Methanol → methyl (2R)-2-amino-3-(1H-indol-3-yl)propanoate hydrochloride
Reaction equation
[NH2:1][C@@H:2]([C:13]([OH:15])=[O:14])[CH2:3][C:4]1[C:12]2[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=2)[NH:6][CH:5]=1.S(Cl)([Cl:18])=O.[CH3:20]O>>[ClH:18].[CH3:20][O:14][C:13](=[O:15])[C@@H:2]([CH2:3][C:4]1[C:12]2[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=2)[NH:6][CH:5]=1)[NH2:1]Participants
4
Conditions
- Temperature
- 2.5 °C
Procedure
D-tryptophan (100 g) was suspended in methanol (500 mL) and the suspension added to a solution of thionyl chloride (82.14 g) in methanol (500 mL) at 25-30° C. under nitrogen atmosphere. The resultant solution was stirred at reflux for 3 to 4 hours and the reaction mixture was concentrated to a residual volume of 150 mL. To the concentrated mixture dichloromethane (700 mL) was added and the resultant solution was cooled to 0-5° C. with continuous stirring for 0.5 hours. The solid so obtained was filtered, washed with dichloromethane (200 mL) and dried in air at 40-45° C. to afford D-tryptophan methyl ester hydrochloride.
Workup
- temperatureat reflux for 3 to 4 hours
- concentrationthe reaction mixture was concentrated to a residual volume of 150 mL
- additionTo the concentrated mixture dichloromethane (700 mL) was added
- customThe solid so obtained
- filtrationwas filtered
- washwashed with dichloromethane (200 mL)
- customdried in air at 40-45° C.
Sources & evidence
- ORD record
- ord-2f1b723c503d4ab5a0e681f29d6600e7
- Source dataset
- uspto-grants-2013_05
- Patent number
- US08445698B2
Reaction notes
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