Oxalyl chloride → methyl 2-(5,6-dihydro-4H-pyrrolo[3,2,1-ij]quinolin-1-yl)-2-oxoacetate

Temperature

0 °C

To a solution of 5,6-Dihydro-4H-pyrrolo[3,2,1-ij]quinoline (1.67 g, 10.6 mmol) in 150 mL of anhydrous diethyl ether at 0° C. was added dropwise oxalyl chloride (1.05 mL, 12.08 mmol) and the resulting solution was stirred at 0° C. for 40 minutes. The mixture was then cooled to −78° C. and sodium methoxide (42 mL, 21 mmol, 0.5 M in methanol) was added slowly. Upon completion of the addition, the dry ice bath was removed and the reaction was warmed to 20-24° C. over 2 hours. The mixture was diluted with ethyl acetate (200 mL), washed with water (100 mL) and the layers were separated. The organic layer was washed with saturated aqueous sodium chloride (50 mL), dried over sodium sulfate, filtered and concentrated in vacuo. The residue was dissolved in ethyl acetate (100 mL), filtered through a 2 inch plug of coarse silica gel and concentrated in vacuo to give 2.16 g (84%) of the desired compound as a yellow solid.

1. temperatureThe mixture was then cooled to −78° C.
2. additionUpon completion of the addition
3. customthe dry ice bath was removed
4. temperaturethe reaction was warmed to 20-24° C. over 2 hours
5. additionThe mixture was diluted with ethyl acetate (200 mL)
6. washwashed with water (100 mL)
7. customthe layers were separated
8. washThe organic layer was washed with saturated aqueous sodium chloride (50 mL)
9. dry with materialdried over sodium sulfate
10. filtrationfiltered
11. concentrationconcentrated in vacuo
12. dissolutionThe residue was dissolved in ethyl acetate (100 mL)
13. filtrationfiltered through a 2 inch plug of coarse silica gel
14. concentrationconcentrated in vacuo

ORD record

ord-20b20bd9c51d44499574ea2fc7ee9a76

Source dataset

uspto-grants-2004_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06743785B2