A process for making pure crystalline D-isoglutamyl-D-tryptophan is provided which includes the step of deprotecting essentially pure N-tert-butoxycarbonyl-D-isoglutamyl-D-tryptophan or its diester to yield essentially pure D-isoglutamyl-D-tryptophan. A process is also provided for the preparation of pure mono ammonium salt of D-isoglutamyl-D-tryptophan from essentially pure N-tert-butoxycarbonyl-D-isoglutamyl-D-tryptophan. D-isoglutamyl-D-tryptophan, ammonium salt (1:1) is a stable pharmaceutical solid.
提供了一种制备纯结晶D-异谷
氨酰-
D-色氨酸的过程,包括去保护基的步骤,将基本上纯的N-叔丁氧羰基-D-异谷
氨酰-
D-色氨酸或其二酯去保护,得到基本上纯的D-异谷
氨酰-
D-色氨酸。还提供了一种从基本上纯的N-叔丁氧羰基-D-异谷
氨酰-
D-色氨酸制备纯D-异谷
氨酰-
D-色氨酸单酰胺盐的过程。D-异谷
氨酰-
D-色氨酸铵盐(1:1)是一种稳定的药物固体。