Am.  Jour.  Pljarin. 
Aug.,  1892. 
Digitalin. 
425 
formula  C29H^On,  or  that  of  a  hydride  of  digitalin.  Professor 
Boehm  has  made  trial  of  it  and  found  that  it  is  entirely  inert. 
Note  on  the  Preparation  of  Digitogenin. — The  transformation  of 
digitonin  into  digitogenin,  dextrose,  and  galactose,  by  treatment 
with  hydrochloric  acid1  takes  place  as  already  pointed  out2  in  a 
comparatively  definite  manner.  It  is,  however,  subject  to  the  dis- 
advantage, especially  when  operating  upon  a  large  quantity,  that 
the  digitogenin  separates  in  an  amorphous  condition,  and  is,  there- 
fore, very  difficult  to  wash  out  and  dry  before  it  can  be  brought  into 
a  crystalline  condition  by  means  of  chloroform  or  alcohol.  There 
is  also  a  possibility  that  the  separated  digitogenin  may  be  con- 
taminated either  with  portions  of  digitonin  or  with  the  first  product 
of  its  transformation,  digitoresin,  either  of  which  would  thus  escape 
complete  decomposition. 
The  favorable  results  obtained  in  the  transformation  of  digitalin 
in  an  alcoholic  solution,  therefore,  induced  me  to  make  a  trial  of 
the  same  method  with  digitonin.  The  result  was  very  satisfactory; 
but  to  ensure  success  strong  alcohol  must  be  used,  and  the  heating 
must  be  continued  for  a  long  time.  Experiments  made  by  Sanda 
showed  that  the  following  is  the  best  method  of  operating : 
A  mixture  of  digitonin  (C27Hi6Ou  -f  5H20)  with  8  parts  of  93 
per  cent,  alcohol,  and  2  parts  concentrated  hydrochloric  acid  (1*19) 
is  heated  for  an  hour  and  a  half  in  a  boiling  water-bath  under  a 
reflux  condenser.  The  whole  is  then  allowed  to  cool  slowly,  and 
gradually  the  whole  liquid  becomes  filled  with  warty  masses  of 
digitogenin.  This  deposit  is  separated  by  a  suction  pump,  washed 
with  80  per  cent,  alcohol  and  pressed  dry.  It  amounts  to  from  23 
to  27  per  cent,  of  the  glucoside  operated  upon.  For  conversion 
into  digitogenic  acid  it  requires  no  further  purification.  A  further 
quantity  may  be  obtained  from  the  filtrate  from  this  first  crystalliza- 
tion. For  that  purpose  the  liquid  is  mixed  with  calcium  carbonate 
until  effervescence  ceases,  the  greater  part  of  the  alcohol  is  then 
distilled  off,  the  residue  diluted  with  water  and  shaken  out  with 
chloroform.  The  chloroform  solution  is  freed  from  water  by 
sodium  sulphate,  chloroform  distilled  off,  and  the  residue  of  impure 
digitogenin  is  crystallized  from  93  per  cent,  alcohol.    About  5  per 
1  Berichte,  xxiii,  1555. 
3  Berichte,  xxiv,  3951. 
