US2195198A - Benzene carboxylic acids alkylated in the nucleus and process of preparing them - Google Patents

Description

Patented MarQ ZG,

i v BENZENE oAnBo 2,195,198 c b xYLIc A IDSALKYLATED IN THE NUCLEUS AND'PROJCESS PRE- TARIN'G fr'HEM I Gerhard Balle andI-Iermann Wagner, Frankfort-' on-the-Main,

and ,Eberhard Nold, Ludwigs-' haf en-on-the lthine, Germany; assignors to *I. G. Farben'indus'trie Aktiengesellschaizt,- H Frankfort-on-tlie Main, Germany Y No Drawing. Application June's, 1938, Serial Nor I 212,124. In Germany June,7, 1937 4Claims. (c1. zoo-e515) The-present invention relates to benzene carboxylic, acids alkylated in'the nucleus and to a process of preparing them;

Attempts to introduce yet been unsuccessful. i

I having at least four carbon atoms, with ally-1 -'15 We have found tha corresponding acetophenones or omega haloe genacetophen'ones', which are substituted in the nucleus by one or several aliphatic orcyclo-'.,

aliphatic hydrocarbon radicals having, together at least eight carbon atoms and one of which pohalogenite solution, that are solutions of salts of, for instance, hypochlorous or .hypobromous acid, to form'the corresponding benzene car boxylic acids, the hydrocarbon radicals present l as side chains beingpractically unattack'edsw The substituted acetophenones or omega halogenacetophenones are obtained in knownmanner-by condensing an acetic acid halide on. halogen-acetic acid halide :with a substituted.

hydrocarbon of the benzene series. Examples of the latter are the homologous alkyl benzenes obtained by catalytic reduction of the araliphatic ketones which are obtainable from hydrocarbons of the benzene series and higher fatty acid halides; furthermore, condensation products of benzene hydrocarbons with higher aliphatic or -cycloaliphatic olefines, alkyl'halides andchloring ation productsobtained from hydrocarbon mixtures containing hydroaromatic hydrocarbons as they are obtained in the hydrogenationof coal and the like. b i

The oxidation of the substituted acetophonones or omega-halogen-acetophenones is preferably carried out in a dilute solution .at temperatures" comprising room temperature up to about 100 preferably at 70 C. to 80 C;,'- s o= that at; least part of the carboxylic acid salt obtained passes into solution. It is not necessary to start from pure (distilled) acetophen'one derivatives or omega-halogen-acetophenone derivatives. When using crude dark condensation products with acetic acid halide 01'- halogenacetic acid halide (if desired, after the elimination of the unchanged starting materials and of by-products having a low boiling point) it is advisable to work with an excess of hypohalogenite solution by which the dark products are bleached and only slightly colored carboxylic acid salts are obtained. The oxidation of the omega-halogenacetophenones proceeds more rapidly and more smoothly than that of the non-halogenateddedirectly alkyl groups. l into benzoic acid or a homologue thereof have as v tobenzene carboxylic acids are obtainable in a" good yield by oxidizingthe 1 rivatives. from the solutionof their salts by acidifying with dissolving them in alkalies; by evaporation and drying the salts are obtained in theform of white to. light-brown powders.

The benzene carboxylic acidsv or the salts thereof thus obtained, particularly those containing as substituents hydrocarbon radicals of at least twelve carbon atoms, are soap-like prodacts and may be used instead of 'soa'ps'or as ad-v ditions to soaps.' The products are likewise valuable intermediate products for thefpreparation of textile adjuvants and the like Y The following examples "serve to illustrate the invention, but they are not intended to limit it thereto, the fparts'being byiweight and the ratio of parts by volumeand parts byweight is that-2d (l) lAmixtu're of 33 parts of acetyl chloride and 100 parts of n-dodecylbenzene,. obtained by catalytic reduction of laurophenoneare {introduce'dlinto a'sus'pen'sion of 154parts of aluminium hich exists between the liter and the kilo:

chloride (anhydrous) in1about200 parts of car- The 'carboxylic acids are precipitated mineral acid or. acetic acid, separatedv from the I liquid and, if; desired, reconverted into salts by bon, tetrachloride, while cooling and stirring;

after some hours the whole ispoured'on ice,

worked up cent., meltingpoint 4891C). v

100 parts of n'.-dodecylacetoph'enone are. gradually introduced 'at about C to, '8,0 C. into 2550.parts by" volume of a sodium hypochlorite solution of 3 per cent. strength orjthe; equivalent quantity of. potassium hypochlorite solution and,

stirred at thisutemperatureuntil atestportion An excess of hy.. present is decomposed The n-dodecylbenzoic has become soluble in water. pochlorite which may be with the aid of bisulfite.

acid is separatedin the'form of asolid product ",inthe usual manner and distilled" underl reduced" pressure. (Yield 70 00 .75 per i t which-gas regardsits "appearance; resembles the fattyacids, by acidifying it with dilute mineral acid or acetic .acid. After washing with water the product is dissolved in the calculated amount of hot dilute sodiumcarbonate solution or caustic soda solution; after evaporation the sodiumparadodecylb-enzoate is obtained in the form of a white-powder; The yield amounts to per cent.

Small amounts of unchanged parent material may be removed with the aid of-solvents, for instance, petroleum ether. The sodium salt produces soap-like solutions; the product is; however, sparingly soluble in cold water. The calcium salts and barium salts as well as the heavy metal salts are very sparingly soluble in water.

The free acid is soluble in organic solvents. for instance, in benzene hydrocarbons, halogen hydrocarbons, and alcohols. v

(2) To a suspension of. 53, parts of aluminium chloride (anhydrous) in about 300 parts of carbon tetrachloride there is added, while stirring below +10 C., a mixture of i l parts of ch1or= acetyl chloride and 100- parts of alkyl benzene (molecular weight about 260, corresponding to an average chainlength of the alkyl substituents of. Bio 14 C-atoms) obtained by condensation of benzene with a chlorination product of a hydrocarbon mixture, containing hydroaromatic compounds and boiling under a pressure of 20 mm.

mercury at 50 C. to 125 C., as it is obtained in the hydrogenation of lignite. After a subsequent stirring for 12 hoursthe whole is poured on ice at room temperature. After washing and drying the condensation product the readily volatile by-products are distilled up to a boiling point of about 130C. under a mercurial pressure of 6' mm. 112 parts of this crude alkylated omega-chloracetophenone are introduced at about 80 C. into 2509 parts of an industrial sodium hypochlorite solution of 3 per cent.

strength and kept at this temperature until the hypochlorite has been consumed. Thereactiou is promoted byxadding a small quantity of sodium salt of the corresponding alkyl bcnzoic acids to the 'hypochlorite solution as emulsifying agent. After addition of some animal charcoal the whole is filtered hot froinsmail amounts of resinous by-products and lay-acidifying the light brown filtrate there is obtained a mixture .of alkylated ,benzoic acids (average molecular weight about 390, corresponding to an average chain length of the alkyl substituents of ,13 to 14 C-atoms) in the form of a massresembling resinicacid and capable of being-pulverized at temperatures below. 1+10 C., but viscous when j hot. If desired, this mass is dissolved in dilute alkali and the salts are obtained in'the form of a light-brown powder having properties resembling those of resin soaps. (Theyield amounts to 105 parts.)

(3) Tea mixture containing 100 partsof fdi-. tertiary-butylbenzene, about 200, parts of carbon tetrachloride and 60 parts of chloracetylchloride. there are' gradually introduced below +10C.,

while stirring, parts ofanhydrous'aluminium chloride; the whole is subsequently stirred for several hoursat about 25 C., poured on ice and worked up, in the usual manner. parts of a condensation product freed from more "easily boiling portions by distillation toa boiling point t of about C. under a pressureof 5 mm. areoxidised (as described in Example 1) with 2000 parts of a sodiumhypochlorite solutionofB per cent. strength or the" equivalent amount of so..

dium hyprobromite solution and worked up.-

The sodium'salt of the di-tertiary-butylbenzenecarboxylic acid isobtained in the form of awhite powder in a yield of about 70 per cent. of the amount calculated for the di-tertiary-butylbenzene used. 7

The free acid is prepared from'the salts as indicated above. The crude product contains as impurities alkylbenzoic acids which are formed by the alkyl radical in the di-tertiary-butylbenzene being split ofi by the influence of aluminium chloride; after recrystallization from methanol the di-tertiary butylbenzoic acid melts at 128C. I

(4) To a mixture from 400 parts-of the alkyl benzene mixture, obtained by condensation of diisohexylene and benzene by means of boron I fluoride-phosphoric, acid and distillation of the easily boiling portions up toa boiling point at 110 C. under a mercurial pressure of 15 mm. (molecular weight 213), about 200 parts ofcarbon tetrachloride and 100parts of bromacetylbromide; there are gradually introduced, while stirring, below ,+10 C. 65 parts of aluminium chloride (anhydrous). The whole is stirred for several hours at about 25 C., poured on ice and worked up in the usual manner 100 parts of the condensation productfreed from, the easily boiling portionsby distillation up to a boiling pointof about -C. under a mercurial pressure of.3'mm. are oxidized with 1900 parts of sodium phyochloritesolution of' 3 per cent. strength or the equivalent amount of a potassium hypobromite solution (as, indicated'in' Example 1) and worked up., By acidifying with mineral acid or acetic acid a mixture of alkyl benzoic acidshaving an acid number of about 230 is obtained in the form of a brownish partly solid mass. The alkali or. ammonium 'saltsof this acid mixture yield foaming aqueous solutions. The salts of alkaline-earth metals and heavy metals are difilcultly soluble in water even in the warmth.

We claim:

1.v The n-dodecylben zoicacid which is soluble in benzenehydrocarbon, halogenv hydrocarbons and alcohols and the sodium salt': of which being a white powder soluble in water to a soap-like solutiomwhereas' its salts of calcium, barium and of the heavy metals are diflicultly'soluble in water. 1

2. The benzoic acid of the formula: I

R standing for saturated hydrocarbon radicals of 13 to 14 carbon atoms, beinga resinic acid- 4. A mixture of alkyl. benzoic acids having an acid number of about 230'andbeine, a brownish partly solid mass.

.GERHARD- .BALLE, HERMANN WAGNER, EBERHARD NOLD.