4-Acetylpyridine → 4-Acetylpyridine-N-oxide

In a manner analogous to the preparation of the compound of Example 1, from 3,4,5-trimethoxyphenylguanidine nitrate (2.25 g, 7.81 mmol), 3-dimethylamino-1-(1-oxo-pyrid-4-yl)-2-propen-1-one (880 mg, 7.81 mmol) and sodium hydroxide (344 mg, 8.6 mmol) to give the title compound (1.2 g) as a green solid m.p. 220°. MS m/z 355 (M+H). The 3-dimethylamino-1-(1-oxopyrid-4-yl)-2-propen-1-one used as starting material was prepared by heating a solution of 4-acetylpyridine-N-oxide (2.5 g, 18.2 mmol) in dimethylformamide diethylacetal (30 ml) at reflux for 0.5 h. On cooling the resulting solid was collected and washed with diethyl ether to give the desired product (3.18 g) as an orange solid m.p. 181°. The 4-acetylpyridine-N-oxide was prepared by treating a solution of 4-acetylpyridine (3.0 g, 24.8 mmol) in CH2Cl2 with 3-chloro-peroxybenzoic acid [Aldrich 57-86%] (8.4 g) at room temperature for 12 h. The reaction was filtered, the filtrate concentrated under reduced pressure and the resulting residue subjected to column chromatography [silica 10% methanol-ethyl acetate] to give the desired product (3.2 g) as a white solid m.p. 101°.

1. filtrationThe reaction was filtered
2. concentrationthe filtrate concentrated under reduced pressure

ORD-Eintrag

ord-227636305fa04ee993f927fc24087bb6

Quelldatensatz

uspto-grants-1999_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05958935