Investigation of the Effect of Power and Duration of Ultrasonic Irradiation on the Synthesis of Thiazoles.

Introduction: The effect of power and duration of ultrasonic irradiation on the synthesis of thiazoles via the Hantzsch reaction was investigated.

Methods: The reaction of phenacyl bromides with thioamides under ultrasonic irradiation afforded the target thiazoles in good yields.

Results: The results showed that high power and long irradiation time cause the decomposition of the reaction materials, and for this reaction, the irradiation power of 720 watts and a total duration of 4 minutes, wherein a pulsing function was performed in 50% of each second, were considered the most suitable irradiation properties for the synthesis of thiazoles through the Hantzsch reaction.

Nickel-Cobalt Salen Organometallic Complexes Encapsulated in Mesoporous NaA Nanozeolite for Electrocatalytic Quantification of Ascorbic Acid and Paracetamol.

Goal of current study was fabrication of novel voltammetric nanosensor for the synchronize quantification of ascorbic acid (AA) and paracetamol (PAR) by nickel-cobalt salen complexes encapsulated in the supercages of NaA nanozeolite modified carbon paste electrode (NiCoSalenA/CPE). For this purpose, NiCoSalenA nanocomposite was firstly prepared and characterized by various methods. Also, cyclic voltammetry (CV), choronoamperometry (CHA) and differential pulse voltammetry (DPV) were utilized to evaluate performance of the modified electrodes.

A review of syntheses of 1,5-disubstituted tetrazole derivatives.

This report provides a brief overview of the various representative literature procedures for the synthesis of 1,5-disubstituted tetrazoles (1,5-DSTs) and fused 1,5-disubstituted tetrazoles with more than 120 references. Most of the published methods for the synthesis of 1,5-DSTs include the use of nitriles, amides, thioamides, imidoyl chlorides, heterocumulenes, isocyanates, isothiocyanates, carbodiimides, ketenimines, ketones, amines, and alkenes as the starting materials. The transformation of 1- and 5-substituted tetrazoles into 1,5-DSTs is also covered in this report.

Synthesis and biological evaluation of coumarin derivatives as inhibitors of Mycobacterium bovis (BCG).

The coumarin compounds are an important class of biologically active molecules, which have attractive caught the attention of many organic and medicinal chemists, due to potential pharmaceutical implications and industrial applications. We herein report the one-pot procedure for the efficient synthesis of coumarin derivatives using commercially available substrates via isocyanide-based multicomponent condensation reactions. These compounds were evaluated for anti-mycobacterium activity against Mycobacterium bovis (Bacillus Calmette-Guerin).

Recent progress of isocyanide-based multicomponent reactions in Iran.

The aim of this review is to provide an overview of the contributions and recent advances made by Iranian scientists in the field of isocyanide-based reactions between 1999 and 2009. With over 100 publications during this period, Iranians are responsible for approximately 10% of all publications in the world involving isocyanide-based multicomponent reactions (IMCRs). Some important aspects of these IMCRs include the execution of reactions in green reaction mediums like water or ethanol, high atom economies, mild reaction conditions, high yields, and catalyst-free processes.

Novel one-pot three- and pseudo-five-component reactions: synthesis of functionalized benzo[g]- and dihydropyrano[2,3-g]chromene derivatives.

A novel and efficient method has been developed for the synthesis of highly functionalized benzo[g]- and dihydropyrano[2,3-g]chromene derivatives via addition and subsequently cyclization of 2-hydroxynaphthalene-1,4-dione or 2,5-dihydroxycyclohexa-2,5-diene-1,4-dione to the condensation product of an aldehyde with malononitrile in the presence of a catalytic amount of Et(3)N in CH(3)CN at ambient temperature. The procedures are very facile. The products can be obtained with simple filtration in high yields, and no more purification is needed.

A novel one-pot three-(in situ five-)component condensation reaction: an unexpected approach for the synthesis of tetrahydro-2,4-dioxo-1H-benzo[b][1,5]diazepine-3-yl-2-methylpropanamide derivatives.

A novel and efficient method has been developed for the synthesis of tetrahydro-2,4-dioxo-1H-benzo[b][1,5]diazepine-3-yl-2-methylpropanamide derivatives using an aromatic diamine, Meldrum's acid, and an isocyanide in CH(2)Cl(2) at ambient temperature in high yields without using any catalyst or activation. The procedure provides an alternative method for the synthesis of benzo[b][1,5]diazepine derivatives. These compounds have closely related ring systems such as triflubazam, clobazam, and 1,5-benzodiazepines, which have a broad spectrum of biological activities.

Synthesis of highly functionalized bis(4H-chromene) and 4H-benzo[g]chromene derivatives via an isocyanide-based pseudo-five-component reaction.

The reactive intermediates generated by the addition of alkyl, aryl, and alicyclic isocyanides to dialkyl acetylenedicarboxylates were trapped by 2,5-dihydroxycyclohexa-2,5-diene-1,4-dione or 2-hydroxynaphthalene-1,4-dione to produce highly functionalized bis(4H-chromene)- and 4H-benzo[g]chromene-3,4-dicarboxylate derivatives in fairly good yields in CH(3)CN at room temperature. These compounds are closely related to the ring systems pentalongin, dehydroherbarin, 1,3-disubstituted-3,4-dehydropyranonaphthoquinones, and 3-arylpyranonaphthoquinones, which have a broad spectrum of biological activity.

A novel method for the synthesis of substituted 3,4-dihydrocoumarin derivatives via isocyanide-based three-component reaction.

A new one-pot procedure for the efficient synthesis of novel 3,4-dihydrocoumarin derivatives using commercially available substituted 2-hydroxybenzaldehydes, Meldrum's acid, and isocyanides by a three-component condensation reaction in dichloromethane at room temperature without using any catalysts and activation was developed.

Meldrum's acid catalyzed reaction of tetracyanoethylene and aldehydes in water: a novel approach to arylidenemalononitrile.

Meldrum's acid catalyzed the reaction of tetracyanoethylene with aromatic, heteroaromatic, and conjugated aldehydes led to arylidenemalononitrile in water in good yields at 80 degrees C. The work-up of reactions is very simple and the crude products are sufficiently pure to be used without further purification. The procedure provides an alternative method for the synthesis of arylidenemalononitrile.

A simple and efficient approach to the synthesis of 4H-furo[3,4-b]pyrans via a three-component reaction of isocyanides.

A three-component reaction of an isocyanide, a dialkyl acetylenedicarboxylate, and tetronic acid in dichloromethane at room temperature afforded 4H-furo[3,4-b]pyran derivatives. These compounds are closely related with ring systems, TAN-2483B, TAN-2483A, and FD-211 which have a broad spectrum of biological activity.

Novel isocyanide-based four-component reaction: a facile synthesis of fully substituted 3,4-dihydrocoumarin derivatives.

A novel isocyanide-based four-component reaction between a 2-hydroxybenzaldehyde, Meldrum's acid, an isocyanide, and an aromatic or an aliphatic alcohol efficiently provide 3,4-dihydrocoumarin derivatives in good to excellent yields without using any catalyst or activation. The reaction can be carried out as a simple one-pot protocol at room temperature.