58 KANSAS Academy of Science. 



PAPERS. 



IODOFORM. 



Preparation from Acetone and Hypochlorites ; also, a Trial by Electricity. 



BY S. E. BOYOE, LAWBENCE. 



As everyone knows, the expensive part of iodoform is the iodine used in its 

 manufacture, and as this constitutes by weight 96.69 per cent, of the finished prod- 

 uct, it will readily be seen that its production must always be associated with ex- 

 pense. In working on a new formula for its production, the difficulty we aim to 

 overcome is the appropriation of iodine to form iodides which are lost in or have 

 to be recovered from the mother liquor. 



The best yields I have been able to find on record from any of the old methods 

 were recorded by Hager, who used Filhol's process and claimed 72 per cent, of the 

 iodine appropriated ; but Wilder, following the same directions, was able to obtain 

 only 42 to 58 per cent. (Proc. Am. Phar. Ass. 1875, 717.) 



We are now prepared to formulate a method by which practically all the iodine 

 used is converted into iodoform and the reaction is completed at once without the 

 labor and inconvenience of decomposing the mother liquor with nitric acid, as in 

 Filhol's process. 



The reaction is accomplished by the action of an alkaline solution of hypochlo- 

 rite on potassium iodide in presence of acetone. The chlorine and iodine exchange 

 positions, forming chloride and hypo-iodite. The iodine of the hypo-iodite imme- 

 diately unites with a portion of the methyl in the acetone, and the solution becomes 

 turbid from the abundant precipitation of iodoform. The greater part of the 

 acetone appears to be appropriated to the formation of acetates and carbonates of 

 the alkalies present. The following equation would probably approximate the reac- 

 tion : 3 KI + 3 KClO-f C3H60=CHl3+3 KCl+KC2H30, + 2 KOH. 



The operation requires no heat, and the precipitation is best conducted in a tall 

 cylindrical vessel, allowing the solution of hypochlorite to fall into the other solu- 

 tion drop by drop as long as a precipitate is formed. The vessel should be large, as 

 it requires about three parts of the former solution to one of the latter. As it is 

 difficult to decant the hypo, solution perfectly clear, I prefer to place a filter over 

 the receiver and turn on a small amount at a time, allowing it to drop as it comes 

 through the filter. The constant dropping keeps the solution in motion; and in 

 addition to this the receiver should be given an occasional rotary motion to facili- 

 tate the agglomeration and precipitation of the very minute crystals formed. 



A complete precipitation can be accomplished in an hour; and if any considera- 

 ble length of time is occupied, the solution should be protected from the light by 

 wrapping a piece of paper around the container, or by other simple device. 



The solutions are made as follows,* and special attention should be given to the 

 amount of acetone used, since experiments proved that smaller amounts would give 



proportionately smaller results : 



Solution No. l. 



Potassium iodide giu. 50 



Caustic soda gin. S 



Acetone giu. 40 



Dissolve the KI and the NaOH in one litre of water, and add the acetone. 



* Modification of a formula given by Sulliott and Raynand, Chem. Zeil., Jan. 16, 1889. Also, Bull. 

 Soc. Chem. 1889, 1,3. 



