Hydrochloric Acid → alpha-Acetamido-6-chloro-3-indoleacrylic acid methylester

HRID 1447313Notes

Reaction equation

HRID 1447313 reaction equation
Cl.[CH3:2][O:3][C:4](=[O:18])[C:5]([NH2:17])=[CH:6][C:7]1[C:15]2[C:10](=[CH:11][C:12]([Cl:16])=[CH:13][CH:14]=2)[NH:9][CH:8]=1.N1C=CC=CC=1.Cl.[C:26](OC(=O)C)(=[O:28])[CH3:27]>>[CH3:2][O:3][C:4](=[O:18])[C:5]([NH:17][C:26](=[O:28])[CH3:27])=[CH:6][C:7]1[C:15]2[C:10](=[CH:11][C:12]([Cl:16])=[CH:13][CH:14]=2)[NH:9][CH:8]=1

Participants

5

Reactant 4

HCID 313Hydrochloric AcidHCID 1049PyridineHCID 7918Acetic AnhydrideHCID 70550909Alpha-amino-6-chloro-3-indoleacrylic acid methylester hydrochloride

Product 1

HCID 54310075alpha-Acetamido-6-chloro-3-indoleacrylic acid methylesterYield 90%

Procedure

A 1-l. three-necked flask, equipped with a thermometer, a mechanical stirrer and a dropping funnel was charged with 101.2 g (ca. 0.35 moles) of crude pulverized alpha-amino-6-chloro-3-indoleacrylic acid methylester hydrochloride and 400 ml of acetic anhydride. The slurry was cooled to 15°. Then 32 g (0.40 moles) of pyridine was added with stirring over a 5 minute period, while the temperature was kept between 15° and 22°; after complete addition, virtually all starting hydrochloride went into solution. Stirring at 22° was continued for 20 minutes during which the product began to crystallize out. 200 ml of water was then added over 40 minutes, keeping the temperature at ca. 25°. Stirring at this temperature was continued for 11/2 hours. 900 ml of water was then added over 5 minutes and the slurry stirred at room temperature for an additional hour. The precipitate was collected by suction filtration, washed with 750 ml of water and dried at 60° (constant weight) to afford 92.9 g (90%) of product, as yellow crystals, m.p. 202°-203°.

Workup

  1. customthree-necked flask, equipped with a thermometer, a mechanical stirrer and a dropping funnel
  2. additionwas charged with 101.2 g (ca. 0.35 moles) of crude
  3. temperatureThe slurry was cooled to 15°
  4. customwas kept between 15° and 22°
  5. additionafter complete addition
  6. stirringStirring at 22°
  7. waitwas continued for 20 minutes during which
  8. customto crystallize out
  9. addition200 ml of water was then added over 40 minutes
  10. customat ca. 25°
  11. stirringStirring at this temperature
  12. custom2 hours
  13. addition900 ml of water was then added over 5 minutes
  14. stirringthe slurry stirred at room temperature for an additional hour
  15. filtrationThe precipitate was collected by suction filtration
  16. washwashed with 750 ml of water
  17. customdried at 60° (constant weight)

Sources & evidence

ORD record
ord-40df03da71f44f949770be60102ab58e
Source dataset
uspto-grants-1982_02
Patent number
US04316847

Reaction notes

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