The Synthesis of Benzoyltaurin. 



407 



ju-phenylthiazolin. In the synthesis of benzoyltaurin use was 

 made of a buffer substance such as NaHC0 3 or NaOOCCH 3 

 instead of NaOH which was employed by Baum to neutralize the 

 HC1 which is set free during the course of the reaction. The pro- 

 cedure follows essentially the method used by Fischer 1 for the 

 benzoylation of other amino acids. 



Five grams of taurin in solution were shaken with 10 grams 

 of benzoyl chloride in the presence of sufficient NaHC0 3 to keep 

 the reaction slightly alkaline. The benzoylation was continued 

 until no nitrogen was obtained when a test portion was treated 

 with HN0 2 . The solution was made just acid by addition of 

 HC1, cooled in the ice chest and the benzoic acid was removed 

 by filtration. The filtrate was evaporated to dryness at a low 

 temperature and the residue was extracted with petroleum ether 

 to remove traces of benzoic acid. The residue was then extracted 

 with dry ethyl acetate in which solvent benzoyltaurin is slightly 

 soluble. Unlike hippuric acid and other benzoylated amino acids 

 benzoyltaurin is not easily crystallizable either in the free state 

 or as the sodium salt, hence purification is difficult. It is very 

 soluble in water and only slightly soluble in alcohol. Analysis of 

 our product gave the following values: 



Calculated for 

 Found. CeHsCOHNCHzCHzSOaNa. 



Nitrogen 5.5% 5.6% 



Sulfur : 13-4% 12.8% 



Sodium (as Na 2 S0 4 ) 9.8% 9.2% 



a-NH 2 0.3% 



TABLE I. 



The Simultaneous Administration of Sodium Benzoate and Taurin. 



















Conju- 







Total 



Total 



Neu- 



Total 



Free 



gated 





a- 



Sul- 



Sul- 



tral 



Nitro- 



Ben- 



Ben- 



Dose. 



NH2, 



fur. 



fates, 



Sul- 





gen, 



zoic 



zoic 





Mg. 



Gm. 



Gm. 



fur, 





Gm. 



Acid, 



Acid, 











Gm. 







Gm. 



Gm. 



Dog. No. 1. 





68 



0.152 



0.082 



0.070 





,8 







6 gm. taurin, 6.8 gm. benzoic 



















acid 



330 



I-I55 



0.092 



1.063 





3-5 



0.58 



5.82 





187 



0.260 



0.016 



0.144 





3-2 









7i 



0.144 



0.041 



0.103 





3-2 







Fischer, E., Berichte, 1899, xxxii, 2451. 



