Cesium carbonate → 5-Chloro-2-(2,3-dimethoxypropoxy)-6-(1-hydroxy-1,3-dihydrobenzo[c][1,2]oxaborol-5-yloxy)nicotinonitrile

Temperatur

50 °C

Into a 50-mL 3-neck-bottle purged and maintained with an inert atmosphere of nitrogen were placed a solution of 5,6-dichloro-2-(2,3-dimethoxypropoxy)nicotinonitrile (1.40 g, 4.59 mmol, 1.00 equiv, 95%) in DMSO (20 mL), benzo[c][1,2]oxaborole-1,5(3H)-diol (800 mg, 5.07 mmol, 1.10 equiv, 95%) and Cs2CO3 (1.88 g, 5.78 mmol, 1.20 equiv). The resulting solution was stirred for 2 h at 50° C. in an oil bath. The reaction mixture was then cooled and quenched by the addition of 20 mL of water. The resulting solution was extracted with 3×20 mL of ethyl acetate. The organic layers were combined, dried and concentrated under vacuum. The residue was applied onto a silica gel column and eluted with EtOAc/petroleum ether (1:5). This resulted in 1.09 g (57%) of 5-chloro-2-(2,3-dimethoxypropoxy)-6-(1-hydroxy-1,3-dihydrobenzo[c][1,2]oxaborol-5-yloxy)nicotinonitrile as a white solid. LC-MS (ES, m/z): 405 [M+H]+. 1H-NMR (300 MHz, DMSO-d6) δ (ppm) 9.27 (1H, m); 8.61 (1H, m); 7.82 (1H, d, J=8.1 Hz); 7.34 (1H, m); 7.26 (1H, m); 5.00 (2H, s); 4.12-4.17 (1H, m); 3.97-4.03 (1H, m); 3.25-3.30 (1H, m); 3.17 (6H, s).

1. customInto a 50-mL 3-neck-bottle purged
2. temperaturemaintained with an inert atmosphere of nitrogen
3. temperatureThe reaction mixture was then cooled
4. customquenched by the addition of 20 mL of water
5. extractionThe resulting solution was extracted with 3×20 mL of ethyl acetate
6. customdried
7. concentrationconcentrated under vacuum
8. washeluted with EtOAc/petroleum ether (1:5)
9. customThis resulted in 1.09 g (57%) of 5-chloro-2-(2,3-dimethoxypropoxy)-6-(1-hydroxy-1,3-dihydrobenzo[c][1,2]oxaborol-5-yloxy)nicotinonitrile as a white solid

ORD-Eintrag

ord-b7f1a41a77444f8eb28e05927f5a36c5

Quelldatensatz

uspto-grants-2014_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08716478B2