85433-21-2

Upstream product

• 70787-27-8 N-(2-bromophenyl)benzamide 
• 615-36-1 2-bromoaniline 
• 98-88-4 benzoyl chloride 

Downstream Products

• 883-93-2 2-Phenylbenzothiazole 
• 70787-27-8 N-(2-bromophenyl)benzamide 
• 1044146-16-8 4-bromo-2-phenylbenzo[d]thiazole 

Relevant academic research and scientific papers

Photocatalyst- And Transition-Metal-Free Visible-Light-Promoted Intramolecular C(sp2)-S Formation

A photocatalyst- and transition-metal-free visible-light-induced cyclization of ortho-halothiobenzanilides has been developed. Upon irradiation with visible light, substrates undergo dehalogenative cyclization to 2-aryl benzothiazoles with high efficiency and selectivity. This photocyclization exhibits a high tolerance to various functional groups, is applicable for the synthesis of 2-alkyl benzothiazoles, and is easy to set up for gram-scale reaction.

Exogenous Photosensitizer-, Metal-, and Base-Free Visible-Light-Promoted C-H Thiolation via Reverse Hydrogen Atom Transfer

Visible-light-driven, intramolecular C(sp2)-H thiolation has been achieved without addition of a photosensitizer, metal catalyst, or base. This reaction induces the cyclization of thiobenzanilides to benzothiazoles. The substrate absorbs visible light, and its excited state undergoes a reverse hydrogen-atom transfer (RHAT) with 2,2,6,6-tetramethylpiperidine N-oxyl to form a sulfur radical. The addition of the sulfur radical to the benzene ring gives an aryl radical, which then rearomatizes to benzothiazole via RHAT.

Synthesis of Benz-Fused Azoles via C-Heteroatom Coupling Reactions Catalyzed by Cu(I) in the Presence of Glycosyltriazole Ligands

Glycosyl triazoles are conveniently accessible and contain multiple metal-binding units that may assist in metal-mediated catalysis. Azide derivatives of d-glucose have been converted to their respective aryltriazoles and screened as ligands for the synthesis of 2-substituted benz-fused azoles and benzimidazoquinazolinones by Cu-catalyzed intramolecular Ullmann type C-heteroatom coupling. Good to excellent yields for a variety of benz-fused heterocyles were obtained for this readily accessible catalytic system.

Iridium-catalyzed intramolecular C–N and C–O/S cross-coupling reactions: Preparation of benzoazole derivatives

The irdium-catalyzed intramolecular arylcarbon-hetero cross-coupling reactions with o-haloarylamides or o-haloarylamidine have been effectively achieved using KOAc and just 1 mol% catalyst. The [Ir(cod)Cl]2 was proved to be more potential for smoothly assembling functional structures benzimidazoles, benzoxazoles and benzothiazoles, which was superior to Cu- and Pd-catalyzed systems. Simultaneously, a concise and efficient synthesis of tafamidis was developed in 5-g scale.

N-Heterocyclic carbene copper(i) complex-catalyzed synthesis of 2-aryl benzoxazoles and benzothiazoles

A new and efficient synthesis of 2-arylbenzoxazoles and benzothiazoles using a copper N-heterocyclic carbene complex is described. In a simple protocol a variety of 2-substituted benzoxazoles and benzothiazoles were obtained via intramolecular coupling cyclization of 2-haloanilides/2-halothioanilides in good to excellent yields.

Conversion of thiobenzamides to benzothiazoles via intramolecular cyclization of the aryl radical cation

A new and general method has been developed for the intramolecular cyclization of thiobenzamides to benzothiazoles via aryl radical cations as reactive intermediates. The method utilizes phenyliodine(III) bis(trifluoroacetate) (PIFA) in trifluoroethanol or cerium ammonium nitrate (CAN) in aqueous acetonitrile at room temperature to effect cyclization within 30 min in moderate yields.

One-pot preparation of 2 (alkly)arylbenzothiazoles from the corresponding o-halobenzanilides

Thionation of o-halobenzanilides was carried out in the presence of Lawesson's reagent. Subsequently, the formed thioamides reacted with cesium carbonate to give the corresponding benzothiazole derivatives in the same pot. Georg Thieme Verlag Stuttgart.

Parallel synthesis of a library of benzoxazoles and benzothiazoles using ligand-accelerated copper-catalyzed cyclizations of ortho-halobenzanilides

A general method for the formation of benzoxazoles via a copper-catalyzed cyclization of ortho-haloanilides is reported. This approach complements the more commonly used strategies for benzoxazole formation which require 2-aminophenols as substrates. The reaction involves an intramolecular C-O cross-coupling of the ortho-haloanilides and is believed to proceed via an oxidative insertion/reductive elimination pathway through a Cu(I)/Cu(III) manifold. The reaction is also applicable to the formation of benzothiazoles. A variety of ligands including 1,10-phenanthroline and N,N′- dimethylethylenediamine were shown to provide ligand acceleration/stabilization in the reaction. Optimal conditions for cyclization used a catalyst combination of CuI and 1,10-phenanthroline (10 mol %). The method was amenable to a parallel-synthesis approach, as demonstrated by the synthesis of a library of benzoxazoles and benzothiazoles substituted at various positions in the ring. Most examples utilized the cyclization of ortho-bromoanilides, but orthoiodoanilides and ortho-chloroanilides also undergo a reaction under these conditions. The rate of reaction of the ortho-haloanilides follows the order I > Br > Cl, consistent with oxidative addition being the rate-determining step.

Synthesis of 2-substituted-benzothiazoles by palladium-catalyzed intramolecular cyclization of o-bromophenylthioureas and o-bromophenylthioamides

2-Amino-, and 2-alkyl-benzothiazoles have been efficiently prepared by palladium catalyzed cyclization of o-bromophenylthioureas and o-bromophenylthiamides. Results were best with the Pd2(dba)3/monophosphine catalytic system.