Montmorillonite K10-catalyzed synthesis of N-fused imino-1,2,4-thiadiazolo isoquinoline derivatives

Abstract

A novel synthesis of N-fused imino-1,2,4-thiadiazolo derivatives is described. This approach involves the inexpensive, nontoxic, recoverable, and easy to handle montmorillonite K10 that catalyzes the coupling of 3-aminoisoquinolines and phenylisothiocyanates to afford the N-fused imino-1,2,4-thiadiazolo isoquinoline motifs in exemplary yields. The main attractions of this synthetic strategy were simple procedure and excellent yields.

Montmorillonite-catalysed coupling reactions: a green overview

“…A novel strategy for the synthesis of N -fused imino-1,2,4-thiadiazolo derivatives was developed using montmorillonite K10 as an effective catalyst. 81 The reaction between phenylisothiocyanates and 3-aminoisoquinolines (1 : 1 molar ratio) gave maximum yield at room temperature in acetonitrile with 10 mol% of montmorillonite K10 (Scheme 54). The substrate scope was explored under this optimum condition where the arylisothiocyanates with electron-withdrawing groups gave a slightly smaller yield compared with that with an electron-donating group.…”

Green Chemistry in Organic Synthesis: Recent Update on Green Catalytic Approaches in Synthesis of 1,2,4-Thiadiazoles

“…Synthesis of N-Fused Imino-1,2,4-Thiadiazolo Isoquinoline via Montmorillonite K10-Catalyst Chacko and Shivashankar for the first time reported the green, recoverable, inexpensive, nontoxic and efficient oxidizing montmorillonite K10-catalyst for the rapid construction of N-S Bond formation to afford 1,2,4-thiadiazolo isoquinoline structural hybrids in good yields. In this simple synthetic protocol, 3-aminoisoquinolines 40 were coupled with substituted isothiocyanates 35 to construct the N-S Bond of 1,2,4-thiadiazole core to achieve N-fused imino-1,2,4-thiadiazolo isoquinoline scaffolds in excellent yields as displayed in Scheme 17 [269].…”

Zinc chloride catalyzed multicomponent synthesis of pyrazolopyridocoumarin scaffolds

“…Based on the literature survey and in continuation with our ongoing research work on the preparation of biologically active heterocycles, [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52] we desire to report a novel method for synthesis of pyrazolopyridocoumarins from simple and readily available starting materials, which went through the simultaneous construction of pyrazole and pyridine rings.…”