87926-08-7Relevant articles and documents
Enamine Rearrangement of 2-Benzylpyridinium Salts to 2-Aminobiphenyls
Fadda, A. A.,Sagitullin, R. S.
, p. 707 - 710 (2007/10/02)
N-Methyl-2-benzylpyridinium iodide (1c) undergoes ring opening and recyclization reactions when heated with methylammonium sulphite to give 2-methylaminobiphenyl (2c), 2-hydroxybiphenyl (3) and 2-benzylpyridine (4).A similar reaction of N-methyl-2-(p-acetylbenzyl)-, N-methyl-2-(p-acetamidobenzyl)-, N-methyl-2-(p-phthalimidobenzyl)-, N-methyl-2-(p-ethylaminobenzyl)-, N-methyl-2-(p-methylethylaminobenzyl)-, and N-methyl-2-butyl-pyridinium iodides (1e, g-k) affords 2-methylamino-4-acetylbiphenyl (2e), 2-methylamino-4-aminobiphenyl (2g = 2h), 2-methylamino-4-ethylaminobiphenyl (2i), 2-methylamino-4-methylethylaminobiphenyl (2j) and N-methyl-2-propylaniline (2k) respectively in good yields.On the other hand, N-methyl-2-(carbamylmethyl)- (1a), N-methyl-2-(cyanomethyl)- (1b) and N-methyl-2-(p-nitrobenzyl)pyridinium iodides (1d) do not undergo such a rearrangement.It has been found that the unquaternized 2-benzylpyridine when heated with methylammonium sulphite undergoes recyclization to 2-methylaminobiphenyl (2k).
