433 



Properties of ihe pijridyl-pyrrole melting at 132° 5. 



This substance, which as we already remarked, is not volatile 

 with water vapoui-, and is separated in this way from tiie isomer 

 melting at 90°, crystallizes from alcohol or benzene in leaves joined 

 to rosettes; from hot water long needles are obtained. 



This base is readily solnble in alcohol, ether, acetone, chloroform, 

 and benzene; not so easily in ligroine and hot water, very little soluble 

 in low-boiling petroleum ether. As far as the solubility |iropprties 

 are concerned, there is, therefore, a close agreement with the isomer 

 melting at 90°. The ethereal solution shows a blue fluorescence. 



We found 19,34°/, and 19,(52 ",, for the nitrogen content (calculated 

 for CjHgN, : 19,44 7, N). This base does not give a colour reaction 

 with a pine-chip moistened with hydrochloric acid; with a hydro- 

 chloric acid solution of dimethylamino-benzaldehyde there a|)pears, 

 however, a cherry-red colour, which has changed into blueviolet 

 after a day. 



That iliis sulistance, too, possesses a pyrrole nucleus, appears again 

 from the behaviour towards metallic potassium. The base was 

 dissolved in toluene and llie caUuilated tjiiantity of potassium was 

 added. The potassium dissolves with vigorous generation of hydrogen; 

 the reaction is much more rapid than with the isomer of melting- 

 point of 90°. The |)otassiiitii compouiul is deposited as a white powder. 



We have oxidized the pyridyl jiyrrole of melting-point 132.5 in 

 the same way with potassium permanganate in an acid solution, as 

 we already described for the isomer of melting-point of 90°. From 

 the pyridyl pyrrole melting at 132°. 5 we likewise obtained picolinic 

 acid, which melted at 136°. 8 after sublimation, and was identical 

 with the piculinic acid from picoline. 



It results from tlie.se experiments that the two substances that 

 aie formeti from N-(r(-pyridyl)-pyiTole, are two isomeric C-(<(-pyridyl)- 

 pyrroles, which are distinguished in this that the pyrrole-niu'leus in 

 one substance is substituted at the «-place, and in the other substance 

 at the (i-place, as is expressed in formulae (VI) and (VII). 



We may also mention that in this reaction chiefly the isomer 

 melting at 90° is foinied ; the quantity of the isomer melting at 

 132°.5 is small. 



§ 4. The metliijhition of the C-{(t-pyridi/l)-pyroIe of meltiny-poiiit dO°. 



The next step in the .synthesis of a substance isomeric with nicotine 

 ivS that the hydrogen atom of the imide group of the pyrrole-nucleus 

 is replaced by the methyl rest. 



