Synthesis of 7‐chloro‐9‐trifluoromethyl‐/7‐fluorophenothiazines

Abstract

Synthesis of 7‐chloro‐9‐trifluoromethyl‐/7‐fluorophenothiazines is reported by Smiles rearrangement of 5‐chloro‐3‐trifluoromethyl‐/5‐fluoro‐2‐formamido‐2′‐nitrodiphenyl sulfides. The later were obtained by the formylation of 2‐amino‐5‐chloro‐7‐trifluoromethyl‐/5‐fluoro‐2′‐nitrodiphenyl sulfides, which were prepared by the condensation of 2‐amino‐5‐fluoro‐/5‐chloro‐3‐trifluoromethyl benzenethiols with o‐halonitrobenzenes. 1‐Nitrophenothiazines have also been synthesized by the condensation of 2‐aminobenzenethiols with o‐halonitrobenzenes, involving Smiles rearrangement in situ. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:81–86, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20235

Synthesis and antimicrobial activity of 2H-pyrimido[2,1-b]benzothiazol-2-ones

“…2-Aminobenzothiazoles (3a-3f) required for the synthesis of 4-phenyl-2H-pyrimido[2,1-b] benzothiazol-2-ones have been synthesized from substituted anilines by thiazolylation [27,28] involving the sequence of the reactions given in (Scheme 1). Thiazolylation of thioureas has also been reported by using organic ammonium tribromide (OATB) as an alternative electrophilic bromine source in place of bromine-chloroform [29].…”

Synthesis and antimicrobial activity of structurally flexible heterocycles with the 1,4-thiazine heterosystem

“…2-Aminobenzenethiols Va-g were prepared by the heterolytic cleavage of substituted 2-aminobenzothiazoles IVa-g, which were prepared by brominative cyclization of the corresponding phenylthioureas IIa-g obtained by thiocyanogenation of substituted anilines Ia-g (Scheme 1) [30][31][32][33][34].…”

N-bridged heterocycles: regiospecific synthesis of 2-methyl-4H-pyrimido[2,1-b]benzothiazol-4-ones

“…2-aminobenzothiazoles required for the synthesis of 2-methyl-4H-pyrimido[2,1-b]benzothiazol-4-ones have been synthesized from substituted anilines by thiazolylation [11][12][13] involving the sequence of the reactions given in Scheme 3. The thiazolylation of thioureas has also been reported recently by using organic ammonium tribromide (OATB) as an alternative electrophilic bromine source in place of bromine and chloroform [17].…”

“…In view of the structural diversity and pharmacological significance of N-bridged heterocycles resulting in the fusion of two biodynamic heterosystems and our continuing efforts of synthesizing especially nitrogen-and sulfur-containing heterocycles of potential therapeutic interest [11][12][13], we have synthesized novel bioactive heterocycles, 2-methyl-4H-pyrimido [2,1-b]benzothiazol-4-ones, which involve the structural fusion of two structurally as well pharmacologically interesting heterocyclic systems [14][15][16]; benzothiazole and pyrimidine. As a result of the structural fusion of two heterocyclic systems, the pyridine type nitrogen atom in pyrimidine and in benzothiazole will be transformed into pyrrole type nitrogen and the resulting fused heterocyclic system will exhibit combinatorial characteristics of pyrrole, thiophene, and pyridine, along with other structural features.…”