Synthesis, Characterization and Antimicrobial activity of 2- Amino-1,3-benzothiazole, Schiff bases and Azo dyes of 2-Amino- 1,3-benzothiazole.

Abstract

Amino-1,3-benzothiazole was synthesized and schiff bases were prepared by reacting a series of aromatic aldehydes with 2-amino-1,3-benzothiazole to form a number of potentially biologically active compounds. Azo dyes of 2-amino-1,3-benzothiazole were synthesized by reacting various aromatic amines , substituted amines and phenols. The structures of 2-amino-1,3-benzothiazole, Schiff bases and azo dyes were confirmed by using FT-IR, 1 H- NMR, Mass, UV, spectroscopic technique. The dyeing ability of azo dyes was checked by applying azo dyes on various fabrics. The tiltle compounds were also tested against representatives of gram-positive and gram - negative bacteria by agar diffusion method. Ampicillin was used as positive control. Key-words : Benzothiazole , aldehydes, schiffs bases, azo dyes, antimicrobial I. Introduction : The twentieth century has been characterized both by a drastic reduction in the mortality caused by infection diseases and by a rise in the control of neoplastic pathologies. Nevertheless, micro-organisms and viruses, on the other hand and tumours on the other still represent a dreadful menace to men's health and therefore, for a more efficient control, require the steady development of novel and more powerful drugs. It is known that schiff bases possesses biological activity such as antimicrobial, antifungal, antitumor, anti-HIV and herbicides. So we thought to prepare schiffs bases of 2-amino-1,3-benzothiazole and test their biological activity. The present world is very much fascinated by the different and brilliant colors in every-day life. The colors find a great importance in men's life in various fields such as cloths, food colors , attractive furniture,etc. In biology for staining purpose and in analytical chemistry as an indicators for various titrations. So, we tried to synthesise azo dyes of 2-amino-1,3-benzothiazole. i. Schiffs bases were prepared by condensing 2-aminobenzothiazole with series of aromatic aldehydes in ethanol. The products obtained were recrystallized from ethanol. The purity and structure of compounds prepared were confirmed by TLC, M.P. and spectral studies. ii. Azo dyes were prepared by diazotization of 2-amino-1,3-benzothiazole with NaNO2 and H2SO4 followed by coupling with series of aromatic amines and phenols. Dyes obtained were recrystallized from acetone- ethanol mixture. The purity and structures were confirmed by TLC, M.P. and spectral analysis. Dyeing ability of the said compounds was tested by dyeing on various fabrics using standard dyeing method. Dyes synthesised tested as an indicator for acid-base titrations and complexometric titrations. iii. All these compounds prepared were screened against human pathogenic bacteria.