Carbon Tetrachloride → Methyl 3-chloro-1H-pyrrole-2-carboxylate

Temperature

0 °C

To a solution of 5-methyl-3,4-dihydro-2H-pyrrole (2.50 g, 30.0 mmol) in CCl4 (100 mL) was added N-chlorosuccinimide (32.00 g, 240 mmol), and the mixture was then heated to reflux for 72 hours. The reaction mixture was cooled to 0° C. The formed precipitate was filtered off, and the filtrate was concentrated under reduced pressure. The residue was dissolved in methanol (100 mL), followed by the addition of sodium methoxide (9.80 g, 180 mmol). The resulting suspension was heated to reflux and stirred for 1.5 h. The solvent was evaporated, and the residue was suspended in ether. The solid was filtered off, and the filtrate was concentrated under reduced pressure. The residue was dissolved in DCM (100 mL) and 2 M HCl (100 mL). The biphasic solution was stirred for 10 min. The organic layer was separated, dried over MgSO4, filtered and evaporated. The crude oil was subjected to chromatography purification on silica gel eluting with EtOAc and Hexanes to afford the title compound (2.5 g, 52%) as an orange solid. MS (ES+) C6H6ClNO2 requires: 159. found: 160 [M+H]+.

1. temperaturethe mixture was then heated
2. temperatureto reflux for 72 hours
3. filtrationThe formed precipitate was filtered off
4. concentrationthe filtrate was concentrated under reduced pressure
5. dissolutionThe residue was dissolved in methanol (100 mL)
6. temperatureThe resulting suspension was heated
7. temperatureto reflux
8. customThe solvent was evaporated
9. filtrationThe solid was filtered off
10. concentrationthe filtrate was concentrated under reduced pressure
11. dissolutionThe residue was dissolved in DCM (100 mL)
12. stirringThe biphasic solution was stirred for 10 min
13. customThe organic layer was separated
14. dry with materialdried over MgSO4
15. filtrationfiltered
16. customevaporated
17. customThe crude oil was subjected to chromatography purification on silica gel eluting with EtOAc and Hexanes

ORD record

ord-962bb37a2da54648bbe2fb7f077d2d01

Source dataset

uspto-grants-2015_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09200002B2