Hexachlorocyclotriphosphazene (HCCP)-Mediated Direct Formation of Thioethers and Ethers from Quinazolin-4(3H)-ones

Abstract

A hexachlorocyclotriphosphazene (HCCP)-mediated direct formation of quinazoline (thio)ethers from quinazolin-4(3H)-ones has been developed. Treatment of quinazolin-4(3H)-ones with HCCP, diisopropylethylamine (DIPEA), and thiophenols resulted in formation of the corresponding 4-arylthioquinazoline derivatives in moderate to excellent yields. This method has also been utilized to prepare 4-aryloxyquinazoline and 4-alkoxyquinazoline derivatives using phenols and sodium alkoxides as the nucleophiles.

Cu–benzotriazole-catalyzed electrophilic cyclization of N-arylimines: a methodical tandem approach to O-protected-4hydroxyquinazolines-

“…5,6 In the past, synthesis of Oprotected-4-hydroxyquinazoline (PHQ) was achieved through chemical transformation of various starting materials as described in Scheme 1. [5][6][7][8][9][10] All these reported methods (1a-1d) involve synthesis from bicyclic-N-heterocycles, with limitations including expensive catalysts such as BOP 7 /HCCP, 8 or harsh conditions. In this context, we developed an efficient copperbenzotriazole (Cu-BtH)-catalyzed tandem method (1e) for synthesis of PHQ through intramolecular electrophilic cyclization of N-arylimines obtained during the reaction of 2-aminobenzonitriles (2-AN) with aldehydes.…”

One-Step Synthesis of Thieno[2,3-d]pyrimidin-4(3H)-ones via a Catalytic Four-Component Reaction of Ketones, Ethyl Cyanoacetate, S8, and Formamide

“…We could readily transform product 5a into cyclic amidine 6 in 71% yield using the reported DIPEA-promoted direct amination of a cyclic amide (Scheme 3). 19 Compared to traditional two-step amination of 5a (chlorination and S N Ar substitution), this method is more straightforward. This also illustrates the versatile, rapid synthesis of high value products starting with our procedure.…”

Synthesis, Antiviral Bioactivity of Novel 4-Thioquinazoline Derivatives Containing Chalcone Moiety

“…4-Thioquinazoline and their derivatives, an important class of heterocyclic compounds, have a wide range of biological properties [2], including antibacterial [3,4], antifungal [5][6][7], and anticancer [8] activities. Over the past few years, the synthesis and study of bioactivity of 4-thioquinazoline derivatives have attracted considerable attention.…”