Sodium Hydroxide → 2-(2,3-Dihydro-[1,4]dioxino[2,3-b]pyridin-6-yl)acetic acid

To methyl 2-(2,3-dihydro-[1,4]dioxino[2,3-b]pyridin-6-yl)acetate (5.50 g, 25.1 mmol) in methanol (100 mL) was added aqueous 1N NaOH (50.2 mmol). The reaction was stirred at room temperature for 1 hour. The reaction mixture was concentrated and water (200 mL) was added. The aqueous solution was washed with 2-methyl-THF (2×200 mL). The aqueous layer was adjusted to pH˜5 and was concentrated. The resulting solids were suspended in chloroform (200 mL) and the mixture was heated to reflux with stirring. The mixture was heated at reflux for 10 minutes and was filtered while hot. The resulting filtrate was concentrated in vacuo to afford 2-(2,3-dihydro-[1,4]dioxino[2,3-b]pyridin-6-yl)acetic acid (SM-1aj, 2.5 g, 57%). MS (ES+) 196.2 (M+H)+. 1H NMR (CDCl3) δ 3.23 (s, 2H), 4.14 (s, 2H), 4.30 (s, 2H), 6.77 (d, 1H), 7.08 (d, 1H).

1. concentrationThe reaction mixture was concentrated
2. additionwater (200 mL) was added
3. washThe aqueous solution was washed with 2-methyl-THF (2×200 mL)
4. concentrationwas concentrated
5. temperaturethe mixture was heated
6. temperatureto reflux
7. stirringwith stirring
8. temperatureThe mixture was heated
9. temperatureat reflux for 10 minutes
10. filtrationwas filtered while hot
11. concentrationThe resulting filtrate was concentrated in vacuo

ORD-Eintrag

ord-ea7213897d0540aaa4d2b63a2adda051

Quelldatensatz

uspto-grants-2013_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08609680B2