117157-62-7

Upstream product

• 288-13-1 NH-pyrazole 
• 934-34-9 2-hydroxybenzothiazole 
• 116928-25-7 benzo[d]thiazol-2-yltriphenylphosphonium trifluoromethanesulfonate 
• 95-16-9 1,3-Benzothiazole 
• 1123-99-5 2-iodobenzothiazole 
• 615-20-3 2-chlorobenzo[d][1,3]thiazole 
• 102-52-3 malonaldehydebis(dimethylacetal) 
• 615-21-4 1,3-benzothiazol-2-ylhydrazine 

Relevant academic research and scientific papers

C-H Functionalization of Benzothiazoles via Thiazol-2-yl-phosphonium Intermediates

Benzothiazoles undergo regioselective C2-H functionalization with triphenylphosphine to form thiazol-2-yl-triphenylphosphonium salts, and these phosphonium salts react with a wide range of O- A nd N-centered nucleophiles to give the corresponding ethers, amines, and C-N biaryls. The reactions proceed under mild conditions and allow for the recovery of triphenylphosphine at the end of the sequence. In the presence of hydroxide, phosphonium salts undergo disproportionation, resulting in the reduction of the benzothiazole, which is useful for specific C2 deuteration of benzothiazoles.

Synthesis of C,N′-linked bis-heterocycles using a deprotometalation-iodination-N-arylation sequence and evaluation of their antiproliferative activity in melanoma cells

Benzothiophene, benzofuran, benzothiazole and benzoxazole were deprotometalated using the lithium-zinc combination prepared from ZnCl 2·TMEDA (TMEDA = N,N,N′,N′- tetramethylethylenediamine, 1 equiv) and lithium 2,2,6,6-tetramethylpiperidide (LiTMP, 3 equiv). Subsequent interception of the 2-metalated derivatives using iodine as electrophile led to the iodides in 81%, 82%, 67% and 42% yields, respectively. These yields are higher (10% more) than those obtained using ZnCl2·TMEDA (0.5 equiv) and LiTMP (1.5 equiv), except in the case of benzoxazole (10% less). The crude iodides were involved in the N-arylation of pyrrole, indole, carbazole, pyrazole, indazole, imidazole and benzimidazole in the presence of Cu (0.2 equiv) and Cs2CO3 (2 equiv), and using acetonitrile as solvent (no other ligand) to provide after 24 h reflux the expected N-arylated azoles in yields ranging from 33% to 81%. Using benzotriazole also led to N-arylation products, but in lower 34%, 39%, 36% and 6% yields, respectively. A further study with this azole evidenced the impact of 2,2,6,6-tetramethylpiperidine on the N-arylation yields. Most of the C,N′-linked bis-heterocycles thus synthesized (in particular those containing benzimidazole) induced a high growth inhibition of A2058 melanoma cells after a 72 h treatment at 10-5 M.

Convenient and reliable routes towards 2-aminothiazoles: Palladium-catalyzed versus copper-catalyzed aminations of halothiazoles

Two efficient methods for the amination of 2-halothiazoles are presented here. A first protocol requires a Pd/L system. Several 2-aminothiazoles were synthesized under optimized conditions and isolated in good yields. The first palladium-catalyzed C-N coupling reactions between 2-halothiazoles and primary alkylamines are presented. In a second part, ligand-free copper-catalyzed aminations of 2-halothiazoles by alkylamines and aniline in a green solvent have been developed. The protocol is very effective for primary and secondary amines and perfectly tolerates the presence of another halide moiety on the 2-halothiazole. The reaction occurs under the assistance of microwave irradiation, which drastically decreases the reaction time. The reaction leads to the formation of 2-aminothiazoles, key molecules in pharmaceutical research. Copyright

Laccase-catalysed homocoupling of primary aromatic amines towards the biosynthesis of dyes

Coloured disubstituted benzoquinonimine trimeric structures are obtained as main reaction products of the oxidation of p-electron donor pri-mary aromatic amines using two different laccases, CotA-laccase from Baccilus subtilus and TvL from Trametes versicolor. These orange-red to purple products, presenting high molar extinction coeffi-cients, presumably result from oxidative homocou-pling reactions, through the formation of N-C bonds at positions 2 and 5, of the laccase oxidised inter-mediate as showed in the proposed oxidative path-way. The product of 1,4-phenylenediamine is shown to be the trimer known as Bandrowski's base which has an established role in hair and fur dyeing. Our results also show that the occurrence and/or rates of oxidation of aromatic amines are strongly dependent on the presence of p-electron releasing substituents in the aromatic ring and are independent on the properties of the enzyme used. Overall our data con-tribute for (i) understanding key features of laccase reactivity with p-substituted aromatic amines and (ii) establishing enzymatic processes that lead to the syn-thesis of coloured bio-products under mild condi-tions with potential impact in the cosmetic and dye industries.

Direct, metal-free amination of heterocyclic amides/ureas with NH-heterocycles and N-substituted anilines in POCl3

A POCl3-mediated, direct amination reaction of heterocyclic amides/ureas with NH-heterocycles or N-substituted anilines is described. Compared to the existing methods, this operationally simple protocol provides unique reactivity and functional

SYNTHESES OF NEW PYRAZOLE-DERIVED CHELATING LIGANDS

The preparations and spectral data for nine new N,N'-chelating ligands (5)-(13), each consisting of a pyrazole group N-linked to an azine or azole, are described.

Synthesis and NMR Spectra of 2-(Pyrazol-1-yl)benzothiazoles: Unambiguous Assignment of 3- and 5-Substituents of Pyrazole Moiety

Condensation of 2-hydrazinobenzothiazoles (1) with acetaldhyde dimethyl acetal (2) yields, depending upon the reaction conditions, either exclusively 2-(3-methylpyrazol-1-yl)benzothiazoles (4) through the intermediacy of the corresponding hydrazones (3), or a mixture of 4 and 2-(5-methylpyrazol-1-yl)benzothiazoles (5).The isomers (4 and 5) are readily distinguishable by their PMR and 13C NMR data. 2-(Pyrazol-1-yl)benzothiazoles (7) are similarly synthesized by condensation of 1 with malonaldehyde bis(dimethylacetal) (6).The methyl(or hydrogen) located at position-5 of the pyrazole moiety gets deshielded because of the lone pair effect of the nitrogen of the benzothiazole ring or due to the ring current.