Indolo benzothiazepine

Oxidation on the sulfur atom of pyrrolo-benzothiazepine 175 (Scheme 34, Section 2.3.1 (1994MI283)), indolo benzothiazepine (Scheme 65, Section 3.3.1.2 (1998MI139)) and pyrrolo-benzothiadiazepine (Scheme 74, Section 4.2 (1994SC2685)) proceeds smoothly with hydrogen peroxide in acetic acid or with MCPBA to afford cyclic sulfones in good yields. 

Arylthioindole-2-carboxylic acids 303, obtained from aryl disulfides and indole-2-carboxylic acids, afford tetracyclic 5H-indolo-[3,2-fc][l,5]benzothiazepin-6(7H)-ones 304 on treatment with EDC-DMAP (Scheme 65 (1998MI139)). 

A number of papers have been published on the chemistry and biological activity of 1,5-benzothiazepines containing an additional bicyclic system fused to different positions of the seven-membered ring. Tetracyclic indolo-, benzofuro-, pyrazolopyrido-, quino-, benzopyrano-, benzothio-pyrano-, quinazolino-, and quinoxalino-l,5-benzothiazepines are known. 

Two examples of synthetic approaches to indolo-1,5-benzothiazepines have been reported along with investigations of their biological activity. 

Indolo[2,3-6][ 1,5]benzothiazepines (130 and 132) were prepared by Fisher indolization of phenylhydrazone derivatives 129 and 131, respec-... 

Deoxygenation of l,2-dimethyl-3-(o-nitrophenylthio)indole (133) with an excess of triethyl phosphite, either neat or with cumene as solvent, at 160°C afforded indolo[2,3-c][l,5]benzothiazepine (134) in 34% yield. This product may arise via //wo-substitution by the initially formed nitrene to the 3-position of the indole nucleus to give the intermediate 135 (Scheme 41) [88JCR(S)272]. 

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