Facile synthesis of 3,4-dihydropyrimidin-2(1H)-ones and -thiones and indeno[1,2-d]pyrimidines catalyzed byp-dodecylbenzenesulfonic acid

12‐Tungstosilicic Acid H4[W12SiO40] Over Natural Bentonite as a Heterogeneous Catalyst for the Synthesis of 3,4‐dihydropyrimidin‐2(1H)‐Ones

“…This method furnished products in poor yield in the case of aliphatic and substituted aromatics aldehydes . Due to their important medicinal activities, several improved protocols have been reported in the presence of Bronsted and Lewis acids . Despite their excellent catalytic activity, severe problems associated with them including harsh reaction condition, difficulty in separation, high cost, recycling and recovery of catalyst are a major concern and especially some environmental considerations.…”

One pot synthesis of 3, 4-dihydropyrimidine-2(1H)-thiones using orange peel powder under ultrasonic irradiation

“…Development of green chemical processes using less hazardous catalysts has become a primary goal in synthetic organic chemistry [1]. Multi-component reactions are of increasing importance in organic and medicinal chemistry [2]. They are for the synthesis of various heterocyclic compounds in drug discovery processes [3].…”

Succinic Acid As a Green and Bio-Based Catalyst assisted solvent-free one-pot Biginelli synthesis of biologically active 3,4-dihydropyrimidin-2-(1H)-ones/thiones derivatives

“…Recently, numerous protocols for the preparation of these compounds that is including various catalysts have been reported calcium fluoride (Chitra et al, 2009), copper(II)sulfamate (Liu et al, 2009), baker's yeast , hydrotalcite (Lal et al, 2012), hexaaquaaluminium (III) tetrafluoroborate (Litvic et al, 2010), TBAB (Ahmad et al, 2009), copper (II) tetrafluoroborate (Kamal et al, 2007), Copper (II) acetate (Khodja et al, 2014), [Btto][p-TSA] (Zhang et al, 2015), triethylammonium acetate (Attri et al, 2017), p-dodecyl-benzenesulfonic acid (Aswin et al, 2014) and TMSPTPOSA (Rao Jetti et al, 2017). Some of the limitations of these methodologies are low yields, toxic organic solvents and catalyst, harsh reaction conditions and expensive materials.…”