ChemInform Abstract: Environmentally Benign Approach to Imidazole‐2‐thiones.

Abstract

Imidazole derivatives R 0190Environmentally Benign Approach to Imidazole-2-thiones. -A microwave-promoted synthesis of substituted imidazolethiones (III) (12 examples) from benzoin (I) and substituted thioureas (II) is achieved under solvent-free conditions . -(KIDWAI*, M.; KUKREJA, S.; RASTOGI, S.; SINGHAL, K.; Indian J. Chem., Sect.

Synthesis of an [(NHC)2Pd(SiMe3)2] Complex and Catalytic cis‐Bis(silyl)ations of Alkynes with Unactivated Disilanes

“…A thorough modification of the synthetic protocol, including a microwave-mediated cyclization step, allowed us to obtain 1 in 86 % overall yield even on a gram scale (Scheme 1 ). [ 15 ]…”

Synthesis of an [(NHC)2Pd(SiMe3)2] Complex and Catalytic cis‐Bis(silyl)ations of Alkynes with Unactivated Disilanes

“…It involves the formation of the corresponding thione by a ring‐forming double condensation of N , N ′‐dimethylthiourea and acetoin, and subsequent reductive desulfurization of the thione using potassium metal, with an overall yield of about 76 %. A thorough modification of the synthetic protocol, including a microwave‐mediated cyclization step, allowed us to obtain 1 in 86 % overall yield even on a gram scale (Scheme ) 15…”

Synthesis, reactions, and biological activity of 4,5-diarylimidazole-2-thiones (Review)

“…The mixture was refluxed for 48 h to give 4-(3-(4,5-diphenyl-1H-imidazol-2-ylthio)propyl)morpholine (14), which in vitro at 10 µg/ml inhibited acyl-CoA: cholesterol-O-acyltransferase (ACAT) in 91% [23]. Imidazolethione 1, potassium t-butoxide, and 2-(3-chloropropylsulfonyl)-1-methylimidazole were reacted overnight in DMF at ambient temperature to give 2-(3-(4,5-diphenyl-1H-imidazol-2-ylthio)propylsulfonyl)-1-methyl-1H-imidazole (15), which gave the maximum inhibition of increase in plasma cholesterol induced by a cholesterol-supplemented diet [24]. The asymmetric oxidation of sulfide 16 optimized using 0.5 mol equivalent of Ti(OPr-i) 4 and 1 equiv.…”

“…have been prepared similarly [10][11][12][13][14]. An eco-friendly synthesis of some 1,4,5-triarylimidazole-2-thiones 2 and 1,3,4,5-tetraarylimidazole-2-thiones involves benzoin condensation with various N-substituted thioureas and N,N'-disubstituted thioureas over recyclable inorganic solid catalyst using microwave irradiation [15]. The condensation reactions of furfural with thiourea led to 4,5-di(furan-2-yl)-1H-imidazole-2-thiol (3), which was used as an accelerator of rubber vulcanization [16,17].…”