Dimethylformamide → 2-Methoxy-5-(methoxymethoxy)-4-pyridinecarboxaldehyde

Temperatur

0 °C

To a mixture of 2-methoxy-5-(methoxymethoxy)pyridine (30 g, 0.178 mol, 1 eq.) and diisopropylamine (507 uL, 3.6 mmol, 0.02 eq.) in THF (500 mL) was added methyl lithium (1.6 M/THF, 200 mL, 0.32 mol, 1.8 eq.) at −40° C. Upon the completion of addition, the mixture was warmed to 0° C., continued to stir at 0° C. for 3 h, cooled back down to −40° C. and added DMF (24.7 mL, 0.32 mol, 1.8 eq.) slowly. The mixture was then stirred at −40° C. for 1 h, quenched with a mixture of HCl (12 N, 120 mL) and THF (280 mL), warmed to rt, and added water (200 mL). The pH of the mixture was adjusted to pH 8-9 with solid K2CO3. The aqueous layer was extracted with EtOAc (300 mL) twice. The combined organic layers were dried over Na2SO4 and concentrated to give 2-methoxy-5-(methoxymethoxy)isonicotinaldehyde (33.5 g, 95.7%) as a brown solid, which was used for next step without further purification. 1H NMR (400 MHz; CD3OD) 7.90 (s, 1H), 6.92 (s, 1H), 5.64 (s, 1H), 5.20 (s, 2H), 3.84 (s, 3H), 3.48 (s, 3H). LRMS (M+H+) m/z 198.1

1. additionUpon the completion of addition
2. temperaturecooled back down to −40° C.
3. stirringThe mixture was then stirred at −40° C. for 1 h
4. customquenched with a mixture of HCl (12 N, 120 mL) and THF (280 mL)
5. temperaturewarmed to rt
6. additionadded water (200 mL)
7. extractionThe aqueous layer was extracted with EtOAc (300 mL) twice
8. dry with materialThe combined organic layers were dried over Na2SO4
9. concentrationconcentrated

ORD-Eintrag

ord-b0bba97095904f7c9a6e8a401af1c406

Quelldatensatz

uspto-grants-2015_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09012450B2