show antiinflammatory, anticonvulsant and analgesic activities in combination with low toxicity. Antiinflammatory 94 and analgesic 91,94 effects of 3-(1-phenylazoaroylmethylene)-1,2,3,4-tetrahydroquinoxalin-2-ones 87 (X = N = NPh) have been reported.…”