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73-22-3

2899-28-7

Preparation of Example 10 Ethyl L-tryptophan hydrochloride: L-tryptophan (14.3 g, 0.07 mol) was dissolved in 200 ml of ethanol containing about 7 g of anhydrous hydrogen chloride and the reaction was carried out at reflux for 5 hours. After completion of the reaction, the mixture was cooled and the precipitated solid was purified by recrystallization through ethanol/ether solvent mixture. The product was obtained as 17.4 g in 92.5% yield with the expected melting point. The product was chemically named ethyl L-2-amino-3-indolepropionate hydrochloride.