35247-31-5Relevant academic research and scientific papers
Features of reactions of quaternary salts derived from (4Z)-5-(bromomethyl) -2,2,6,6-tetra-methylhept-4-en-3-one. Synthesis of azolo[a]azepine and indolizine derivatives
Potikha,Turelik,Kovtunenko
experimental part, p. 334 - 342 (2012/09/11)
The alkylation of 1-alkyl-2-methyl-1H-imidazoles, 1,2-dimethyl-1H- benzimidazole, and 2-R-pyridines by (4Z)-5-(bromomethyl)-2,2,6,6- tetramethylhept-4-en-3-one gives 1-alkyl-3-[(2Z)-2-tert-butyl-5,5-di-methyl-4- oxohex-2-en-1-yl]-2-methyl-1H-imidazol-3-ium, -1H-benzimidazol-3-ium, and 2-R-pyridinium bromides. Heating solutions of these diazolium salts in ethanol with potassium carbonate leads to 1,5-dihydroimidazo[1,2-a]azepinium and 5,10-dihydroazepino[1,2-a]benzimidazolium derivatives, while heating the pyridinium salts with triethylamine leads to indolizine derivatives. Heating solutions of quaternary salts derived from 1,2-dimethyl-1H-imidazole and 2-methylpyridine in acetic anhydride gives allylic rearrangement products, namely, 3-[(2Z)-2-tert-butyl-5,5-dimethyl-4-oxohex-1-en-1-yl]-1,2-dimethyl-1H- imidazol-3-ium and -2-methylpyridinium bromides, which under the action of base (MeONa for the diazolium salt and Et3N for the pyridinium salt) are converted into 1,5-dihydroimidazo[1,2-a]azepinium and indolizine derivatives, respectively.
