Electronic spectra of benzothiazolone and its derivatives was written by Simov, D.;Antonova, A.. And the article was included in Godishnik na Sofiiskiya Universitet Sv. Kliment Okhridski, Khimicheski Fakultet in 1976.HPLC of Formula: 62266-81-3 This article mentions the following:
UV spectra are tabulated for benzothiazolones I (R = H, 3-Me, 6-Me, 5-MeO, 6-MeO, 5-Cl, 6-Cl, 6-Br, 5-Me2NSO2, 6-Me2NSO2, 5-NO2, 6-NO2) in 20% solution in EtOH and in H2O at pH 0.5, 7 and 11.5. The peaks for I (R = H, Me) came at lower wavelengths than those for the other I. In the experiment, the researchers used many compounds, for example, 6-Chlorobenzo[d]thiazol-2(3H)-one (cas: 62266-81-3HPLC of Formula: 62266-81-3).
6-Chlorobenzo[d]thiazol-2(3H)-one (cas: 62266-81-3) 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. The nitrogen in thiazole is sp2 hybridized and the lone pair of electrons localized on the nitrogen is less reactive due to increased aromatic character and decreased basicity. It is protonated and alkylated/acylated at nitrogen forming hydrochloride and quaternary thiazolium salt.HPLC of Formula: 62266-81-3
Referemce:
Thiazole | C3H3NS – PubChem,
Thiazole | chemical compound | Britannica