Microwave‐Assisted Three‐Component Synthesis of 7‐Aryl‐2‐alkylthio‐4,7‐dihydro‐1,2,4‐triazolo [1,5‐a]pyrimidine‐6‐carboxamides and Their Selective Reduction.

Abstract

Fused pyrimidine derivatives R 0515Microwave-Assisted Three-Component Synthesis of 7-Aryl-2-alkylthio-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidine-6-carboxamides and Their Selective Reduction. -A rapid access to the title compounds (15 examples) is accomplished in high yields and excellent purities by the condensation of triazoles with aromatic aldehydes and acetoamides under microwave irradiation in 5 minutes. Selective reduction of the C=C double bond in the pyrimidine ring of products (IV) affords structurally modified tetrahydropyrimidines (V) as single trans-trans isomers. -(CHEBANOV*, V. A.; MURAVYOVA, E. A.; DESENKO, S. M.; MUSATOV, V. I.; KNYAZEVA, I. V.; SHISHKINA, S. V.; SHISHKIN, O. V.; KAPPE, C. O.; J.

Synthesis and Evaluation of 1,2,4-Triazolo[1,5-a]pyrimidines as Antibacterial Agents Against Enterococcus faecium

“…Subsequently, equal amounts of derivatives I , II , and III were heated in DMF for roughly 15–20 min (with a temperature of 130–160 °C), which yielded the desired compounds after the work up. This three-component Biginelli-like heterocyclization method , afforded the rapid and efficient synthesis of a focused library of these compounds, using commercially available reagents. In light of the essentially single-pot reactions that led to these molecules, only the final compounds have been characterized in this report.…”

“…The 1,2,4-triazolo­[1,5- a ]­pyrimidine analogues were synthesized by using a modification of a known method . Equimolar mixtures of compounds I , II , and III (0.80–2.0 mmol) were heated in 0.30–0.50 mL of DMF within the temperature range of 130–160 °C for 15–20 min.…”

Synthesis of pyrimidine-6-carbonitriles, pyrimidin-5-ones, and tetrahydroquinoline-3-carbonitriles by new superb oxovanadium(V)-[5,10,15,20-tetrakis(pyridinium)-porphyrinato]-tetra(tricyanomethanide) catalyst via anomeric based oxidation

“…Triazolopyrimidines and tetrahydroquinolines were synthesized by using numerous approaches and catalysts such as thiamine hydrochloride (VB 1 ) 23 , Nafion-H 24 , phthalhydrazide-MCM-41 (P-MCM-41) 25 , boric acid under aqueous micellar medium 26 , [DABCO](SO 3 H) 2 Cl 2 and [DABCO](HSO 3 ) 2 (HSO 4 ) 2 27 , DBU 28 , microwave irradiation 29 , etc. [30][31][32][33][34][35][36][37][38][39] .…”

A Novel Mechanistic Study on Ultrasound-Assisted, One-Pot Synthesis of Functionalized Benzimidazo[2,1-b]quinazolin-1(1H)-ones

“…A three-component MCR involving 3-aminotriazole, an aldehyde and 1,3-dicarbonyl compounds was first reported by Kappe et al for microwave assisted synthesis of triazole fused pyrimidine-6-carboxamides. 14 Similar multicomponent reactions using benzimidazole was adapted for the synthesis of pyrimidobenzimidazoles and benzimidazo-quinazoline derivatives. 14 Earlier we reported a rapid reaction of polymer-bound N-alkylated 2-amino benzimidazoles, aldehydes, and 1,3-diones under microwave irradiation generated triazafluor-enes.…”

“…14 Similar multicomponent reactions using benzimidazole was adapted for the synthesis of pyrimidobenzimidazoles and benzimidazo-quinazoline derivatives. 14 Earlier we reported a rapid reaction of polymer-bound N-alkylated 2-amino benzimidazoles, aldehydes, and 1,3-diones under microwave irradiation generated triazafluor-enes. 16 This transformation still remains an attraction in synthesis and in medicinal chemistry as it produces biologically interesting benzimidazodihydropyrimidine skeleton.…”