Pyridine → Ethyl 3-oxo-4-(pyridin-4-yl)butanoate

A solution of pyridin-4-yl-acetic acid hydrochloride salt (1.73 g 10 mmol) in CH2Cl2 (50 mL) was treated with triethylamine (2.09 mL, 15 mmol), followed by 1,1′-carbonyldiimidazole (2.43 g, 15 mol). After 4 h, the solution was added dropwise to a 0° C. solution of 2,2-dimethyl-[1,3]dioxane-4,6-dione (Meldrum's acid; 1.73 g, 12 mmol) and pyridine (1.63 mL, 20 mmol) in CH2Cl2 (50 mL). The reaction mixture was allowed to warm slowly to rt and was stirred for 18 h. The mixture was washed with H2O (2×), and the organic layer was dried and concentrated. The crude residue was dissolved in EtOH (100 mL) and heated at reflux for 4 h. The mixture was allowed to cool to rt and was concentrated. The residue was purified by chromatography (EtOAc/hexanes) to give the title compound (411 mg, 15%) as a pale yellow oil. MS (ESI): mass calcd. for C11H13NO3, 207.1; m/z found, 208.1 [M+H]+. 1H NMR (CDCl3): 8.57 (dd, J=4.4, 1.6, 2H), 7.16 (dd, J=4.4, 1.6, 2H), 4.20 (q, J=7.2, 2H), 3.88 (s, 2H), 3.51 (s, 2H), 1.28 (t, J=7.2, 3H).

1. washThe mixture was washed with H2O (2×)
2. customthe organic layer was dried
3. concentrationconcentrated
4. dissolutionThe crude residue was dissolved in EtOH (100 mL)
5. temperatureheated
6. temperatureat reflux for 4 h
7. temperatureto cool to rt
8. concentrationwas concentrated
9. customThe residue was purified by chromatography (EtOAc/hexanes)

ORD-Eintrag

ord-77547fa49ba547068d9bdcfba6788117

Quelldatensatz

uspto-grants-2013_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08415366B2