Solid support synthesis of 2,4-disubstituted thiazoles and aminothiazoles

Thiocyanation and 2-Amino-1,3-thiazole Formation in Water Using Recoverable and Reusable Glycosylated Resorcin[4]arene Cavitands

A family of three spatially directional resorcin[4]arene cavitand glycoconjugates (RCGs) have been applied as efficient recoverable and reusable inverse phase transfer catalysts for eco- and environmentally friendly thiocyanation and 2-amino-1,3-thiazole formation reactions in water. The results show that RCGs (1 mol %) were capable of hosting and catalyzing various water-insoluble bromo/thiocyanato substrates in water without the use of any co-organic solvents. The recoverability and reusability of RCG catalytic systems, that is, RCG1 and RCG3, were also examined upon a simple extraction of the desired products using DCM or ethyl acetate, followed by subjecting the recovered aqueous solution containing the RCG catalysts to the next reaction cycles.

Discovery of Novel Piperidinylthiazole Derivatives As Broad-Spectrum Fungicidal Candidates

Oxathiapiprolin is one of the best active fungicides discovered for oomycetes control. To develop a fungicide candidate with a broad spectrum of activity, 22 new piperidinylthiazole derivatives were designed and synthesized. Compound 5l showed the best activity against Pseudoperonospora cubensis (Berk. et Curt.) Rostov and Phytophthora infestans in vivo with 100% and 80% of inhibition, respectively, at 1 mg/L, and 72.87% of field efficacy against P. cubensis at 1 g ai/667 m² validated these results. Compound 5i exhibited a broad spectrum of excellent activity against Sclerotinia sclerotiorum with EC₅₀ = 0.30 mg/L (>10 times more active than oxathiapiprolin and azoxystrobin in vitro), good activity against Botrytis cinerea, Cercospora arachidicola, and Gibberella zeae with EC₅₀ of 14.54, 5.57, and 14.03 mg/L in vitro and against P. cubensis and P. infestans with 60% and 30% inhibition rates, respectively, at 1 mg/L in vivo. Mode of action studies by RNA sequencing analysis discovered oxysterol-binding protein (OSBP), chitin synthase (CHS1), and (1,3)-β-glucan synthase (FKS2) as the potent target of 5i against S. sclerotiorum. Quenching studies validated that OSBP was the same target of both 5i and oxathiapiprolin; it was quenched by both of them. Our studies discovered isothiazole-containing piperidinylthiazole as an OSBP target-based novel lead for fungicide development.

Synthesis of aminothiazoles: polymer-supported approaches

Aminothiazoles and their derivatives are of immense biological importance and have been consistently synthesizedviavarious methods.

Synthesis and Single Crystal Structures of Substituted-1,3-Selenazol-2-amines

The synthesis and X-ray single crystal structures of a series of new 4-substituted-1,3-selenazol-2-amines is reported. The efficient preparation of these compounds was carried out by two-component cyclization of the selenoureas with equimolar amounts of α-haloketones. The selenoureas were obtained from the reaction of Woollins’ reagent with cyanamides, followed by hydrolysis with water. All new compounds have been characterized by IR spectroscopy, multi-NMR (¹H, ¹³C, ⁷⁷Se) spectroscopy, accurate mass measurement and single crystal X-ray structure analysis.

Copper-Catalyzed Coupling of Oxime Acetates with Isothiocyanates: A Strategy for 2-Aminothiazoles

A new strategy for 2-aminothiazoles is developed via the copper-catalyzed coupling of oxime acetates with isothiocyanates. Various 4-substituted and 4,5-disubstituted 2-aminothiazoles were formed smoothly under mild reaction conditions. This process involved copper-catalyzed N-O bond cleavage, activation of vinyl sp(2) C-H bonds, and C-S/C-N bond formations. It is noteworthy that the oxime acetates were used not only as a substrate but also as a single oxidant.

Synthesis, anti-bacterial and anti-fungal activities of some novel Schiff bases containing 2,4-disubstituted thiazole ring

A series of arylidene-2-(4-(4-methoxy/bromophenyl) thiazol-2-yl) hydrazines (4a-z) and 1-(4-(4-methoxy/bromophenyl) thiazol-2-yl)-2-cyclohexylidene/cyclopentylidene hydrazines (5a-b/6a-b) were synthesized, characterized and screened for their antimicrobial activities. The structures of synthesized compounds were established by spectroscopic (FT-IR, (1)H NMR, (13)C NMR, Mass) and elemental analyses. Both the anti-bacterial and anti-fungal activities with MIC values of compounds were evaluated. The results of anti-bacterial screening reveal that among all the compounds screened eight compounds showed moderate to good anti-bacterial activity while ten of the newly synthesized compounds displayed good to excellent anti-fungal activity. Among the tested compounds, the most effective compounds with MIC value in the range of 6.25-25 microg/ml are 4a, 4n, 4z, 5a, 5b, 6a and 6b against three fungal strains viz. Candida albicans, Cryptococcus neoformans and Aspergillus flavus.

Design and synthesis of quinolin-2(1H)-one derivatives as potent CDK5 inhibitors

Cyclin-dependent kinase 5 (CDK5) is a serine/threonine protein kinase and its deregulation is implicated in a number of neurodegenerative disorders such as Alzheimer's disease, amyotrophic lateral sclerosis, and ischemic stroke. Using active site homology modeling between CDK5 and CDK2, we explored several different chemical series of potent CDK5 inhibitors. In this report, we describe the design, synthesis, and CDK5 inhibitory activities of quinolin-2(1H)-one derivatives.

What Can Be Done with the Acetyl Group of Aryl-1-Ethanones?

Literature data on utilization of acetyl group of aryl-1-ethanones (acetophenones) for the synthesis of organic compounds is generalized. Different approaches of preparation of aromatic compounds by chemical transformations of methyl as well as keto- group of titled compounds are systematized. Examples of the synthesis of organic compounds based on products of primary transformations of aryl-1-ethanones are considered.