Efficient One-Pot Synthesis of Alkyl 2-(Dialkylamino)-4-phenylthiazole-5-carboxylates and Single-Crystal X-Ray Structure of Methyl 2-(Diisopropylamino)-4-phenylthiazole-5-carboxylate

An acid-based DES as a novel catalyst for the synthesis of pyranopyrimidines

Deep eutectic solvents have countless advantages over normal solvents, and in addition to complying with the principles of green chemistry, depending on their nature, they can also act as catalysts. The use of deep eutectic solvents as acid catalysts has several advantages such as non-toxicity, a catalytic effect similar to or higher than the acid itself, and the possibility of recovery and reuse without significant loss of activity. In this project, A novel deep eutectic solvent (MTPPBr-PCAT-DES) was prepared from a one-to-one mole ratio of methyltriphenyl-phosphonium bromide (MTPPBr) and 3,4-dihydroxybenzoic acid (PCAT = protocatechuic acid) and characterized by various techniques such as FT-IR, TGA/DTA, densitometer, eutectic point, 1H NMR, 13C NMR and 31P NMR. Then, it was used as a novel and capable catalyst for the synthesis of pyranopyrimidines from the multicomponent condensation reaction of barbituric acid, 4-hydroxycoumarin, and aromatic aldehydes in mild conditions, short reaction times, and high yields.

Synthesis and Crystal Structures of Some New 2-(Diphenylamino)-4,5-Disubstituted Thiazole Derivatives

The reactions of diphenylamine and benzoyl isothiocyanates with phenacyl bromide or methyl 2-bromoacetate in the presence of triethylamine yield 2,4,5-trisubstituted thiazole derivatives. The molecular structures of [2-(diphenylamino)-4-phenylthiazol-5-yl]( o-tolyl) methanone and methyl 4-(4-chlorophenyl)-2-(diphenylamino)thiazole-5-carboxylate have been fully determined by means of single crystal X-ray diffraction methods.

Synthesis of 1-Azadienes by a Three-Component Reaction between Isocyanides, Esters and 3-Hydroxy-2-Methyl-4H-Pyran-4-One

The 1: 1 reactive intermediate generated by the addition of alkyl isocyanides to dialkyl acetylenedicarboxylates was trapped by 3-hydroxy-2-methyl-4 H -pyran-4-one as OH-acid in water to yield highly functionalised 1-azadienes.

One-pot chemoenzymatic multicomponent synthesis of thiazole derivatives

A novel chemoenzymatic one-pot multicomponent synthesis of thiazole derivatives was developed. A series of thiazole derivatives were synthesized with high yields up to 94% under mild enzyme-catalyzed conditions. The blank and control experiments reveal that trypsin from porcine pancreas (PPT) displayed great catalytic activity to promote this reaction and showed a wide tolerance range towards different substrate amines. This trypsin-catalyzed multicomponent conversion method provides a novel strategy to synthesize thiazole derivatives and expands the application of enzymes in organic synthesis.