34  Chlor  acetones.  {'^"'■/aT'iS^'"'' 
tinct  from  either  of  the  compounds  CO(CHCl2)2  and  CCls-CO'CHCl. 
Since  only  two  tetrachloracetones  can  exist,  it  follows  that  the  deri- 
vative from  dichlorhydrin  is  not  an  acetone-derivative.  Again,  when 
dichloracetone  and  the  pseud odichloracet one  are  subjected  to  the  action 
of  chlorine  in  sunlight,  the  products  are  very  different,  although  both 
have  the  composition  of  pentachloracetone.  Only  one  pentachlorace- 
tone  is,  however,  possible.  The  pseud odichtoracetone  is  a  derivative 
of  dichlorhydrin,  CH2C1'CH(0H)-CH2C1,  and  has  the  constitution 
CH2C1*CH  '<^^^^]^>  ,  analogous  to  that  of  epichlorhydrin.  Pseu- 
dodichlorhydrin  does  not  combine  with  acetic  acid.  It  reacts  violentlv 
with  concentrated  hydrochloric  acid,  but  when  the  product  is  evapo- 
rated over  sulphuric  acid  the  original  compound  is  obtained. 
Trichlor acetones, — When  a  limited  quantity  of  bromine  is  allowed 
to  act  on  dichloracetone,  the  product  CHCl2*CO'CH2Br  is  obtained, 
which  boils  at  111°  under  a  pressure  of  25  mm.,  and  when  this  is 
heated  with  mercuric  chloride  in  presence  of  alcohol,  trichloracetone 
boiling  at  172°  is  obtained.  This  trichloracetone  yields  no  chloro- 
form with  aqueous  or  alcoholic  ammonia,  and  no  phenylcarbylamine 
with  aniline  and  j^otash.  It  therefore  does  not  contain  the  group 
CCI3,  and  must  have  the  constitution  CHCIo'CO'CHoCl.  Only  a  very 
small  quantity  w^as  obtained. 
Trichloracetone,  CClg'CO  CH3,  is  readily  obtained  by  the  action  of 
chlorine  on  an  aqueous  solution  of  sodium  citraconate  heated  at  100° 
(Gottlieb  and  Morawsky,  t/.  j9r.  Chem.  [2],  xii,  369).  With  ammonia, 
it  yields  chloroform  and  a  small  quantity  of  ammonium  chloride,  to- 
gether with  a  large  quantity  of  acetamide  if  the  liquid  has  been  kept 
cool  and  excess  of  ammonia  has  been  avoided. 
The  action  of  chlorine  on  impure  methyl  alcohol  (Bonis)  or  on 
acetone  (Bischoff)  yields  a  liquid  which  has  the  composition  of  tri- 
chloracetone and  boils  at  172°;  sp.  gr.  1-418.  It  solidifies  incompletely 
in  long  needles  at  — 14°,  the  temperature  rising  suddenly  to  — 5°. 
The  crystals  melt  between  — 5°  and  -{-2°.  It  combines  with  2  mols. 
HoO,  forming  a  hydrate  which  melts  at  43 — 14°.  It  also  combines 
with  sodium  hydrogen  sulphite,  but  the  product  crystallizes  with 
great  difficulty.  With  aniline  and  potash,  it  yields  phenylcarbyl- 
amine; but  with  ammonia  it  yields  very  little,  if  any,  chloroform  or 
acetamide,  ammonium  chloride,  however,  is  formed  in  large  quantities, 
and  if  the  liquid  is  distilled  with  potash,  it  yields  dichloromethyla- 
