Water → 3-(2-Methyl-5-pyridinyl)-2-cyclohexen-1-one

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Reaction Steps

A 72.2 g. portion of 1-(2-methyl-5-pyridinyl)hexan-1,5-dione was dissolved in 200 ml. of methanol and added to a solution containing 50 g. of sodium hydroxide in 500 ml. of water plus 100 ml. of methanol. The reaction mixture was stirred for 1 hour at room temperature and the methanol was then distilled off in vacuo at a low temperature. The remaining aqueous mixture was extracted four times with ether; the ether extracts were combined, dried over anhydrous sodium sulfate and filtered; and, the dried ether solution was stripped in vacuo to remove the ether and to yield 54 g. (82% yield) of 3-(2-methyl-5-pyridinyl)-2-cyclohexen-1-one. This 54 g. portion of 2-(2-methyl-5-pyridinyl)-2-cyclohexen-1-one was converted, as in Example C-3, to 36.0 g. (62% yield) of the corresponding oxime derivative, m.p. 171°-173° C. The 10 g. portion of this oxime was converted, as in Example D- 3, to 6.4 g. of 5-(3-aminophenyl)-2-methylpyridine, m.p. 115°-116° C., using 8.5 ml. of acetic anhydride and 70 ml. of acetic acid and gaseous hydrogen chloride for 1 hour while heating the reaction mixture at 80°-90° C.

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