PROPIONYL The radical assumed to exist in a number of organic compounds collectively known as the propienie group, and of which the chief member is propionic acid: The name is derived from rparros, first, and %law, fat, because propionic acid is the first in the series of fatty acids, which separates as an oily layer when liberated in aqueous solutions of its salts.
Hydride of propionyl H). Atetacetio or propionic aldehyde.— This is one of the products ofjthe oxidation of albumen, fibrin, or casein, by a mixture of sulphuric acid with either binoxide of manganese, or bichromate of potash. It is isolated from other matters that are obtained at the same time, by fractional distillation.
Hydride of prepionyl is a limpid liquid, of agreeable ethereal odour, sp. gr. 0'79 • boiling point between 130° and 150° Fahr., and vapour density 2•111. It slowly acidifies when exposed to the air.
Hydride of pentachloropropionyl H), or propionic chloral, is one of the products of the action of hydrochloric acid and binoxide of manganese upon starch. It is an oily liquid, crystallising in rhombic tables on exposing to a temperature of 32° Fahr.
Propione or the ethylide of propionyl (C„11,0„ The product of the destructive distillation of propionate of baryta. It
is a colourless or slightly yellow-coloured liquid of agreeable odour, insoluble in water, but soluble in alcohol or ether. Its boiling point is 212* Fshr. It is inflammable, burning with a pale blue flame. Nitric acid converts it into propionia acid.
;11,0, Propionic anhydride, or amAydrows propionic acid Is a colourless liquid formed on distilling a mixture of two of oxychlorkle of phosphorus, and six of dried propionate of soda. It has a disagreeable odour, is not soluble in water, and boils at 329" Fehr.
Propionie acid fro ). hictacetie acid, or metacetonie This acid is one of the products of the oxidation of oloio acid ; it Is also produced by the action of strong caustic potash upon sugar, starch, gum, or mannite, and by the action of ferments upon glycerin. The most convenient method of preparing it is to add cyanide of ethyl drop by drop to a concentrated alcoholic solution of potash contained In a retort. The reaction that then takes place is thus expressed :—