A volatile oil has been prepared by Spalteholz1), of Haarlem, from the hyacinth (Hyacinthus orientalis, L., family Liliaceae). Immediately after picking, the flowers were transferred to zinc containers and brought into contact for a few minutes with benzene, which had been purified by freezing. The benzene was drawn off and the flowers washed a second time with the solvent, 381 kg. of flowers being treated in this way with 200 /. of benzene. Under diminished pressure the solution was concentrated to 2 /. at a temperature of 30°. The fats and waxes were then precipitated with dilute alcohol, the solution filtered and concentrated still further in vacuo. The resulting oil (60,5 g. = 0,016 p.c.) as such, had a disagreeable and pungent odor and only after considerable dilution did it develop the natural hyacinth odor.
Spalteholz identified hydrogen sulphide in the aqueous solution of potassium hydroxide with which the oil had been shaken. 10 g. of this oil were turned over to Enklaar for a chemical examination for which he used 7,7 g. He first removed fatty oil and resin from the crude product by exposing the petroleum ether solution thereof to - 20°. Thus he obtained 3,6 g. of a pure oil which, upon distillation under 10 mm. pressure, was resolved into three fractions: I. b.p. up to 90° 0,6 g.; II. 92 to 94° 1,3 g.; III. 94 to 150° 1,7 g.
Fraction I contained a very volatile substance with an unpleasant odor, that was not farther investigated. In fraction II Enklaar found a hitherto unknown substance which consisted of carbon, hydrogen and oxygen, and which revealed the following constants: b. p. 205 to 206° (760 mm.), 92 to 94° (10 mm.); d16o 0,907; aD + l°52'; nD16o1,4914. Fraction III contained benzyl benzoate and probably benzyl alcohol, also cinnamic alcohol as ester. The benzoic acid, regenerated from the alkaline saponification liquor, possessed a distinct odor of vanillin. In addition, this fraction contained a nitrogen-free basic substance which fluoresced, had a narcotic odor and was colored red by acids and yellow by alkalies. As to its properties it reminded one of oxonium compounds. The presence of anthranilic acid methyl ester and methylanthranilic acid ester could not be proved; for, when heating with trinitrobenzene, which forms difficultly soluble addition products with these substances, only a reddish coloration resulted.
1) C. J. Enklaar, Chem. Weekblad 7 (1910), 1.
The hyacinth wax crystallizes from alcohol in colorless laminae which persistently retain the odor of the flowers.