a simple and mild method for tetrahydropyranylation of alcohols is reported at room temperature using a catalytic amount of 3-methylimidazolinium hydrogensulfate([hmim]hso4) as a green, efficient and reusable catalyst. using solvent-free conditions, non-toxic and inexpensive materials, modest and clean work-up, short reaction times and high yields of the products are the advantages of this method.

4-dodecylbenzenesulfonic acid (dbsa) has been shown to be an efficient, mild, green, stable and chemoselective brønsted acid catalyst for the synthesis of 1, 1-diacetates (acylals) of aldehydes under solvent-free conditions. the mild condition, eco-friendly, excellent yields, short reaction times and using an easily available, inexpensive and reusable catalyst are important features of this met...

A new, facile, cost effective, and eco-friendly protocol is reported for the synthesis of 2,3-dihydroquinazoline-4-(1H)-ones exploring tannic acid as a novel, inexpensive, andbiodegradable catalyst. A variety of dihydroquinazolins were prepared from aromatic aldehydesand anthranilamide using catalytic amount of tannic acid under solvent free conditions.Operational simplicity, high yield, and hi...

An effective one-pot synthesis of dihydropyrimidinonoes in solvent free conditions using CuCl2 as an inexpensive and readily available reagent through Biginelli condensation reaction of aldehyde derivatives, 1,3-dicarbonyl compounds and urea is described. Excellent yields, short reaction times for formation of the products and simple work-up are attractive features of this green prot...

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background and purpose: active learning, combined with computer-assisted instruction, can enhance medical students’ performance and learning. this article is an attempt to introduce a new web-based approach to information technology instruction for medical students. methods: eight topics were selected to be instructed in web-based workshops. phpbb forum was used for web-based collaborative lear...

online commerce, will become increasingly important as businesses realize the value of physically exchanging information goods (Chen & Sherrell, 2001). As a communication medium, the World Wide Web (WWW) provides an inexpensive new method for interacting with customers. A company’s Web presence also helps enhance credibility, gather feedback, improve customer service, and streamline business pr...

A convenient and highly efficient procedure for the synthesis of 3,4-dihydropyrimidin-2-(1H)-one/thione derivatives via one-pot three-component Biginelli condensation of arylaldehydes,urea/thiourea and ethyl/methyl acetoacetate in the presence of Zn(SO4)2.7H2Oas anefficient, readily and inexpensive catalyst under solvent-free conditions have been studied. Thisprotocol ha...

A simple and mild method for tetrahydropyranylation of alcohols is reported at room temperature using a catalytic amount of 3-methylimidazolinium hydrogensulfate([Hmim]HSO4) as a green, efficient and reusable catalyst. Using solvent-free conditions, non-toxic and inexpensive materials, modest and clean work-up, short reaction times and high yields of the products are the advantages o...

An effective one-pot synthesis of dihydropyrimidinonoes in solvent free conditions using CuCl2 as an inexpensive and readily available reagent through Biginelli condensation reaction of aldehyde derivatives, 1,3-dicarbonyl compounds and urea is described. Excellent yields, short reaction times for formation of the products and simple work-up are attractive features of this green protocol.