CeCl₃.7H₂O-SiO₂ Catalyzed Ultrasonicated Solvent-Free Synthesis of Carbamoyl/Carbamothioyl Phosphonates and Antimicrobial Activity Evaluation

Abstract

Running head: CeCl 3 .7H 2 O-SiO 2 catalysed solvent-free synthesis for P-C=(O,S) derivatives ABSTRACT An expeditious and green method has been developed for the synthesis of a series of P-C bond derivatives, diethyl substituted phenylcarbamoylphosphonates 6(a-e)/ phenylcarbamothioylphosphonates 7(a-f) in high yields via simple addition reaction of isocyanates/isothiocyanates with diethyl phosphite in the presence of silica supported Lewis acid catalyst, SiO 2 -CeCl 3 .7H 2 O under solvent-free and sonication conditions. The advantages of this method are high yields, avoiding of harmful solvents, operational simplicity, shorter reactiontime, and recoverability and recyclability of the catalyst. Antimicrobial activity was assayed for the title compounds, whereas, the compounds 6c, 7b and 7e against bacteria, and 6a, 7b, 7c and 7e against fungi exhibited potential growth of inhibition.

Phosphonate Derivatives of Paracetamol and Valproic Acid

“…There are few descriptions of biological testing of arylcarbamoyl‐phosphonates like compound 3 in the literature. The scaffold has been examined as antimicrobials, [18] Src SH2 domain ligands, [19] anti‐tumor agents [20] and human thyroid hormone agonists [21] . A recent paper published after this work was completed revealed that N ‐(4‐chlorophenylcarbamoyl)phosphonic acid possessed weak antimicrobial activity as well as some analgesic activity in multiple animal pain models [22] .…”

Synthesis of Carbamoylphosphates from Isocyanates Catalyzed by Rare-Earth-Metal Alkyl Complexes with a Silicon-Linked Diarylamido Ligand

“…9 Raju et al developed the silica-supported Lewis acid catalyst SiO 2 -CeCl 3 •7H 2 O to synthesize CPOs via the addition of diethyl phosphite to aromatic isocyanates under heating or ultrasonication conditions. 10 Challenges still exist despite these recent advances, such as high catalyst loading, low yields of the desired products, long reaction times, limited scope of isocyanates, and harsh conditions. Therefore, the development of highly efficient catalysts for the preparation of CPOs under mild conditions is still strongly required.…”

“…Kaboudin and co-workers found that 0.1 equiv of anhydrous calcium chloride as a Lewis base catalyst can promote the addition reaction to prepare CPOs in moderate yields (≤65%) . Raju et al developed the silica-supported Lewis acid catalyst SiO 2 -CeCl 3 ·7H 2 O to synthesize CPOs via the addition of diethyl phosphite to aromatic isocyanates under heating or ultrasonication conditions . Challenges still exist despite these recent advances, such as high catalyst loading, low yields of the desired products, long reaction times, limited scope of isocyanates, and harsh conditions.…”

A Facile One-Pot Synthesis of Novel 1,2,4-Triazolo[4,3-a]Pyridine Derivatives Containing the Trifluoromethyl Moiety Using Microwave Irradiation

“…In synthetic chemistry, green methods are attracting interest because of their environmental benefits. 1 Such methods include catalyst free, 2 supercritical fluids, 3 water-phase reactions, 4 ionic liquids, 5 solvent-free reactions, 6 metal-free 7 and ultrasound 8 or microwaves irradiation. 9 Nitrogen-containing heterocycles have also proved attractive andthey have been widely used in the medicinal, agricultural and industrial fields.…”