New derivatives of 6-phenylcomanic acid

Abstract

Ethyl 6 phenylcomanic acid with hydrazine hydrate and hydroxylamine gives 4 oxo 6 phenyl 4H pyran 2 carbohydrazide and 4 oxo 6 phenyl 4H pyran 2 carbohydroxamic acid, whereas 6 phenylcomanic acid with ammonia in aqueous DMSO gives 4 hydroxy 6 phenylpicolinic acid, converted further to its ethyl ester and hydrazide. The reaction of 6 phenylcomanic acid with phenylhydrazine gives rise to 3 (1,5 diphenyl 1H pyrazol 3 yl) 2 (2 phenylhydrazono)propionic acid, which by the Fischer reaction was converted to 3 (1,5 diphenyl 1H pyrazol 3 yl) 1H indole 2 carboxylic acid.

2-Aryl-6-Polyfluoroalkyl-4-Pyrones as Promising RF-Building-Blocks: Synthesis and Application for Construction of Fluorinated Azaheterocycles

“…Phenylhydrazine reacted with pyrone 5a regioselectively attacking with the amino group at the C-2 and C-4 positions to give pyrazole 9 . The structure of pyrazole 9 was assigned based on NMR spectra according to the literature data [ 16 , 34 ].…”

“…Recently, methods for the preparation of pyrones based on the cyclization of acetylenyl-1,3-diketones have been actively developed [ 29 , 30 , 31 , 32 , 33 ], which allows the switchable preparation of 4-pyrones or furanones. Similar approach is the use of dibromo derivatives, which can react as synthetic equivalents of acetylenyl-1,3-diketones and undergo dehydrobromination reactions under basic conditions [ 34 , 35 , 36 , 37 ]. This method was applied for the preparation of 2-aryl-4-pyrones bearing the methyl and carboethoxy substituents.…”

6-(Trifluoromethyl)-2H-pyran-2-ones: Promising CF3-bearing conjugated cyclic diene and electrophilic building-blocks

“…(18-45%) [11], and indicated that the reaction of 5 with diethyl malonate, probably, proceeds via intermediates 7 or/and 8, 9 [11,12]. is important to note that the reaction of 13 with HN 3 proceeded selectively at the carbonyl group of cyclopentadienone fragment and followed by the selective migration of the aryl substituent.…”

“…Similarly, the highly regio-and stereoselective solvent-free inverse electron-demand DielsAlder reaction of 11a with 2,3-dihydrofuran gave bicyclic lactone 74 (61%) (Scheme 20) [11]. A c c e p t e d M a n u s c r i p t 24 Trifluoromethylated 3-amino-2-pyridones prepared by hydrolysis of 82 were used in catalytic hydrogenation and in the synthesis of CF 3 -containing mimetics of ornithine and thalidomide [22].…”

“…Pyrones 11 were decarbethoxylated in high yields to 4-aryl-6-CF 3 -2H-pyran-2-ones 12 by refluxing in aqueous acetic acid with H 2 SO 4 (64-90%) (Scheme 3)[11].Subsequent transformations of pyrones 11 lead to the formation of their fused derivatives. Reaction of 11 with sulfuric acid (110-125 o C for 10 min) gave the corresponding highly reactive fused indanopyrones 13 as a result of intramolecular Friedel-Crafts acylation (41-65%) (Scheme 4) [11, 12].…”