PHENACETIN  , C2H5O•CsH4,NHCOCH1 (

para-acetaminophenetol), a drug prepared by acetylating para-phenetidin, or by heating para-acetylaminophenol and potassium ethyl sulphate with alcoholic soda to 15o° C . Para-phenetidin is prepared by treating the sodium salt of para-nitrophenol with ethyl iodide, and reducing the nitrophenetol to para-phenetidin or aminophenetol . The yield may be doubled by diazotizing para-phenetidin, coupling with phenol, ethylating and reducing: EtO•CEHeNH2-->EtO•CsH4•N20H-->EtO•CsH4.N2.CEH•OH- EtO• C6144•N2•C6H4.OEt->2EtO•C6H4•NH2 . It crystallizes from water in colourless plates, melting at 135° C . It is. soluble in about 70 parts of hot and in about 1400 parts of cold water . Several compounds related to phenacetin have been introduced into medicine . Triphenin is propylphenetidin; lactophenin is lactylphenetidin; pyrantin is para-ethoxyphenyl succinimide, EtO•C6H4•N[CO•C112]2; salophen or saliphenin is salicylphenetidin; amygdophenin is mandelylphenetidin . In addition, several other derivatives have been suggested which have a greater solubility than phenacetin, e.g. phesin, which is the sodium salt of phenacetin sulphonic acid, apolysin and citrophen (citrophenin), which are citric acid derivatives of para-phenetidin, &c . Phenacetin is contained in both the British and United States pharmacopoeia, in the latter under the name of acetphenetidin . The dose is 5 to to grs. given in cachets or in suspension . When the drug is carelessly made it may contain impurities, producing considerable irritation of the kidneys . The physiological action of phenacetin consists in a sedative action on the sensory tracts of the spinal cord, and a depressant action on the heart, where it tends to paralyse the action of the cardiac muscle .

Upon the bodily

heat it exercises a marked effect, decreasing the action of the heat-producing centre as well as increasing the dissipation of heat, and thus causing a marked fall in temperature . In toxic doses the blood becomes dark and blackish from the formation of methaemoglobin, and the urine is changed in colour from the passage of altered blood . The chief therapeutic use of phenacetin is as an antineuralgic, and it is of service in migraine, rheumatism of the sub-acute type, intercostal neuralgia and locomotor ataxia .