92537-77-4Relevant academic research and scientific papers
Synthesis and Mass Spectral Studies of 6-Fluoro-2-(3'-methyl-5'-oxo-2'-pyrazolin-1'-yl)benzothiazole and Its 4'-Substituted Analogues
Singh, S. P.,Kodali, Dharma R.,Prakash, Indra,Prakash, Om,Sawhney, S. N.
, p. 125 - 128 (2007/10/02)
Condensation of 6-fluoro-2-hydrazinobenzothiazole with ethyl acetoacetate, substituted ethyl acetoacetates and diethyl acetylsuccinate affords the title compound (IIa), its 4'-substituted-alkyl/chloro analogues (IIb-d) and 2-(4'-carbethoxymethyl-3'-methyl-5'-oxo-2'-pyrazolin-1'-yl)-6-fluorobenzothiazole (IIe) respectively.Alkaline hydrolysis of IIe furnishes the corresponding acid (IIf).The mass spectral studies of II reveal that in addition to the fragmentation associated with benzothiazole moiety, pyrazolone ring undergoes fission generating ions which can be formulated as ionized benzothiazolyl isocyanate and protonated benzothiazolyl isocyanate.This mode of fragmentation indicates the existence of II in keto as well as enol forms under the mass spectral conditions.The elemental composition of all these ions have been confirmed by accurate mass measurements.It has been shown that substitution of fluorine in IIe by hydrogen (IIIa), chlorine (IIIb) and methoxyl group (IIIc) does not alter the fragmentation pattern.Compound IIf exhibits significant antiinflammatory activity.
