Hydrogen Bromide → 6-chloro-L-tryptophan

HRID 127494Notes

Reaction equation

HRID 127494 reaction equation
C([O:3][C:4]([C:6]1(C(OCC)=O)[CH2:10][C:9]([C:11]2[CH:16]=[CH:15][C:14]([Cl:17])=[CH:13][C:12]=2[NH2:18])=[CH:8][N:7]1C(=O)C)=[O:5])C.Br>>[Cl:17][C:14]1[CH:13]=[C:12]2[C:11](=[CH:16][CH:15]=1)[C:9]([CH2:10][C@@H:6]([C:4]([OH:3])=[O:5])[NH2:7])=[CH:8][NH:18]2

Participants

3

Reactant 2

HCID 260Hydrogen BromideHCID 128785021-Acetyl-4-(2-amino-4-chlorophenyl)-2,3-dihydro-1H-pyrrole-2,2-dicarboxylic acid diethylester

Product 1

HCID 100626936-chloro-L-tryptophanYield 91.1%

Procedure

A mixture of 60 g (0.16 mol) of the compound of Example 11, and 450 ml. of 2 N aqueous HBr was heated under N2 at 95° for 30 hours. The solution was concentrated in vacuo and the residual salt was taken up in 300 ml of water. The solution was brought to pH 5.5 with 4 N NaOH and the mixture was chilled in an icebath for 1 hour. The precipitate was collected, washed with cold water and dried to give 34.8 g of product. Crystallization from glacial acetic acid (360 ml.) afforded, after drying at 100°/0.2 mmHg, 30.8 g (82%) of white crystals, m.p. 280° (dec.) (lit. m.p. 285°-286°), which was identical with an authentic sample.

Workup

  1. concentrationThe solution was concentrated in vacuo
  2. temperaturethe mixture was chilled in an icebath for 1 hour
  3. customThe precipitate was collected
  4. washwashed with cold water
  5. customdried

Sources & evidence

ORD record
ord-dee9d4792c1241bba8fcf348e4dc0575
Source dataset
uspto-grants-1981_03
Patent number
US04256641

Reaction notes

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