UNITED STATES PATENT OFFICE. ALBRECHT SCHMIDT, OF BERLIN, GERMANY. PROTOCATECHUC ALDEHYDE-META-ALKYL-ETHERS AND PROCESS OF MAKING SAME,

SPECIFICATION forming part of Letters Patent No. 545,099, dated August 27, 1895. Application filed July 21, 1894, Serial No. 518,241 (No specimens.) To all, whom it may concern: aldehyde, then one molecular proportion of a Be it known that I, ALBRECHT SCHMIDT, a compound of the type of benzyl chlorid and 55 subject of the King of Prussia, residing at the whole warmed several hours on the Water Berlin, Prussia, Germany, have invented cer bath. The ether is isolated in the usual way, tain new and useful Improvements in and Re separated from any di-ether that is formed at lating to the Production of Protocatechuic the same time by dissolving in alkali liquor, Aldehyde-Meta-Alkyl-Ethers to be employed and then purified either by crystallization or, in perfuming and other uses; and I do here preferably, by conversion into the sodium or by declare the following to be a full, clear, and potassium salts, which are not very soluble in O exact description of the invention, such as aqueous alkali solutions. will enable others skilled in the art to which In the second operation the alkylation can it appertains to make and use the same. best be effected in the following manner: The The method relates to the production of alkali salts of the compounds of the type of protocatechuic-aldehyde-meta-alkyl-ethers, para -benzyl - protocatechuic - aldehyde are and the main principle of my invention con treated in alcoholic solution with an alkyl sists in substituting for the hydrogen of the haloid. In place of the alkyl haloid a salt of hydroxyl group being in para position to the alkylsulfuric acid can also be employed. COH group of protocatechuic- aldehyde, a In the third operation the aromatic ethers group that easily may be removed again-for so obtained are decomposed in a well-known instance, the benzyl group-i.e., at first in Way. obtaining compounds of the type of para In carrying out my invention I proceed as benzyl-protocatechuic-aldehyde. follows: 75 The method consists in the combination of the following three processes: first, convert I. Production of compounds of the type of 25 ing the mono-metallic salts of protocatechuic para-benzyl-protocatechuic-aldehyde. aldehyde into compounds of the type of para For example, para-benzyl-protocatechuic benzyl-protocatechuic-aldehyde; second sub aldehyde: 1.38 kilos protocatechuic-aldehyde sequently alkylating a metallic salt of these are dissolved in about three kilos spirit, to compounds of the type of para-benzyl-proto which is added alcoholic potassium hydroxid catechuic-aldehyde, and, third, separating the solution containing 0.56 kilos potassium hy protocatechuic - aldehyde-meta-alkyl-ethers droxid, and 1.27 kilos benzyl chlorid are then from the aromatic protocatechuic aldehyde added to the solution and the mixture warmed meta-alkyl-ethers so formed. on the water bath for several hours. The resi The formation of the protocatechuic alde due obtained after evaporation of the alcohol 35 hyde-meta-alkyl-ethers may be expressed by is taken up with ether and the ethereal solu the following equations: tion extracted with dilute caustic-soda solu MONa, /OCHCH (1) tion. The alkaline extract can then be either 90 I. CH-OH--CHCHCl-CH-OH--(2)NaCl supersaturated with caustic-soda solution, NCH:O NCH:O(4). which precipitates the comparatively insolu 40 II. cH4855.2ch,48E:OCHCH (1) OCHCH (i. ) ble sodium salt, or it is more advantageous to NCH:O(4) \CH:O(4), first acidify, dissolve the separated cake in /OCHCH (1) /OH (1) spirit, and add just sufficient caustic-soda so 95 III. CEi-ORC2-HCl=CH-OR(2)-CH-CH.Cl lution to precipitate the sodium salt of proto NCH:O(4) NCH:O(4). catechuic-aldehyde monobenzyl-ether. The 45 : In the first operation the conversion into free protocatechuic - aldehyde monobenzyl the above-mentioned compounds of the type ether crystallizes out of alcohol in compact of para-benzyl-para-protocatechuic-aldehyde leaves and melts at 122 centigrade. The iso IOO is best effected in the following manner: One meric-meta-benzyl-ether that is formed at the molecular proportion of alkaline hydroxid, or same time melts at 113 to 114 centigrade. it may be earth alkaline hydroxid, or it may The production of para-benzyzl-protocate be an alkali salt or earth alkali salt of car chuic-aldehyde may also more advantage bonic or phosphoric acid, is added to the al ously be carried out by dissolving the potas coholic or watery solution of protocatechuic sium salt of protocatechuic-aldehyde in water I o5

545,099 and boiling it with benzyl chlorid in a return tion of phenylbenzyl ether one kilo of para 50 condenser. benzylprotocatechuic-aldehyde-meta-methyl ether, or it may be meta-ethyl, or meta-propyl, II. Production of aromatic ethers of the type or meta-isopropyl, or meta-isobutyl-ether, is of para-benefl-protocatechnic- aldehyde heated on a Water bath with concentrated meta-alkyl-ether. hydrochloric acid and frequently stirred. 55 1. Para-benzyl-protocatechuic-aldehyde Decomposition into benzyl chlorid and the meta-methyl-ether: For example, 2.28 kilos respective protocatechuic - aldehyde - meta para-benzyl-protocatechuic-aldehyde and 1.5 alkyl-ether is thus effected. Both bodies are O kilos methyl iodid, dissolved in ten kilos separated by known methods. Protocate methyl alcohol, are warmed for some hours on chuic-aldehyde-meta-ethyl-ether crystallizes the water bath with a solution of 0.56 kilos from water into small glittering scales. (Melt potassium hydroxid in methyl alcohol. The ing-point, 77.5 centigrade.) Protocatechuic para -benzyl protocatechuic-aldehyde-meta aldehyde-meta-propyl-ether crystallizes from methyl-ether so formed is isolated in the ordi water into fine needles. (Melting-point, 82° nary Way. centigrade.) Protocatechuic-aldehyde-meta 2. Para -benzyl-protocatechuic-aldehyde isopropyl-ether represents a thick oil. Pro meta-ethyl-ether: For example, 2.28 kilos of tocatechuic - aldehyde - meta-isobutyl-ether para-benzyl-protocatechuic-aldehyde and 1.6 crystallizes from watery spirit into long nee kilos of ethyl iodid, dissolved in ten kilograms. dles. (Melting-point, 94 centigrade.) It is of ethyl alcohol, are kept for a few hours in to be observed that para-benzyl-protocate a water bath with an alcoholic solution of chuic-aldehyde, as well as the compounds re caustic potash containing 0.56 kilograms of ferred to (sub. 1, 2, 3, 4, 5) and the respective KOH. After evaporating the spirit the small protocatechuic-aldehyde - meta-alkyl-ethers 25 portion of unattacked parabenzyl-protocate obtained thereof represent new products. chuic-aldehyde is removed by Washing the Having thus described my invention and in 75 ethereal solution of the raw product with what manner it is to be carried out, what I caustic-soda solution. After evaporation of claim as new therein, and desire to secure by the ether the para -benzyl-protocatechuic Letters Patent, is meta-ethyl-ether remains behind as an easily The process of obtaining protocatechuic al solidifying oil. This ether crystallizes from dehyde meta-alkyl-ethers, which consists in spirit into small crystals. (Melting-point, 57 causing a suitable compound of the type of centigrade.) In the same way there were ob benzyl chlorid to act upon a monometallic salt tained: of protocatechuic-aldehyde, alkylating a salt 3. Para -benzyl-protocatechuic-aldehyde of the so formed compounds of the type of 35 meta-propyl-ether, which crystallizes from para - benzyl protocatechuic-aldehyde, and spirit into compact small crystals of rhombic separating from the compounds of the type of appearance. (Melting-point, 74 centigrade.) para-benzyl-protocatechuic aldehyde-meta 4. Para -benzyl-protocatechuic-aldehyde alkyl-ether thereby obtained the protocate meta-isopropyl-ether, (representing a thick chuic-aldehyde-meta-alkyl ethers by decom position, such as by means of hydrochloric or oil.)5. Para -benzyl-protocatechuic aldehyde hydrobromic acid, substantially as set forth. meta-isobutyl-ether, which crystallizes from In testimony whereof I have hereunto set ligroin into long silk-glittering needles. (Melt my hand this 30th day of June, 1894. 45 ing-point, 42.5 centigrade.) ALBRECEIT SCHMIDT. III. Production of the protocatechuie - alde Witnesses: hyde-meta-alkyl-ethers. W. HAUPT, For example, analogous to the decomposi E. GRUNWELL,