Phosphorus oxychloride → 8-Chloro-3-methoxy-1,7-naphthyridine

Temperature

85 °C

To a mixture of 3-methoxy-1,7-naphthyridin-8(7H)-one (4.50 g, 25.5 mmol) in acetonitrile (102 ml) was added phosphorus oxychloride (11.69 ml, 128 mmol). The reaction mixture was heated to 85° C. for 5 h. The solution was cooled to rt and concentrated in vacuo. The resulting brown residue was partitioned between CH2Cl2 and aqueous saturated NaHCO3 solution; the aqueous layer was back-extracted with DCM (3×). The combined organic extracts were dried over sodium sulfate, the filtrate was concentrated in vacuo, and the residue was purified by silica gel chromatography (5%-30% of 9:1 DCM:MeOH in DCM) to afford 8-chloro-3-methoxy-1,7-naphthyridine (3.00 g, 15.41 mmol, 60.3% yield) as an off-white solid. MS m/z=195 (M+H).

1. temperatureThe solution was cooled to rt
2. concentrationconcentrated in vacuo
3. customThe resulting brown residue was partitioned between CH2Cl2 and aqueous saturated NaHCO3 solution
4. extractionthe aqueous layer was back-extracted with DCM (3×)
5. dry with materialThe combined organic extracts were dried over sodium sulfate
6. concentrationthe filtrate was concentrated in vacuo
7. customthe residue was purified by silica gel chromatography (5%-30% of 9:1 DCM:MeOH in DCM)

ORD record

ord-efa6cbf931b3456299b557293e06c52e

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09296734B2