5-氯磺酰基-2-羟基苯甲酸 、
5[(9H-fluoren-9-ylmethoxycarbonylamino)methyl]-thiophene-3-carboxylic acid 、 alkaline earth salt of/the/ methylsulfuric acid 以15.6 mg的产率得到(S)-5-{[4-(1-carboxymethyl-2-oxo-ethylcarbamoyl)thiophen-2-ylmethyl]sulfamoyl}-2-hydroxy-benzoic acid