Methyl chloroformate → Methyl 2-chloro-7,8-dihydro-1,6-naphthyridine-6(5H)-carboxylate

To a solution of 2-chloro-5,6,7,8-tetrahydro-[1,6]naphthyridine hydrochloride (1.54 g, 7.5 mmol) in DCM (25 mL) was added Et3N (3.1 mL, 22 mmol). After the addition and stirring at room temperature for 5 min, the solution was cooled to 0° C., followed by the addition of methylchloroformate (0.85 mL, 11 mmol). The resulting reaction mixture was then allowed to stir at room temperature for 2 hours. It was then washed with satd. aq. NaHCO3 solution and brine. The organic layer was dried over anhy. Na2SO4, filtered and concentrated in vacuo to give a crude product. Flash column chromatography separation (silica gel, 40 g, 30% EtOAc in hexane) then afforded the tile compound (1.53 g, 90%) as a white solid. MS: 227.3 (M+H+).

1. additionAfter the addition
2. temperaturethe solution was cooled to 0° C.
3. customThe resulting reaction mixture
4. stirringto stir at room temperature for 2 hours
5. washIt was then washed with satd
6. customThe organic layer was dried over anhy
7. filtrationNa2SO4, filtered
8. concentrationconcentrated in vacuo
9. customto give a crude product
10. customFlash column chromatography separation (silica gel, 40 g, 30% EtOAc in hexane)

ORD record

ord-c5d2d3cdb610413083b3604ef87fa839

Source dataset

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09133158B2