A colorless liquid with sweet, nutty, popcorn-like aroma.
It is purified by dissolving in HCl, extracting with Et2O to remove the possible impurity of nicotinic acid, basified with NaOH and extracted with Et2O. The dried extract is filtered, evaporated and the residual oil is distilled. If the NMR spectrum indicates further impurities, then convert it to the phenylhydrazone (m 137o, yellow needles from EtOH). This is hydrolysed with HCl [Engler & Kiby Chem Ber 22 597 1889], the phenylhydrazine HCl is removed by filtration, NaNO2 is added, the solution is basified with aqueous NaOH and extracted with Et2O as before and distilled at atmospheric pressure to give 3-acetylpyridine as a colourless oil. Purification can also be achieved by shaking with 50% aqueous KOH, extracting with Et2O, drying the extract and distilling it at atmospheric pressure or in vacuo. [Kloetzel & Chubb J Am Chem Soc 79 4226 1957.] The hydrochloride has m 180-181o (from MeOH/EtOH), the picrate has m 133.8-134.8o (from H2O), and the phenylhydrazone has m 137o (129-130o)(needles, from EtOH) [Webb & Webb J Am Chem Soc 71 2285 1949]. The ketoxime has m 112o (from EtOH or *C6H6). [Strong & McElvain J Am Chem Soc 55 816 1933, Kolloff & Hunter J Am Chem Soc 63 490 1941, Beilstein 21/7 V 394.]
Reported uses (ppm): (FEMA, 1994)
Reported found in roasted filberts, beer, brandy, coffee, malt and wheaten bread.
CoE: Used provisionally. Bev.: 2 ppm; Food: 3 ppm
FDA (other): n/a
JECFA: ADI: Acceptable. No safety concern at current levels of intake when used as a flavoring agent (2004).
clear colorless to yellow liquid