Electron impact mass spectral studies of some 2-(2′-benzothiazoyl)- and 2-(2′-benzimidazolyl)-6-aryl-4,5-dihydro3(2H) - pyridazonines

✍ Scribed by S. N. Sawhney; Sanjay Bhutani; Dharam Vir

• Publisher: John Wiley and Sons
• Year: 1987
• Tongue: English
• Weight: 173 KB
• Volume: 22
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/oms.1210220717

✦ Synopsis

Benzothiazoly1)-and 2-(2'-Benzirnidazolyl)-6-aryl-4,5-dihydro-

3(2H)-pyridazinones

The compounds 2-(2'-benzothiazoly1)-and 2-(2'-benzimidazolyl)-6-aryl-4,5-dihydro-3(2H)-pyridazinones 1-9 have recently been synthesized as potential anti-inflammatory agents and some of them have exhibited significant activity.' In continuation of our studies on the mass spectra of heterocyclic compounds, we took the opportunity to study the electron impact mass spectral fragmentation pattern of these compounds. A survey of the literature revealed that mass spectral data of some simple pyridazines only have been published,' and no relevant study of pyridazinones has been reported.

An inspection of the mass spectra of compounds 1-9 reveals that significant fragmentation processes common to all the spectra involve (i) fission of the pyridazinone ring, (ii) fission of the C-N bond between the benzothiazole or benzimidazole and the pyridazinone ring systems and (iii) fission of the benzothiazole or benzimidazole nucleus in a characteristic m , m / z 108 0030 calc 108-0033