352 
Urinary  Antisepsis. 
Am.  Tour.  Pharm. 
May,  19 1 8. 
as  urinary  antiseptics,  since  the  only  one  showing  antiseptic  strength 
in  urine  fails  to  be  excreted. 
Halogen  Derivatives  of  Sulphonephthaleins. 
To  illustrate  the  chemical  structure  of  the  halogen  derivatives  of 
sulphonephthaleins  investigated,  the  structural  formula  (Fig.  2)  is 
given.  Those  investigated  were  tetrabromphenolsulphonephthalein, 
tetrachlorphenolsulphonephthalein,  di-iodophenolsulphonephthalein, 
dibromcresolsulphonephthalein  and  dibromthymolsulphonephthalein. 
These  compounds,  all  used  in  the  form  of  the  sodium  salt,  show 
moderate  germicidal  ability  in  water,  probably  owing  to  excess  alkali 
necessary  to  bring  them  into  solution ;  but  they  all  become  inert  in 
Br 
/<^>0H 
\_/      \  Br 
S03Na      \/  \__ 
\— /"° 
Br 
Fig.  2.    Tetrabromphenolsulphonephthalein  (monosodium  salt). 
urine.  Furthermore,  none  of  them  excepting  tetrachlorphenolsul- 
phonephthalein  are  excreted,  and  we  therefore  have  in  compounds 
of  this  class  a  definite  relationship  between  chemical  structure  and 
"  renal  affinity." 
Conclusions. — 1.  Substitution  of  bromine  in  compounds  of  the 
sulphonephthalein  type  prevents  excretion  by  the  kidney. 
2.  Halogenated  sulphonephthaleins  give  no  promise  of  value  as 
urinary  antiseptics. 
Phthaleins. 
These  differ  from  sulphonephthaleins  in  that  a  carboxyl  group 
replaces  the  sulphonic  acid  group,  as  shown  in  the  formula  (Fig.  3). 
Those  investigated  were  phenolphthalein,  thymolphthalein,  tetra- 
bromtetrachlorphenolphthalein  tetraiodophenolphthalein,  phenol- 
tetrachlorphthalein  and  sulphonated  phenolphthalein.  None  of 
these  compounds  were  antiseptic  in  urine,  nor  were  any  of  them 
excreted  by  the  kidney,  excepting  the  sulphonated  phenolphthal- 
ein.    It  is  interesting  to  note  that  the  sulphonation  of  phenol- 
