Interaction of ketones and aldehydes with acid chlorides : the formation of benzoxy-olefines and 1-benzoxy-camphene / by Frederic H. Lees.

Lees, F. H. (Frederic Herbert)

Date:: [1903]

Credit: Interaction of ketones and aldehydes with acid chlorides : the formation of benzoxy-olefines and 1-benzoxy-camphene / by Frederic H. Lees. Source: Wellcome Collection.

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$identified by its melting point, 115—116°, and its specific rotation, [a]D -42-1°. Action of Bromine.—1-Benzoxycamphene, when subjected to the action of bromine in the manner indicated under /3-benzoxyundecylene, afforded a heavy, yellow oil, which, when distilled under 30 mm. pressure, yielded two fractions, one distilling below 150° and the other at 150—170°. The first fraction, when redistilled under the ordinary pres¬ sure, boiled at 220—230° and was identified as benzoyl bromide. The higher fraction, which solidified after some hours, was drained on a porous tile and recrystallised several times from light petroleum; it separated in needles melting at 75—76°, and was identified as a bromocamphor. This compound was also produced when 1-benzoxycamphene (2 grams), dissolved in cold glacial acetic acid (50 c.c.) containing several grams of anhydrous potassium acetate in solution, was slowly treated with bromine, added drop by drop, until present in slight excess. The product, when poured into water containing sulphurous acid, yielded a heavy oil, which subsequently crystallised on shaking with warm dilute sodium carbonate solution. This substance, when re¬ crystallised from methyl alcohol, melted sharply at 75—76° and did not depress the melting point of a-bromocamphor. That it was a-bromocamphor was further shown by a determination of its specific rotation in ethyl alcohol, which proved to be [a]D + 131°. a-Benzoxy-a-heptylene, C5H11 • CH !CH • O • CO• C6H5. This was prepared from w-heptaldehyde and benzoyl chloride. In this operation, large quantities of benzoic acid are produced, and on this account the product is conveniently purified by agitation with sodium carbonate solution in the presence of ether. The dried ethereal extract yielded two fractions, one boiling at 190—200° and the other at 205—275°, under 50 mm. pressure. The lower fraction, on redistillation, passed over almost entirely at 195° under 50 mm. pressure. On analysis : I 0-1162 gave 0-3262 C02 and 0*0900 H20. C = 76-6; H = 8*6. 9 C14H1802 requires 0 = 77*1 ; H = 8*3 per cent. This fraction, which consists therefore of a-benzoxy-a-heptylene, ■j resembles in all respects the benzoxy-derivatives prepared from the ketones. The yield amounted to 50 per cent, of the aldehyde t employed. The higher fraction, which distilled at 205—275° under 50 mm. n pressure, doubtless consisted of condensation products of n-hept- II aldehyde (compare Perkin, Trans., 1883, 43, 45). The formation of ll a large amount of benzoic acid, which occurs in the preparation of$