Synthesis of some 4H-pyrimido[2,1-b]benzothiazol-4-ones was written by Alaimo, Robert J.. And the article was included in Journal of Heterocyclic Chemistry in 1973.Product Details of 6294-52-6 This article mentions the following:
A series of 8-substituted and 7,8-disubstituted-4-oxo-3-(4H-pyrimido[2,1-b]benzothiazole)carboxylic acids (I) and esters including a 9-aza analog were synthesized from substituted 2-aminobenzothiazoles and di-Et ethoxymethylenemalonate. No significant antiparasitic activity was detected. In the experiment, the researchers used many compounds, for example, 5,6-Dimethoxybenzo[d]thiazol-2-amine (cas: 6294-52-6Product Details of 6294-52-6).
5,6-Dimethoxybenzo[d]thiazol-2-amine (cas: 6294-52-6) belongs to thiazole derivatives. The higher aromaticity of thiazole is due to delocalization of a lone pair of sulfur electrons across the ring, which is evidenced by chemical shifts of ring hydrogen at δ 7.27 and 8.77 ppm (C2 and C4), indicating diamagnetic ring current.Various laboratory methods exist for the organic synthesis of thiazoles. For example, 2,4-dimethylthiazole is synthesized from thioacetamide and chloroacetone.Product Details of 6294-52-6
Referemce:
Thiazole | C3H3NS – PubChem,
Thiazole | chemical compound | Britannica