Hydrogen Bromide → 6-chloro-L-tryptophan

HRID 616262Notes

Reaction equation

HRID 616262 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 4N 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-3d12bec7184442f3959b844d35772bd4
Source dataset
uspto-grants-1978_02
Patent number
US04073795

Reaction notes

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