A fascinating click strategy to novel 1,2,3-triazolium based organic-inorganic hybrids for highly accelerated preparation of tetrazolopyrimidines

Herein, click reaction is used for the preparation of novel organic-inorganic Bronsted acidic ionic solids (BAISs) as new catalysts for the efficient synthesis of tetrazolopyrimidines. A series of mono and disubstituted-1,2,3-triazoles were synthesized under click reaction condition. The prepared 1,2,3-triazoles underwent reaction with 1,4-butanesultone to provide novel solid 1,2,3-triazolium N- butyl sulfonate zwitterions. Then, the reaction of phosphotungstic acid with the obtained zwitterions led to the novel 1,2,3-triazolium-N-butyl sulfonic acid phosphotungstate as acidic ionic solids. The synthesized BAIS catalysts were fully characterized using FTIR, H-1 and C-13 NMR, XRD, elemental analysis (CHNS), TG and DSC techniques. The introduced novel hybrids were used as efficient catalysts for the synthesis of targeted methyl-7-aryl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate and 6,6-dimethyl-9-aryl-5,6,7,9-tetrahydrotetrazolo[5,1-b]quinazolin-8(4H)-one derivatives via multicomponent reaction of aromatic aldehydes, active methylene compounds and 5-aminotetrazole. Low amount of the prepared 1,2,3-triazolium-N-butyl sulfonic acids phosphotungstate catalysts (5-10 mmol%) gave desired products in short times (20-45 min) with excellent yields (87-93%). Novelty of the introduced catalysts, ease of recovery and reusability up to four repeated runs with no significant decrease in the yields are highlighted superiorities of the introduced organic-inorganic hybrid catalysts.

Automated summary

In this study, novel organic-inorganic Bronsted acidic ionic solids (BAISs) were prepared using click reaction and used as efficient catalysts for the synthesis of tetrazolopyrimidines. The introduced catalysts have the advantages of ease of recovery, reusability, and high yields of the desired products in a short time.