Synthesis and some reactions of 4‐(ethoxycarbonyl)‐1,5‐diphenyl‐1H‐pyrazole‐3‐carboxylic acid

Abstract

1,5‐Diphenyl‐1H‐pyrazole‐3,4‐dicarboxylic acid‐4‐ethyl ester 2, obtained from the 4‐ethoxycarbonyl‐5‐phenyl‐2,3‐furandione 1 and N‐benzylidene‐N′‐phenyl hydrazine, was converted via reactions of its acid chloride 3 with various alcohols or N‐nucleophiles into the corresponding ester 5 or amide derivatives 6, respectively. In addition, 2 was decarboxylated to give ethyl 1,5‐diphenylpyrazole‐4‐carboxylate 4. Nitrile 7 derivative of 2 was also obtained by dehydration of 6a in a mixture of SOCl2 and DMF. While cyclocondensation reaction of 2 with hydrazine hydrate leads to the formation of pyrazolo[3,4‐d]pyridazine‐4,7‐dione 8, the reaction of 3 with anhydrous hydrazine provided a new bis pyrazole derivative 9.

The Synthesis and Reactions of Novel Pyrazole Derivatives by 4-phenylcarbonyl-5-phenyl-2,3-dihydro-2,3-furandione Reacted with Some Hydrazones

“…The by-products formed during this stage are removed by treatment of the raw product with diethyl ether. The reaction pathway from 4-benzoyl-5-phenyl-2,3-furandione 1 to pyrazole acid 2 is outlined briefly in scheme 2 and the compounds 2a and 2b were obtained according to the reported method [9,14] and the structures are in agreement with the reported data.…”

“…The 4,5-disubstituted 2,3-furandiones in furandione derivatives which are extremely versatile synthons in heterocyclic chemistry are remarkable starting materials due to the fact that many heterocyclic compounds can be obtained from their high reactivity properties. They shows the ability to enter carbonyl, lacton and a,b-unsaturated carbonyl and thermolysis reactions depending on the reaction conditions and structures of the nucleophiles [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Practical synthetic methods, mechanism of the reactions as well as semi-empirical and ab initio calculations on the interaction of 4-benzoyl-5-phenyl-2,3dihydro-2,3-furandione (1) with some ureas, semicarbazones, thioureas and anilides have been reported recently [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] The reactions of 2,3-furandiones with various phenylhydrazones and phenylhydrazine leads to pyrazole-3-carboxylic acid and pyridazinones [4,9,[19][20][21].…”

“…More continued attention on the pyridazines has been received for improving medicinal drugs in relation with for blood pressure control like hydralazine, which has been used for many years in the remedy of essential hypertension [30,31]. In continuation to our previous efforts [13,14], the nucleophilic and cycloaddition reactions between various N-nucleophiles and carbonyls with 4-benzoyl-5-phenyl-2,3-furandione which is novel bicyclic oxalyl compound were investigated, and synthesized. The new compounds shows their characterization studies and routes of synthesis.…”

Synthesis and Some Reactions of Pyrazole-3-carboxylic acid Having Trifluoromethyl Unit

“…A plethora of research worldwide has highlighted the importance of pyrazole derivatives. In particular, the synthesis of pyrazole possessing tetrasubstituted compounds from a reaction between 4-benzoyl-5-phenyl-2,3furandione 1 and various hydrazines or hydrazones has been recently reported (Şener et al, 2007;Akçamur et al, 1997). The compound, 4-benzoyl-5-phenyl-2,3-furandione 1, yields pyrazole-3-carboxylic acid and pyridazinone derivatives when reacted with hydrazine derivatives (Mengeş and Bildirici, 2017).…”

Synthesis and characterization of some pyrazole derivatives of 1,5‐diphenyl‐1H‐pyrazole‐3,4‐dicarboxylic acid

“…Pyrazole‐3‐carboxylic acid derivatives in general are well‐known nitrogen‐containing heterocyclic compounds, and various procedures have been developed for their syntheses [26–31]. In the literature, there is not much research related to the reactions of derivatives of 1,5‐diphenyl‐1 H ‐pyrazole‐3,4‐dicarboxylic acids although a number of new derivatives of pyrazoles some of which have bicyclic structure were synthesized [26–29].…”