Chemistry of the N'-Oxides of Nicotine and Myosmine

Abstract

Nicotine-N';-oxide (II) was purified to give a crystalline form which has m. p. 170_??_171°C, and [α]_??_=+65.3°C. The reaction of nicotine-N';-oxide with acetic anhydride afforded a good yield of l';-(3-pyridyl)-4';-(N';-acetylmethylamino)-l';-propanone (V) which was hydrolyzed to give pseudoöxynicotine (III). Nicotine-N';-oxide (II) either with acetyl chloride or with benzoyl chloride, under similar conditions, furnished pseudoöxynicotine (III) without giving the corresponding acyl compound as an intermediate. 2';-Methyl-6';-(3-pyridyl)-tetrahydro-l';, 2';-oxazine (XII) rearranged from nicotine-N';-oxide reacted neither with acetic anhydride nor acetyl chloride. Reduction of the oxime (IV) of pseudooxynicotine dihydrochloride gave dl-l';-amino-1';-(3-pyridyl)-4';-methyl-aminobutane (VII) as a main product. The hydrazone (VIII) of pseudoöxynicotine dihydrochloride subjected to a modification of the Wolf-Kischner reaction, was reduced to yield dihydrometanicotine (IX). The pyrolysis of N';-methylmyosmine (IV) gave N';-methylnicotinamide (XI) and nicotyrine (X) in low yields. The presence of N';-methylmyosmine in the autoxidation mixture of nicotine was also established. Oxidation of nornicotine (XIV) with hydrogen peroxide furnished myosmine-N';-oxide (XV) whose identity was established by its chemical and physical properties. This oxide, on pyrolysis, gave nornicotyrine (XVII) and myosmine (XVI).