Dichloromethane → Dimethyl 3-(2-bromoethylamino)-2-pentenedioate

HRID 231891Notes

Reaction equation

HRID 231891 reaction equation
CS([CH2:5][CH2:6][NH:7][C:8]([CH2:14][C:15]([O:17][CH3:18])=[O:16])=[CH:9][C:10]([O:12][CH3:13])=[O:11])(=O)=O.ClCCl.S([O-])(=O)(=O)C.[Br-:27].[Li+]>O>[Br:27][CH2:5][CH2:6][NH:7][C:8]([CH2:14][C:15]([O:17][CH3:18])=[O:16])=[CH:9][C:10]([O:12][CH3:13])=[O:11]

Participants

6

Reactant 4

HCID 6344DichloromethaneHCID 82050Lithium BromideHCID 85257MethanesulfonateHCID 74015715Dimethyl 3-(2-methanesulfonylethylamino)-2-pentenedioate

Product 1

HCID 74015712Dimethyl 3-(2-bromoethylamino)-2-pentenedioateYield 86.7%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
35 °C

Procedure

Dimethyl 3-(2-methanesulfonylethylamino)-2-pentenedioate (156.3 g, 529 mmol) was added to a 2 L three-neck flask, which was fitted with a mechanical stirrer, thermometer, and reflux condenser. Dichloromethane (750 mL) was added and stirred until the mesylate had completely dissolved, anhydrous lithium bromide (69.0 g, 794 mmmol) was added, and the mixture stirred at 35° C. for 19 hours. The mixture was cooled to 0° C. and water (250 mL) added, then stirred for 5 minutes and the phases separated. The organic phase was washed with water (3×250 mL) and brine (150 mL), and dried over anhydrous potassium carbonate for 15 minutes. Rotary evaporation of the solvent under reduced pressure (50° C.) gave 128.4 g of crude dimethyl 3-(2-bromoethylamino)-2-pentenedioate as a yellow oil, which quickly solidified to a yellow solid. The crude material was purified by extraction into boiling hexane (5×750 mL) and recrystallization from hexane, and the pot residues extracted and recrystallized, to give a total of 90.8 g (61.2% yield) of dimethyl 3-(2-bromoethylamino)-2-pentenedioate as white needles. An NMR spectrum in CDCl3 indicated an Z/E isomer ratio of 19:1, and remeasurement of the CDCl3 solution after three days indicated an Z/E ratio of 4:1. The two isomers were not separated.

Workup

  1. customwhich was fitted with a mechanical stirrer
  2. temperaturethermometer, and reflux condenser
  3. dissolutionhad completely dissolved
  4. temperatureThe mixture was cooled to 0° C.
  5. stirringstirred for 5 minutes
  6. customthe phases separated
  7. washThe organic phase was washed with water (3×250 mL) and brine (150 mL)
  8. dry with materialdried over anhydrous potassium carbonate for 15 minutes
  9. customRotary evaporation of the solvent under reduced pressure (50° C.)

Sources & evidence

ORD record
ord-4aa7d154b9934cf993aa465d95706722
Source dataset
uspto-grants-1989_07
Patent number
US04849526

Reaction notes

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