US554938A - Leonhard lederer - Google Patents

Description

operations being necessary, such as the break- UNITED STATES I PATENT OFFICE.

LEONIIABD LEDERER, OF MUNICH, GERMANY.

PROCESS OF OBTAINING PHENOLS.

SPECIFICATION forming part of Letters Patent No. 554,938, dated February 18, 1896.

Application filed October 9,

189 1. Serial No. 525,408. (No specimens.) laten'ted inGei-many April 3, 1894, No. 79,514; in

France September 13941 l,670; in Belgium September 26, 1894,110. 112,013; in England September 26, 1894, No. 18,272; in Italy September 30,1894, XXIX, 37,308, and LXXII'I, 120; in Austria. October 29, 1894, N0- Pi 5,710,

and in Hungary March 12, 1895,110. 2,381.

To all whom it 177 661] concern:

Be it known that I, LEONHARD LEDERER, doctor of philosophy, a subject of the King of Bavaria, residing at Munich, in the Kingdom of Bavaria, German Empire, have invented new and useful Improvements in Processes of Obtaining Pure Phenols from Mixtures, (for which I have obtained patents in Germany, No. 79,511, dated April- 3, 1894; in Austria, No. sit/5,710, dated October 29, 1891; in l-Iungary, No. 2,381, dated March 12, 1895; n France, No. 211,670, dated" September :0, 1891; in Belgium, No. 112,013, da d September 2b, 189-1; in Italy, Reg. Gen, ol. XXIX, No. 37,308, Reg. Att.,,Vol. LXXIII, No. 120, dated September 30, 1891, and in England, No. 18,27 2, dated September 26, 1894,) of which the following is a specification.

In order to obtain phenols in a pure state that is to say, free fromisomers and .homologues-it has hitherto been necessary to start from suit-able aromatic amido compounds, which were diazotized. In order to obtain favorable results the primary materials had to be in the purest possible condition and the diazo compounds had to be decomposed by steam. Although this method is generally applicable, yet it is almost without value for industrial purposes, because the process from the raw material (hydrocarbon) to the final product (phenol) is much too complex, many ing up of the hydrocarbons, nitration and separation of the isomeric nitro compounds, reduction and diazotation. For this reason it has often been attempted to'utilize for the manufacture of phenols the inexpensive crude phenols as they are obtained-for ex ample, as by-products in the manufacture of carbolic acid, and generally in the distillationof tar, or as they occur in vegetable oils. This, however, has not been practically successful, because the most careful and frequently-repeated fractioning of the free phenols or their ethers does not attain the desired result.

I have found that-the result is attained by converting the phenols, by means of chloracctic acid, into phenoxacetic acids, such as presence of sodaye.

phenoxyacetic acids or glycolphenylether acids. The phenoxacetic acids, the most simple of Which-viz., was produced several years ago by Heintz,

(Fahrcsbcricht 'itbevtdie Fortschriiiedc'r Che mic, 1859, p. 361,) are more or lessknown. After I had ascertained that the phenoxacetic acids are readily decomposed at a high temperature by mineral acids, and can be sep arated in a simple manner in the form of their sodium salts or as free acids, I undertook successfully the problem of effecting condensation between chloracetic acid and phenols in such a manner as to coincide as closely as possible with the theory. This, according to the literature on the subject hitherto accessible (Giacosa,'JowrnaZ fit?" Prakt'ische Ohemie, N. F. 19, 396; Fritzsche in the same, 20, 269) has only been effected either incompletely or at the sacrifice of the purity of the products, accompanied by difficulty of operating in a practical manner.

I heat to 100 to 120 centigrade for several hours the phenols with chloracetic acid in the The sodium phenoxacetates thus produced are separated either as the s alt-s, or after decomposing them by acids, in the form of the free 'phenoxacetic acids. Thus it is possible to effect with accuracy and certainty the. separation of the phenols, employing readily obtainable primary materials and simple steps of operations, and thus to fulfill all the conditions necessary for practical manufacture.

' Process I.-Ten parts crude cresol, nine parts chloracetic acid and thirty-three parts soda-lye, at twenty-five per cent strength, are heated to 100 to 120 centigradc for about twelve hours. The mixture sets when cold in a thick'semifiuid crystalline mass, from which there is separated by pressure a lye consisting of sodium orthocresox-acetate mixed with an equal quantity of uncombined cresols. These can be readily separated by washing out with ether or by blowing steam through the mixture. The crystalline cake formed by pressure is lixiviated with warm water, whereby sodium metacresox-acetate is dissolved while sodium paracrcsox-acetate remains behind the phenoxacetic acidscribed, of the tit-ies of mixed and is freed by recrystallizing from boiling Water, from the last traces of the metacresoxacetate salt. After removal, as above deuncombined cresols, the reaction product can be decomposed directly by hydrochloric acid or dilute sulfuric acid. The crude cresoxacetic acids are then first heated with ,a little warm benzene whereby the meta compound is dissolved. By means of boiling benzene (about four times the volume of the solid matter) the para acid is taken up,while the orthocresox-acetic acid remains behind owing to its being less soluble. In the same manner may be decomposed mixtures of other phenols, such as creosote, or oil of cloves.

Process II One part paracresoxacetic acid and eight parts hydrochloric acid are heated to 200 to 210 Centigrade for two hours. The

paracresol liberated is then freed by distillation in a current of steam from small quansubstances. The decompositionof the homologous phenoxacetic acids is eifected in like manner.

* I claim- I 1. The herein-described process for obtaining pure phenols from substances containing them, such as crude cresols, xylenols, thymol,

carvakrol, eugenol, guajakol and creosol, which consists in subjecting the said substances to the action of chloracetic acid in the presence of alkaline lye, then treating the alkaline salts thus produced with suitable mineral acids to produce therefrom separate phenoxacetic acids, and treating said phcnoxacetic acids with mineral acids to produce phenols, substantially as described.

2. The herein-described process of producing phenoxacetic acids, from substances containing phenols, which consists in treating said substances with chloracetic acid in the presence of soda-lye, to produce sodium phenoxacetates, then treating said sodium salts with diluted mineral acids to produce a mixture of phenoxacetic acids, and separating the several phenoxacetic acids by fractional solution or crystallization, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

LEONIIARD LEDERER.

Witnesses 4 LEONHARD WARKER, GEORG Conn.