Hydrochloric Acid → N-(N-Formyl-L-alpha-aspartyl)-3-phenyl-L-alanine

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Reaction Steps

To 200 ml of water, 50% caustic solution is added to adjust the pH to 9.5. To the aqueous solution, L-phenylalanine (30 g, 0.181 mole) is dissolved while adding 11.8 ml of 50% caustic solution. After cooling the resultant solution to between -3° C. to +3° C., 14.5 ml of 50% caustic solution and formyl-L-aspartic anhydride (28.6 g, 0.199 mole) is added over a 1 hour period and the resulting reaction mixture is stirred for 1/2 hour at between -3° C. to 3° C. Upon lowering the pH of the mixture using 34.4 ml of hydrogen chloride, a solid precipitate is produced and it is separated by filtration. The precipitate is dried to obtain the desired formyl-α-L-aspartyl-L-phenylalanine (42.6 g, 0.138 mole). The remaining filtrate is collected and acidified to a pH of 6.0 with 9.4 ml of concentrated hydrogen chloride to produce the precipitate. The precipitate is filtered and dried to obtain additional formyl-α-L-aspartyl-L-phenylalanine (2.9 g, 0.009 mole). TLC analysis shows that there is no trace of β-isomer.

Provenance & Evidence