José Camacho

Synthesis, antimalarial activity, structure–activity relationship analysis of thieno-[3,2-b]benzothiazine S,S-dioxide analogs

An improved procedure for the synthesis of 3-amino-9-arylsubstituted-thieno[3,2-b]benzothiazine S,S-dioxide 2-decarboxylated is reported. Thieno-[3,2-b]benzothiazine S,S-dioxide derivatives were investigated for their abilities to inhibit beta-hematin formation, hemoglobin hydrolysis and in vivo for their efficacy in rodent Plasmodium berghei. Compounds 5j-o were the most promising as inhibitors of hemoglobin hydrolysis, however, the compounds are not as efficient as chloroquine. A structure-activity relationship (SAR) study was carried out in this series. Our results allow us to determine the minimal structural requirements to produce the biological response.

A convenient route to 2-substituted benzothiazole-6-carboxylic acids using nitrobenzene as oxidant

Various substituted benzothiazole-6-carboxylic acids (4a–i) have been prepared by the condensation of 4-amino-3-mercaptobenzoic acid and aldehydes in nitrobenzene as oxidant. Compound 4i was found to be a good candidate as an inhibitor of β-hematin formation in vitro.

N'-Formyl-2-(5-nitrothiophen-2-yl)benzothiazole-6-carbohydrazide as a potential anti-tumour agent for prostate cancer in experimental studies.

Benzothiazoles (BZTs) represent organic compounds with different biological actions. In this study we aimed to investigate ten newly synthesized BZT derivatives as potential anti‐tumour agents against prostate cancer in vitro and in vivo.

Synthesis and crystal structure of ethyl 7-chloro-3-amino-9-(4-bromophenyl)thieno-[3,2-b]benzothiazine 4,4-dioxide 2-carboxylate

The X-ray crystal structure of 7-chloro-3-amino-9-(4-bromophenyl)thieno-[3,2-b]benzothiazine 4,4-dioxide 2-carboxylate 1 is determined. The thiophene ring and the exocyclic ester group adopt a co-planar conformation, which is stabilised by an intramolecular hydrogen bond. The moderate antimalarial activity shown by this compound appears to be related to the formation of such an intramolecular N–H···O =C hydrogen bond.