Yield:-

Reaction Conditions:

with bromine in chloroform at 5; for 6 h;

Steps:

Synthesis of 2-Amino-5,7-dimethylbenzothiazole 3

In a round-bottomed flask equipped with a mechanical stirrer and a dropping funnel, 5,7-dimethyl phenylthiourea 2 (0.1 mol) and chloroform (100 ml) were taken. A solution of bromine (0.1 mol) in chloroform (100 ml) was added dropwise with stirring for a period of two hours. Temperature of reaction mixture remains below 5 C during the reaction. Stirring was continued for a period of 4 h. After the addition of bromine solution, the contents of round-bottomed flask were refluxed for about 4 h till the evolution of HBr ceased. The solid obtained was treated with SO₂ water and filtered. The filtrate was neutralized with aqueous ammonia solution. The precipitate was filtered, washed well with water, and crystallized from ethanol.

References:

Agarwal, Shikha;Agarwal, Dinesh Kumar;Gautam, Naveen;Agarwal, Kshamta;Gautam, Dinesh Chandra [Journal of the Korean Chemical Society,2014,vol. 58,# 1,p. 33 - 38]