252 JVillstätter's Researches on Chlorophyll [Jan. 



carboxyl group may be removed, however, by heating for a short 

 time with soda-lime in a test tiibe, small amounts of material being 

 used and the temperature conditions being carefully regulated. The 

 phyllines decompose easier and give cleaner reaction-products than 

 the porphyrines, so that the best method for preparing carboxyl- 

 free porphyrine is through the phylHne. 



Etiophylline^^ is obtained as f ollows : Potassium rhodophylHne 

 is rubbed with four or five parts of pure (iron-free) soda-Hme and 

 heated in lots of 0.05 to o.i gm. of the salt over a free flame until 

 the color changes from a hght gray to a brown, and the odor of 

 hemopyrrole becomes evident. At this point the heating is discon- 

 tinued and the tube qiiickly cooled. The contents are moistened 

 with a Httle water and shaken with ether. The ether sol. is shaken 

 with methyl alcoholic potash sol., the potash layer diluted with 

 water, the ether shaken with 5 percent hydrochloric acid, then with 

 ammonia, conc. to 2 c.c, and the prodnct recrystallized from i c.c. of 

 ether. The yield from 10 gm. of the salt is 0.4 gm. of pure sub- 

 stance. This yields nearly 8 percent of pure magnesium oxide, 

 when ashed. It has the composition indicated by the formula, 

 C3iH34N4Mg; forms thick rose or blue-violet tables or prisms from 

 ether, deep red rhombic tables from petroleum ether. The ether 

 sol. is Stahle towards 4 or 7 percent hydrochloric acid and is first 

 decomposed by 15 percent hydrochloric acid. In petroleum ether it 

 is decomposed by 0.5 percent acid, completely by 3 percent. The 

 alcoholic sol. is bluish red with strong fluorescence; diluted, it is 

 violet. 



Etioporphyrine is best prepared by shaking the ether sol. of the 

 phylline with 20 percent hydrochloric acid, neutralizing the product 

 with ammonia and extracting with ether, from which it may be 

 shaken out with 4 percent hydrochloric acid. It may also be pre- 

 pared by heating phyllo-, pyrro- or rhodoporphyrine with soda-lime, 

 until vapors are given off. Treated with methyl magnesium iodide, 

 it gives the phylline. It has the composition indicated by the form- 

 ula, C31H36N4; has a violet color, giving a brownish red alcoholic 

 sol. and a bluish red sol. in formic acid. It forms characteristic 

 complex Compounds with the salts of the heavy metals. The acetic 

 acid sol. warmed with zinc acetate gives a pure red sol., while cop- 



30 Willstätter and Fischer: Ann. d. Cheni., 400, 182 (1913). 



