32 
Chlor  acetones. 
Am.  Jour.  Pharm. 
Jan.,  1888. 
NH2,  which  when  distilled  with  potash  yields  methylaniine.  It  fol- 
lows that  monochloracetone  has  the  constitution  C0Me'CH2Cl. 
The  action  of  a  warm  concentrated  solution  of  potash  on  dichlor- 
hydrin  yields  a  liquid  closely  resembling  monochloracetone  in  its  phy- ' 
sical  properties.  It  boils  at  118-119°  ;  sp.  gr.  at  11°  =  1-194.  It 
combines  with  hydrochloric  and  acetic  acids,  forming  derivatives  of 
glycerol,  and  it  also  combines  with  water.  With  alcoholic  ammonia, 
it  yields  the  badly  defined  compound  hemichlorhydramine,  CsH^gC'lNOa; 
this  is  evidently  not  an  acetone-derivative,  and  it  most  probably  has 
pTT 
the  constitution  CH2C1-CH  <_qJ>  . 
Dichlora'ietone  is  best  prepared  by  the  prolonged  action  of  chlorine 
on  well-cooled  acetone.  It  boils  at  120°,  whilst  the  monochloro- 
derivative  boils  at  117°,  but  the  two  compounds  may  be  separated  by 
taking  advantage  of  the  fact  observed  by  Mulder  and  by  Barbaglia, 
that  the  product  obtained  under  these  conditions  has  the  composition 
of  the  dichloracetone  even  in  the  fraction  boiling  at  170°.  The  frac- 
tion boiling  at  125-170°  is  collected  separately  and  purified  by  further 
fractionation.  The  pure  compound  boils  at  120°  ;  sp.  gr.  at  15°  = 
1*231.  It  combines  readily  with  sodium  hydrogen  sulphite,  and  the 
compound  crystallizes  with  3  mols.  HgO.  Even  when  carefully  puri- 
fied, the  vapor  acts  energetically  on  the  eyes,  etc.,  but  after  some  time 
the  organs  become  insensitive  to  its  action.  Ammonia  acts  rapidly  on 
dichloracetone,  with  formation  of  ammonium  chloride  and  the  base 
COMe'CHCl'NHg,  which  yields  methylamine  when  distilled  with 
potash. 
The  product  of  the  action  of  chlorine  on  cooled  acetone  has  the 
composition  of  the  dichloro-derivative  even  in  the  fraction  boiling  at 
170°,  but  on  redistillation  the  boiling  point  is  reduced  to  120°.  Bar- 
baglia  obtained  a  liquid  which  boiled  at  165 — 170°,  and  when  cooled 
solidified  to  a  mass  of  bulky,  prismatic  crystals  melting  at  44°.  In 
its  physical  properties,  this  product  resembles  symmetrical  dichlorace- 
tone, but  with  bromine  it  yields  a  dichlorodibromacetone  identical  with 
that  obtained  from  unsymmetrical  dichloracetone,  and  very  different 
from  the  corresponding  compound  obtained  from  the  symmetrical 
derivative.    This  high  boiling  fraction  may  be  a  polymeride. 
Symmetrical  dichloracetone  is  obtained  by  the  action  of  silver 
chloride  on  the  symmetrical  diiodoacetone  prepared  by  the  action  of 
iodine  chloride  on  acetone  in  presence  of  water.    It  has  a  pungent 
