Green synthesis and characterisation of novel [1,3,4]thiadiazolo/benzo[4,5]thiazolo[3,2- a]pyrimidines via multicomponent reaction using vanadium oxide loaded on fluorapatite as a robust and sustainable catalyst

Nagaraju Kerru; Lalitha Gummidi; Surya Narayana Maddila; Sandeep V H S Bhaskaruni; Suresh Maddila; Sreekantha B Jonnalagadda

doi:10.1039/d0ra02298e

Green synthesis and characterisation of novel [1,3,4]thiadiazolo/benzo[4,5]thiazolo[3,2- a]pyrimidines via multicomponent reaction using vanadium oxide loaded on fluorapatite as a robust and sustainable catalyst

RSC Adv. 2020 May 27;10(34):19803-19810. doi: 10.1039/d0ra02298e. eCollection 2020 May 26.

Authors

Nagaraju Kerru¹, Lalitha Gummidi¹, Surya Narayana Maddila¹, Sandeep V H S Bhaskaruni¹, Suresh Maddila¹, Sreekantha B Jonnalagadda¹

Affiliation

¹ School of Chemistry & Physics, University of KwaZulu-Natal, Westville Campus Chiltern Hills Durban-4000 South Africa jonnalagaddas@ukzn.ac.za +27 31 2603091 +27 31 2607325.

Abstract

We synthesised materials with different loadings of vanadia on fluorapatite (V₂O₅/FAp), fully characterised their structural properties using various spectral techniques including TEM, BET, XRD, FT-IR, SEM and EDX and assessed their prowess as catalysts. The 2.5% V₂O₅/FAp exhibited excellent activity for the synthesis of novel [1,3,4]thiadiazolo[3,2-a]pyrimidines and benzo[4,5]thiazolo[3,2-a]pyrimidines. The one-pot three-component fusion reaction between chosen substrates of 1,3,4-thiadiazole-amines or 2-amino-benzothiazole, aldehydes and active methylene compounds in ethanol solvent at room temperature gave an excellent yield of products (90-97%) in a swift reaction (25-30 min). The advantages of this protocol are rapid synthesis, mild reaction conditions, green solvent, easy work-up, eco-friendliness, reusability of catalyst and no need for column chromatography.