460 



scHiBABiN does not mention the dipj'ridyl amine. He prepared the 

 dipyridjiamine from «-eliloorpjridine and «-aminopjridine by heating 

 with zinc chloride, and gives as meltingpoint 86 — 87°. 



We have [)repared a picrate from the dipjridjlamine, which melts 

 at 227". 



Our observations on the melting-points of dipj'ridylamine itself, 

 on the salt with hydrochloric acid, and on the picrate of this base 

 are in perfect harmony with Stkinhauseh and Dikpoldkr's records, 

 so that we have no reason to doubt tlie identity of our preparation. 



The investigation of the components of the oil that goes over 

 at 130 — -180° and 15 m.m. pressure, was not yet completed then, 

 foi' a large part of this oil remained liquid after treatment with 

 hydrochloric acid. We removed the hydrochloric acid from this 

 liquid pai't, and then distilled the oil at ordinary pressure. We, col- 

 lected three fractions, viz. of 293—295°, of 295—300° and above 

 300^. The first two fractions had a nitrogen percentage of 13.9 "/oJ 

 the fraction above 300° had 16.47o ^^ nitrogen. From this last 

 fraction a little dipyridylamine was still deposited. The first two 

 fractions were joined ; this liquid appeared to be strongly unsaturated: 

 it immediately decolours a solution of permanganate and soda at 

 ordinary temperature. We have subjected part of this liquid to the 

 oxidation with sodium permanganate in sulphuric acid solution. A 

 white substance, which crystallized in white leaves and melted at 

 74°, could be isolated. The nitrogen percentage of it was 8.0 7o- 

 This shows that it cannot be a dipyridylamine or a dipyridyl. 



Besides these crystals, a viscid liquid was obtained from the oxi- 

 dation product. The investigation of these substances is being con- 

 tinued. 



Tt appears from all this that on action of sodium amide on pyri- 

 dine there are formed, besides aminopyridine, several other pyridine 

 derivates, among which the y-y-dipyridyl seems to preponderate 

 quantitatively. Tschitschibabin likewise observed by-products in the 

 reactionproduct which arises from sodium amide and pyridine. 

 After the «-aminopyridine had been distilled off, he states that an 

 oil went over which distilled at 120 — 180° and at 15—20 m.m., 

 and besides a fraction tiiat went over at 180 — 250° and 15 — 20 m.m. 



From the fraction of 120 — 180° crystals are deposited which, 

 after recrystallisation from benzene, melted at 158°. Tschitschibabin 

 supposed these crystals to be y-aminopyridine, but he could not 

 identify the substance for want of material. From the oil distilled 

 at 180 — 250° this investigator isolated the u-d' diaminopyridine ; 

 there were also other substances present, which he did not identify. 



