Syntheses of heterocyclic fused thiazole acetic acids. 2

Abstract

A number of tricyclic and bicyclic fused thiazole-2-acetic acid derivatives were prepared and the chemistry and biological properties of these compounds are discussed. Many of the esters exhibited antitubercular activity. The bicyclic thiazole-2-acetic acids had antidepressant activity. Interesting antimetastatic activity against Lewis lung tumor in mice was found with several compounds, in particular, the thiazolo[3,2-a]benzimidazole-2-acetic acid derivative XI.

The structure of methyl 2-chloro-8-oxo-6H,8H-[1]benzopyrano[4',3':4,5]imidazo[2,1-b][1,3]thiazine-10-carboxylate

“…Levamisole (2,3,5,thiazole hydrochloride), (1), has shown powerful broad-spectrum anthelmintic properties (Thienpont, Vanparijs, Raemaekers, Vandenberk, Demoen, Allewijn, Marsboom, Niemegeers, Schellekens & Janssen, 1966;Englemann & Richardson, 1986) as well as a wide variety of other useful medicinal characteristics (Van Belle, 1972;Chan & Kellen, 1975;Chirigos, 1977Chirigos, , 1981Symoens & Rosenthal, 1977;Hara, Kayama & Fukushima, 1981). Analogs of (1) have been a subject of considerable interest in recent years (Bell & Wei, 1976;Bhargave, Lee, Huang, Cunningham & Agrawal, 1977), such as (2) (Fenichel, Gregory & Album, 1976;Tagliabue, Allesandri, Polentarutti, Montovani, Falantano, Vecehi, Garattini & Spreafico, 1978) and (3) (Hara et al, 1981), and have prompted research into newer methods to obtain highly substituted 2H-benzimidazole-2-thione systems. During the course of some work with thiazoloimidazole acetic acids (Radhakrishna & Berlin, 1978), we had the occasion to prepare 4,5-(8-ehlorochroman)-[2,3-d]imidazole-2-thio (4).…”

A Green Approach for the Synthesis of 1-Methyl-2-(alkylthio)-1H-benzimidazoles

“…Benzimidazoles are an important class of bioactive molecules in the field of drugs and pharmaceuticals 2 . 2-Mercaptobenzimidazole derivatives having substitution at either the nitrogen or sulfur are reported to exhibit a broad spectrum of biological activity [3][4][5][6][7][8] .…”

Bis(α‐bromo ketones): Versatile Precursors for Novel Bis(s‐triazolo[3,4‐b][1,3,4]thiadiazines) and Bis(as‐triazino[3,4‐b][1,3,4]thiadiazines)

“…α‐Bromo ketones are valuable compounds, which are useful in the synthesis of a variety of heterocycles as well as in other synthetic applications including cross aldol condensations , enaminoketones and Favorskii rearrangements …”