PYRIDINE  , C51-15N, an organic See also:

• BASE

base, discovered by T . See also:

• ANDERSON
• ANDERSON, ADAM (1692—1765)
• ANDERSON, ALEXANDER (c. 1582-1620?)
• ANDERSON, ELIZABETH GARRETT (1836— )
• ANDERSON, JAMES (1662—1728)
• ANDERSON, JAMES (1739-1808)
• ANDERSON, JOHN (1726-1796)
• ANDERSON, MARY (1859– )
• ANDERSON, RICHARD HENRY (1821–1879)
• ANDERSON, ROBERT (1750–1830)
• ANDERSON, SIR EDMUND (1530-1605)

Anderson (Trans . See also:

• ROY, WILLIAM (1726-1790)

Roy . See also:

• SOC

Soc . Edin., 1851, 20, p . 251) in See also:

• BONE (a word common in various forms to Teutonic languages, in many of which it is confined to the shank of the leg, as in the German Bein)
• BONE, HENRY (1755-1834)

bone oil . It is also found among the See also:

• DISTILLATION (from the Lat. distillare, more correctly destillare, to drop or trickle down)

distillation products of bituminous See also:

• COAL

coal, See also:

• LIGNITE (Lat. lignum, wood)

lignite, and various shales, and has been detected in fusel oil and crude See also:

• PETROLEUM (Lat. Petra, rock, and oleuin, oil)

petroleum . It is a decomposition product of various alkaloids (See also:

• NICOTINE, C10H

nicotine, sparteine, cinchonine, &c.), being formed when they are strongly heated either alone or with See also:

• ZINC

zinc dust . It may be synthetically prepared by distilling allyl ethylamine over heated See also:

• LEAD
• LEAD (pronounced iced)

lead See also:

• OXIDE

oxide (W . Konigs, Ber., 1879, 12, p . 2341) by passing a mixture of See also:

• ACETYLENE

acetylene and hydrocyanic See also:

• ACID (from the Lat. root ac-, sharp; acere, to be sour)

acid through a red-hot See also:

• TUBE (Lat. tuba)

tube (W . See also:

• RAMSAY, ALLAN (1686-1758)
• RAMSAY, ALLAN (1713-1784)
• RAMSAY, ANDREW MICHAEL (1686-1743)
• RAMSAY, DAVID (1749—1815)
• RAMSAY, SIR WILLIAM (1852– )
• RAMSAY, SIR WILLIAM MITCHELL (185r– )

Ramsay, Ber., 1877, 10, p .

736); by See also:

• HEATING

heating See also:

• PYRROL, C4H5N

pyrrol with See also:

• SODIUM [symbol Na, from Lat. natrium; atomic weight 23.00 (0=16)]

sodium methylate and methylene iodide to 2o0° C . (M . Dennstedt and J . See also:

• ZIMMERMANN, JOHANN GEORG, RITTER VON

Zimmermann, Ber., 1885, 18, p . 3316); by heating isoamyl nitrate with See also:

• PHOSPHORUS (Gr. 4ws, light, sPEpety, to bear)

phosphorus pentoxide (E . T . See also:

• CHAPMAN (from O. Eng. ceap, and Mid. Eng. ,heap, to barter, cf. " Cheapside " in London, and Ger. Kaufmann)
• CHAPMAN, GEORGE (? 1559–1634)

Chapman and M . H . See also:

• SMITH
• SMITH, ADAM (1723–1790)
• SMITH, ALEXANDER (183o-1867)
• SMITH, ANDREW JACKSON (1815-1897)
• SMITH, CHARLES EMORY (1842–1908)
• SMITH, CHARLES FERGUSON (1807–1862)
• SMITH, CHARLOTTE (1749-1806)
• SMITH, COLVIN (1795—1875)
• SMITH, EDMUND KIRBY (1824-1893)
• SMITH, G
• SMITH, GEORGE (1789-1846)
• SMITH, GEORGE (184o-1876)
• SMITH, GEORGE ADAM (1856- )
• SMITH, GERRIT (1797–1874)
• SMITH, GOLDWIN (1823-191o)
• SMITH, HENRY BOYNTON (1815-1877)
• SMITH, HENRY JOHN STEPHEN (1826-1883)
• SMITH, HENRY PRESERVED (1847– )
• SMITH, JAMES (1775–1839)
• SMITH, JOHN (1579-1631)
• SMITH, JOHN RAPHAEL (1752–1812)
• SMITH, JOSEPH, JR
• SMITH, MORGAN LEWIS (1822–1874)
• SMITH, RICHARD BAIRD (1818-1861)
• SMITH, ROBERT (1689-1768)
• SMITH, SIR HENRY GEORGE WAKELYN
• SMITH, SIR THOMAS (1513-1577)
• SMITH, SIR WILLIAM (1813-1893)
• SMITH, SIR WILLIAM SIDNEY (1764-1840)
• SMITH, SYDNEY (1771-1845)
• SMITH, THOMAS SOUTHWOOD (1788-1861)
• SMITH, WILLIAM (1769-1839)
• SMITH, WILLIAM (c. 1730-1819)
• SMITH, WILLIAM (fl. 1596)
• SMITH, WILLIAM FARRAR (1824—1903)
• SMITH, WILLIAM HENRY (1808—1872)
• SMITH, WILLIAM HENRY (1825—1891)
• SMITH, WILLIAM ROBERTSON (1846-'894)

Smith, See also:

• ANN

Ann., 1868, Sup p1 . 6, p . 329); and by heating piperidine in acetic acid See also:

• SOLUTION (from Lat. solvere, to loosen, dissolve)

solution with See also:

• SILVER

silver acetate (J . Tafel, Ber., 1892, 25, p .

1619) . The amount of pyridine produced in most of these processes is very small, and the best source for its preparation is the " See also:

• LIGHT

light-oil " fraction of the coal-See also:

• TAR

tar distillate . The basic constituents are removed by dilute sulphuric acid, the acid layer removed, and the bases liberated by See also:

• ALKALI

alkali, separated, dried, and fractionally distilled . Pyridine is a colourless liquid of a distinctly unpleasant, penetrating odour . It boils at 114.5° C., and is miscible with See also:

• WATER

water in all proportions . It is a See also:

• TERTIARY

tertiary base, and combines readily with the alkyl halides to See also:

• FORM (Lat. forma)

form pyridinium salts . Nascent See also:

• HYDROGEN [symbol H, atomic weight x-oo8 (0=16)]

hydrogen reduces it to piperidine, C5H11N (see below), whilst hydriodic acid above 300° C. reduces it to n-pentane (A . W . See also:

• HOFMANN, AUGUST WILHELM VON (1818-1892)
• HOFMANN, JOHANN CHRISTIAN KONRAD VON (1810—1877)
• HOFMANN, MELCHIOR (c. 1498—1543-4)

Hofmann, Ber., 1883, 16, p . 59o) . •It is a very See also:

• STABLE

stable See also:

• COMPOUND
• COMPOUND (from Lat. componere, to combine or put together)

compound, chromic and nitric acids being without See also:

• ACTION

action upon it, whilst the See also:

• HALOGENS

halogens only yield substitution derivatives with difficulty . It reacts with sulphuric acid only at high temperatures, yielding a sulphonic acid .

It forms addition compounds with mercuric and auric chlorides . On the constitution of the pyridine See also:

• NUCLEUS (Lat. for the kernal of a nut, nux, the stone of fruit)

nucleus, see Korner, Gior. dell' acad. di See also:

• PALERMO (Greek, Havopuos; Latin, Panhormus, Panormus)

Palermo, 1869, and C . Riedel, Ber., 1883, 16, p . 1609 . As regards the See also:

• ISOMERISM

isomerism of the pyridine substitution products, three mono-derivatives are known, the different positions being indicated by the See also:

• GREEK
• GREEK, ETRUSCAN AND

Greek letters a, /3 and y, as shown in the inset See also:

• FORMULA
• FORMULA (Lat. diminutive of forma, shape, pattern, &c., especially used of rules of judicial procedure)

formula . This 4 e formula also allows of the existence of six di-deriva- tives, six tri-derivatives, three tetra- and one penta- derivative, when the substituent See also:

• GROUPS
• GROUPS, THEORY

groups are identi-°` \N%a cal; all of which are in agreement with known facts . The three monochlorpyridines are known, the a and y compounds resulting from the action of phosphorus pentachloride on the corresponding oxypyridines, and the fl compound from the action of See also:

• CHLOROFORM (trichlor-methane), CHC13

chloroform on See also:

• POTASSIUM [symbol K (from kalium), atomic weight 39.114 0=16)]

potassium pyrrol. a-Aminopyridine, C5H4N•See also:

• NH2

NH2, is formed by heating 5-aminopyridine-2-carboxylic acid . It is a crystalline solid which melts at 56° C. and boils at 204° C . It can only be diazotized in the presence of concentrated sulphuric acid, and even then the See also:

• FREE

free diazonium sulphate is not stable, readily passing in the presence of water to a-oxypyridine . $-Aminopyridine is obtained by heating $-pyridyl See also:

• URETHANE, NH2CO

urethane with fuming hydrochloric acid until no more See also:

• CARBON (symbol C, atomic weight 12)

carbon dioxide is liberated (T . See also:

• CURTIUS, ERNST (1814-1896)
• CURTIUS, MARCUS

Curtius and E . See also:

• MOHR, KARL FRIEDRICH (1806-1879)

Mohr, Ber., 1898, 31, p .

2493), or by the action of See also:

• BROMINE (symbol Br, atomic weight 79-96)

bromine and See also:

• CAUSTIC (Gr. rcavvraubs, burning)

caustic soda on the See also:

• AMIDE

amide of nicotinic acid (F . Pollak, Monats., 1895, 16, p . 54) . It melts at 64° C. and boils at 250-252° C . The aminopyridines are readily soluble in water, and resemble the aliphatic See also:

• AMINES

amines in their See also:

• GENERAL
• GENERAL (Lat. generalis, of or relating to a genus, kind or class)

general chemical properties . The oxypyridines may be prepared by distilling the corresponding oxypyridine carboxylic acids with See also:

• LIME
• LIME (O. Eng. lim, Lat. limes, mud, from linere, to smear)

lime, or by fusing the pyridine carboxylic acids with caustic potash . The mono-oxypyridines are easily soluble in water and possess only feeble basic properties . The compound is hydroxylic in See also:

• CHARACTER (Gr. xapareri7p, from xap&crew, to scratch)

character, whilst the a and y derivatives behave frequently as if they possess the tautomeric ketostructure, yielding according to the conditions of the experiment either N- or 0-See also:

• ETHERS

ethers (H. v . Pechmann, Ber., 1895, 28, p._1624), thus corresponding to the formulae CH CH C.OH CO HC/\CH HC" CH HC/\CH HC CH HC\ jC•OH HC\/CO HC'\ CH HC/I CH N NH N~ NH a-oxypyridine a-pyridone y-oxypyridine 7-pyridone The homologues of pyridine may be synthesized in various ways . One of the most important is the so-called " collidine " See also:

• SYNTHESIS (Gr. a6vOeacs, from avvrcBivac, to put together)

synthesis of A . Hantzsch (Ann., 1882, 215, p . I ; Ber., 1882, 15, p .