By passing the vapour of this compound through a red-hot tube, it yields the isomeric a0- pyridylpyrrol, the potassium salt of which with methyl iodide gives a substance methylated both in the pyridine and pyrrol nuclei.
The three primary members are furfurane, thiophene and pyrrol, each of which contains four methine or CH groups, and an oxygen, sulphur and imido (NH) member respectively; a series of compounds containing selenium is also known.
Pyrrol yields an analogous series: pyrazole, imidazole or glyoxaline, azimide or osotriazole, triazole and tetrazole: CH=N N=CH N=N CH=CH' CH =CH' CH =CH' Pyrazole.
One or two benzene nuclei may suffer condensation with the furfurane, thiophene and pyrrol rings, the common carbon atoms being vicinal to the hetero-atom.
PYRROL, C 4 H 5 N or C 4 H 4 NH, an organic base found in coaltar and Dippel's oil.
The pyrrol ring is easily broken, e.g.
Pyrrol is readily converted into pyridine derivatives by acting with bromoform, chloroform, or methylene iodide on its potassium salt, t3-brom-and O-chlorpyridine being obtained with the first two compounds, and pyridine itself with the last.
Iodine in alkaline solution converts pyrrol into iodol (tetra-iodopyrrol), crystallizing in yellowishbrown needles, which decompose on heating.
Zinc dust and hydrochloric acid reduce pyrrol to pyrrolin (dihydropyrrol), C 4 H 6 NH, a liquid which boils at 90° C. (748 mm.); it is soluble in water and has strongly basic properties and an alkaline reaction.
Hydriodic acid at high temperature reduces pyrrol to pyrrolidine (tetra-hydropyrrol), C 4 H 8 NH.
Reduction of this ester leads to the formation of ammonia, hydroxylamine, and dimethyl pyrrol dicarboxylic ester, C(CH3): C C02R HN< C(CO 2 R) :C CH3.
He also found that diaceto succinic ester reacts with compounds of the type NH 2 R(R = H, CH 3, OH, NHC 6 H 5, &c.) to form pyrrol derivatives CH3 CO CH CO 2 R, C(CH3) :C C02R A NH 2 R -?- - RN(CH 3 CO CH CO 2 R C(CH3) :C C02R By using compounds of the type NH 2 R and acetophenone acetoacetic ester C 6 H 5 CO CH 2.
Paal has also obtained pyrrol derivatives by condensing acetophenone-acetoacetic-ester with substances of the type NH2R.
By a dilute acid haemoglobin is decomposed into globin, and " haematin," a ferri-pyrrol derivative of the probable formula C34H34N4FeOs; under certain conditions the iron-free " haematoporphyrin " is obtained.
This last substance may be reduced to mesoporphyrin, C34H3804N4, which by further reduction gives haemopyrrol, C 8 11 13 N, possibly methyl-propyl-pyrrol or butyl-pyrrol.
The -y-diketones are characterized by the readiness with which they yield furfurane, pyrrol and thiophene derivatives, the furfurane derivatives being formed by heating the ketones with a dehydrating agent, the thiophenes, by heating with phosphorus pentasulphide, and the pyrrols by the action of alcoholic ammonia or amines.
The ammonium salt yields on dry distillation carbon dioxide, ammonia, pyrrol and other substances.
Moissan, contains only a trifling amount of morphia, and the effect produced by it is apparently due, not to that alkaloid, but to such decomposition products as pyrrol, acetone and pyridine and hydropyridine bases.
Formulae have been proposed by Pschorr and Knorr explaining this and other decompositions (in Pschorr's formula the morphine ring system is a fusion of a phenanthrene and pyridine nucleus); another formula, containing a fusion of a phenanthrene with a pyrrol ring, was proposed by Bucherer in'1907.
To celebrate his seventieth birthday his scientific papers were collected and published in two volumes (Gesammelte Werke, Brunswick, 1905), and the names of the headings under which they are grouped give some idea of the range and extent of his chemical work: (1) organic arsenic compounds, (2) uric acid group, (3) indigo, (4) papers arising from indigo researches, (5) pyrrol and pyridine bases, (6) experiments on the elimination of water and on condensation, (7) the phthaleins, (8) the hydro-aromatic compounds, (9) the terpenes, (io) nitroso compounds, (11) furfurol, (12) acetylene compounds and "strain" (Spannungs) theory, (13) peroxides, (14) basic properties of oxygen, (15) dibenzalacetone and triphenylamine, (16) various researches on the aromatic and (17) the aliphatic series.
Ramsay, Ber., 1877, 10, p. 736); by heating pyrrol with sodium methylate and methylene iodide to 200° C. (M.