Sodium Acetate → methyl N-(2-bromoethyl)-3-methoxycarbonyl-2-pyrroleacetate

Temperature

0 °C

Sodium acetate (41.0 g, 500 mmol) was added to the 2-bromoacetaaldehyde solution, and stirred for 5 minutes, at which point the solution had a pH of 6. The flask was placed in a cool tap water bath and dimethyl 3-(2-bromoethylamino)-2-pentenedioate (20.0 g, 71 mmol) was added, followed by isopropanol (40 mL), and the solution was stirred at room temperature (25° C.). Within about 35 minutes, all the solids had dissolved, and a precipitate started forming within 90 minutes. Stirring was continued at room temperature for 20 hours, and the solution then cooled to 0° C. and stirred at that temperature for 1 hour, then filtered through a coarse frit. The precipitate was washed with ice-cold water (400 mL) and ice-cold isopropanol (150 mL) and dried, to give 15.7 g (72% yield) of crude methyl N-(2-bromoethyl)-3-methoxycarbonyl-2-pyrroleacetate as a light tan solid, m.p. 129°-130.5° C., NMR (CDCl3): δ:

1. customThe flask was placed in a cool tap water bath
2. stirringthe solution was stirred at room temperature (25° C.)
3. waitWithin about 35 minutes
4. dissolutionall the solids had dissolved
5. customa precipitate started forming within 90 minutes
6. stirringStirring
7. waitwas continued at room temperature for 20 hours
8. stirringstirred at that temperature for 1 hour
9. filtrationfiltered through a coarse frit
10. washThe precipitate was washed with ice-cold water (400 mL) and ice-cold isopropanol (150 mL)
11. customdried

ORD record

ord-dcfae7b7dddb403bbedddbb322699475

Source dataset

uspto-grants-1989_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04835288