Synthesis of 2-substituted-6-hydroxy and 6-methoxy benzothiazoles from 1,4-benzoquinone

Abstract

A few 2-substituted-6-hydroxy and 6-methoxybenzothiazoles have been prepared from ethyl 6-hydroxybenzothiazole-2-carboxylate, obtained by oxidation of ethyl (R)-2-amino-3-(2,5-dihydroxyphenylsulfanyl)propanoate hydrochloride, in turn prepared from 1,4-benzoquinone.

Quaternary Ammonium Promoted Ultra Selective and Sensitive Fluorescence Detection of Fluoride Ion in Water and Living Cells

“…11 Ethyl 6-hydroxybenzothiazole-2-carboxylate was synthesized in two steps according to the previous literature. 15 After ester hydrolysis, further coupling between the 6-hydroxybenzothiazole-2-carboxylic acid and corresponding ethanol amine, N,N-dimethylamino ethyl amine and trimethylammonium ethyl amine chloride afforded the intermediates 3, 4, and 5. Probes L1, L2, and L3 were then synthesized through selective silylation of phenol moiety of intermediates 3, 4, and 5 with tert-butyldiphenylsilyl chloride (TBDPS-Cl).…”

“…6-Hydroxybenzothiazole was first chosen as the fluorophore for rational design of quaternary ammonium promoted fluoride probes due to its small size and relative biological compatibility (Scheme ) . Ethyl 6-hydroxybenzothiazole-2-carboxylate was synthesized in two steps according to the previous literature . After ester hydrolysis, further coupling between the 6-hydroxybenzothiazole-2-carboxylic acid and corresponding ethanol amine, N , N -dimethylamino ethyl amine and trimethylammonium ethyl amine chloride afforded the intermediates 3 , 4 , and 5 .…”

A Low-Cost, Sensitive Reporter System Using Membrane-Tethered Horseradish Peroxidase for Efficient Gene Expression Analysis

“…This procedure had increased reliability, but also it increased the duration of the process and the steps required. However, most importantly, the yield of cyanobenzothiazole was 42% with a three step synthesis using anilines and Appel’s salt to give an overall yield of 54% without the palladium metal, to provide better accessibility with a much lower price for luciferin through generating derivatives with different functional groups. − Siebring-van Olst et al also sought to generate a more affordable luciferase reporter assay by manipulating and optimizing the composition of the substrate buffer to decrease the reagent cost in a single screening by 45-fold . Nevertheless, the need for detergent or an enzyme-based cell membrane disruption method, to decrease the time spent before luminescence analysis and to generate a more homogeneous environment for an enzyme–substrate catalytic reaction, resulted in an increase of variation in drug selection or protein interaction and also an increase in the time taken for the experimental procedure.…”