Glycerol assisted eco-friendly strategy for the facile synthesis of 4,4′-(arylmethylene)bis(3-methyl-1H-pyrazol-5-ols) and 2-aryl-2,3-dihydroquinazolin-4(1H)-ones under catalyst-free conditions

Pyrazolone-type compounds: synthesis andin silicoassessment of antiviral potential against key viral proteins of SARS-CoV-2

“…Generally, the literature on these particular types of compounds is relatively scarce, and the research is mainly focused on the development of novel eco-friendly synthetic methods employing various catalysts, mostly ionic liquids and nanoparticles. [45][46][47][48][49][50][51][52] Following such a trend, the synthesis of pyrazolone analogues a-t was accomplished in the reactions of 5-methyl-2,4-dihydro-3H-pyrazol-3-one with different aromatic aldehydes in the presence of diethanolamine as a catalyst, and in ethanol and under reux. To optimise reaction conditions, the model reaction between benzaldehyde and 5-methyl-2,4-dihydro-3Hpyrazol-3-one was investigated in the presence of various catalysts and solvents (Table 1).…”

“…To our knowledge, these new compounds were not obtained by previously reported methods, while the other compounds are known. 50,[56][57][58][59][60] The products were obtained from good to excellent yield, except derivatives m, q, and r which were isolated in 31-45% yields (Table 2).…”

2,3-Dihydroquinazolin-4(1H)-one as a privileged scaffold in drug design

“…On the contrary, a simple and environmentally benign procedure, without any catalyst, lengthened the reaction time to hours, although producing similar yield. [184][185][186][187][188][189][190][191][192] The one-pot three-component reaction was also efficiently performed under solvent-free conditions in the presence of heterogeneous catalysts using conventional heating or MWI. The absence of catalyst again afforded 74-97% yield but in longer reaction times (1-6 h).…”

Efficient Preparation of Potassium Arylmethylene-4-(1H-Pyrazol-5-ol)-4′-(1H-Pyrazol-5-Olate) Derivatives via a Four-Component Reaction

“…[18][19][20][21][22][23][24][25][26][27] In recent decades, multicomponent reactions as an efficient synthetic method have attracted considerable attention, because complex products are formed in a one-pot reaction and diversity can be simply attained from relatively simple starting materials. Recently, one-pot multicomponent reactions of aromatic aldehydes, ethyl acetoacetate [28][29][30][31][32] or dimethyl but-2-ynedioate, 33,34 and phenylhydrazine/hydrazine hydrate also were used to form 4,4′-(arylmethylene)-bis(1Hpyrazol-5-ol) derivatives in the presence of various catalysts or promoters. To the best of our knowledge, no example using a four-component reaction of phenylhydrazine, dialkyl but-2-ynedioates, substituted benzaldehydes and basic potassium sources to directly construct the 4,4′-(arylmethylene)bis(1Hpyrazol-5-ol) potassium salts have been reported.…”