ANTIPYRINE (phenyldimethyl pyrazolone) (C11H12N2O), is prepared by the condensation of phenylhydrazine with aceto-acetic ester, the resulting phenyl methyl pyrazolone being heated with methyl iodide and methyl alcohol to 100-110° C.:
CH3·C=N \ CH3·C-N·CH3 >N·C6H5 -> || >N·C6H5 CH2-CO / HC-CO Phenyl methyl pyrazolone Antipyrine
On the large scale phenylhydrazine is dissolved in dilute sulphuric acid, the solution warmed to about 40° C. and the aceto-acetic ester added. When the reaction is complete the acid is neutralized with soda, and the phenyl methyl pyrazolone extracted with ether and distilled _in vacuo_. The portion distilling at about 200° C. is then methylated by means of methyl alcohol and methyl iodide at 100-110° C., the excess of methyl alcohol removed and the product obtained decolorized by sulphuric acid. The residue is treated with a warm concentrated solution of soda, and the oil which separates is removed by shaking with benzene. The benzene layer on evaporation deposits the anti-pyrine as a colourless crystalline solid which melts at 113° C. and is soluble in water. It is basic in character, and gives a red coloration on the addition of ferric chloride. In medicine anti-pyrine ("phenazonum") has been used as an analgesic and antipyretic. The dose is 5-20 grs., but on account of its depressant action on the heart, and the toxic effects to which it occasionally gives rise, it is now but little used. It is more safely replaced by phenacetine.
ANTIQUARY, a person who devotes himself to the study of ancient learning and "antiques," i.e. ancient objects of art or science. The London Society of Antiquaries was formed in the 18th century to promote the study of antiquities. As early as 1572 a society had been founded by Bishop Matthew Parker, Sir Robert Cotton, William Camden and others for the preservation of national antiquities. This body existed till 1604, when it fell under suspicion of being political in its aims, and was abolished by James I. Papers read at their meetings are preserved in the Cottonian library and were printed by Thomas Hearne in 1720 under the title _A Collection of Curious Discourses_, a second edition appearing in 1771. In 1707 a number of English antiquaries began to hold regular meetings for the discussion of their hobby and in 1717 the Society of Antiquaries was formally reconstituted, finally receiving a charter from George II. in 1751. In 1780 George III. granted the society apartments in Somerset House, Strand. The society is governed by a council of twenty and a president who is _ex officio_ a trustee of the British Museum. The present headquarters of the society are at Burlington House, Piccadilly.