US2472276A - Process for the production of aryldesoxyglycoses and diaryldesoxy-alditols - Google Patents

Description

Patented June 7, 1949 TED STATES PATENT" OFFICE PROCESS FOR THE PRODUCTION OF'ARYIQ- DESO-XYGLYCOSES AND DIARYLDESOXY- No Drawing. Application December 31, 1945,. Serial No. 638,583

8 Claims. 1 This invention relates torthe. production of new classes of organic chemical compounds; and more particularly to a. process for. the production of aryldesoxyglycoses and; diaryldesoxyalditols and derivatives thereof. The object of'thepresent inl omen A specific example of a derivative of an aryldesoxyglycose obtained by the process of. the present invention is tetraacetyl-D-glucopyranosylb-enzene; An alternate name for this compound is l-phenyl-l-desoxy-2;3 4,6 tetraacetyl- D-glucose. It may be represented by the following structural formula:

CuHa

$.11 v Hall AcO( 3H I HCOAc i omoAc Further examples of aryldesoxygly-coses andi 2 derivatives obtained by the process of the present invention include D-xylopyranosylbenzene (or l-phenyl-l-desoxy- D-xylose') 'I'riacetyl-D-xylopyranosylbenzene D-galactopyranosylbenzene (or l.-pheny1-1-des oxy-D-galactose) Tetra'acetyl-D-galactopyranosylbenzene p-D-glucopyranosyltoluene' (or. l-tolyl-l-desoxy- D-glucose) p(Tetraacetyl-D-glucopyranosyl) toluene The second of the new classes. of compounds, L e., diaryldesoxyalditols, obtained by the process of the present invention may be. represented" by the following general formula whereinA'r and, Ar represent aryl radicals,- and n is a, whole number, usually 3 or 4.

Ar-GHe-Ar' (chomp A specific example. of a diaryldesoxyalditol is 1,1-diphenylI-4-desoxy-D-glucitol. This may! be representedby the following structural formula:

'Q u EM H on 110611 HC'OH HCOH A specific example of a, derivative. of a diaryldesoxyalditol is 1,1-diphenyl-I-desoxy-2;3;i'.5,fipentaacetyl-D-glucitol. This may be represented by the following structural formula:

Further examples of diaryldesoxyalditolsa include 1,11-di-p-toly1-1-desoxy-D -glucito1 1,1-diphenyl-l-desoxy-D-galactitol 1,1-diphenyl-I-clesoxy-D-xylitol The, above aryldesoxyglycoses: and diawltiesoxyalditols may be produced according: to the present invention by' bringing about; the reaction between a carbohydrate derivative possessing certain hereinafter specified characteristics and an aromatic hydrocarbon or specific substitution product thereof in the presence of anhydrous aluminum chloride.

The above reaction will be recognized as involving an adaptation of the Friedel-Craits reaction. While the Friedel-Crafts reaction is well known, it is surprising that it has never been applied to carbohydrate derivatives and aromatic hydrocarbons to produce aryldesoxyglycoses and diaryldesoxyalditols.

The reaction of the present invention s believed to proceed according to the following illustrative equation, involving the use, in this instance, of an aldohexose derivative as one of the reactants,

wherein Ar represents an aryl group; Y represents chlorine, bromine, or an acyloxy group; and

,R represents an alkyl group. The CHOH groups represented in the above formulae actually do not appear until water has been added to isolate the desired products, as will be described later. The are probably held by the aluminum chloride in the following manner CIIOAlClz. The diaryldesoxyalditols are actually formed by the reaction of aryldesoxyglycose with aromatic hydrocarbon in the presence of aluminum chloride.

In carrying out the present invention there may be used as one of the reactants any carbohydrate derivative containing an aldehydic or ketonic function, the carbon atom of which has attached to it a group Y; Y, as already mentioned, may be chlorine, bromine or an acyloxy group. The term carbohydrate derivative as used herein and in the appended claims is intended to refer to a compound obtained from the carbohydrate, wherein the skeleton of the carbohydrate (i. e., the carbon chain) remains substantially intact. The term derivative is thus to be distinguished from a modification in which the original carbohydrate skeleton may be degraded or increased or otherwise changed. The term acyloxy as used herein and in the appended claims is intended to refer to an acyl group holding an oxygen. In general, any aldose or ketose in which the carbon atom of the aldehydic or ketonic function has attached to it a group Y as above defined is satisfactory. Polyacylglycosyl halides or acetates are generally suitable. Examples of carbohydrate derivatives which may be employed in the process of our invention include the alpha or beta forms of glucose pentaacetate, xylose tetraacetate, fructose pentaacetate, arabinose tetraacetate, galactose pentaacetate, mannose pentapropionate. The halogen derivatives of carbohydrates which may be used in the process of this invention include tetraacetylglucosyl chloride, tripropionylarabinosyl b r o m i d e and tetraacetylfructosyl chloride.

In carrying out the invention both substituted and unsubstituted aromatic hydrocarbons may be used. Among the aromatic hydrocarbons which may be used in the process of the present invention are benzene, toluene, xylene, naphthalene. Compounds such as bromobenzene, anisole, thiophene and the like may be used also. In fact any of the type of substituted or unsubstituted aromatic hydrocarbons which are known to undergo the Friedel-Crafts reaction in general may also be used here. As the term hydrocarbon is used herein in the description and claims, it is intended to refer to both substituted and unsubstituted hydrocarbons.

The amount of aluminum chloride which is used as a catalyst in the process of the present invention is an important factor. In order to effect the reaction between carbohydrate derivatives and aromatic hydrocarbons in accordance with the present invention, it is necessary to use at least about x+1 molecular equivalents of aluminum chloride, with respect to the amount of carbohydrate derivative where :1: equals the number of substituents, such as acyl and the like, on the carbon atoms other than the aldehydic or ketonic function. Considerably larger amounts of aluminum chloride may be used also, although there is no advantage in using more than about 6 to 8 molecular equivalents of aluminum chloride for a pentose derivative, 8 to 10 for a hexose derivative, or 10 to 12 for a heptose derivative.

The amount of aluminum chloride used as catalyst in the reaction between the above specifled carbohydrate derivatives and aromatic hydrocarbons determines the relative proportions of aryldesoxyglycoses and diaryldesoxyalditols, respectively, which are formed. As already mentioned, aryldesoxyglycoses react with aromatic hydrocarbons in the presence of aluminum chloride to form diaryldesoxyalditols. If the mini.- mal amount of aluminum chloride is used, a relatively large amount of aryldesoxyglycose will be formed while the amount of diaryldesoxyalditol will be relatively small. If, however, larger amounts of aluminumchloride, e. g., about 8 to 10 molecular equivalents for a hexose derivative, are used, then the diaryldesoxyalditol will be formed in much larger quantities than the aryldesoxyglycose, i. e., the diaryldesoxyalditol becomes the primary product.

In carryin out the process of the present invention, the carbohydrate derivative reactant is mixed with an excess of an aromatic hydrocarbon and to this mixture is added anhydrous aluminum chloride. This mixture is heated with stirring until the reaction. is complete. Hydrogen chloride gas is evolved copiously at first but subsides as the reaction continues. During the reaction, the aluminum chloride changes from a powder to a light gum and eventually dissolves in the aromatic hydrocarbon which in addition to being one of the reactants also serves as the reaction medium. After the reaction is complete, the mixture is allowed to cool and is then mixed with several volumes of cold water. This treatment causes the disappearance of the CHOA1C12 complexes and the appearance of the CHOH groups in the aryldesoxyglycose and diaryldesoxyalditol. Two layers are formed, an aqueous layer and a non-aqueous layer. These are separated in any suitable manner. Both aryldesoXyglycose and diaryldesoxyalditol are found in the aqueous layer. The catalyst, now in the form of a soluble aluminum salt, is also found in this layer. The aromatic ketone, i. e., the ArCOR in the above. equation together with the excess hydreams drocarbon and higher boiling, tarry products appear in the non-aqueous layer. The keto-nemay be separated from the non-aqueous layer and purified by vacuum distillation or other suitable means. The excess of aromatic hydrocarbon may be recovered in similar manner.

The recovery of the desired products from the aqueous layer is effected by first addin thereto an alkaline substance, such as sodium hydroxide, in amountsufficientto adjust the pH value thereof to about 7.0. This treatment produces aluminum hydroxide which is then removed, by filtration-or the like. The water is then removed from the remaining filtrate, as by evaporation under diminished pressure. There then remains a dark colored sirup. In addition to the desired products, this sirup contains inorganic salts.

The treatment of the sirup for the recovery of aryldesoxyglycose and diaryldesoxy-alditol therefrom may vary with the respective amounts of each of these twoproducts present. In cases when the amount oi catalyst used is sufiicient to produce diaryldesoxyalditol in large quantity, it is usually preferable to isolate this compound first.

This may be efiected by first treating the siru p With a solvent for aryldesoxyglycose and diaryldesoxyalditol, such as pyridine, to obtain an extract and then removing such solvent from the extract. This step separates the desired products from the inorganic salts and is optional.

After removal of the solvent a sirup again remains. The sirup whether previously treated with the solvent or not is then dissolved in only as much hot Water as is necessary for this purpose and the solution allowed to cool. The diaryldesoxyalditol being considerably less soluble in water than the aryldesoxy'glycose will crystallize from the solution upon cooling while the aryl-d'esoxyglycose remains in solution. The crystals, after separation, may be recrystallized from.

Water for further purification. The mother liquor remaining after the diaryldesoxyalditol has been removed is evaporated to dryness, leaving a colored siru-p, containing the aryldesoxyglycose. As an optional step, this sirup may be treated with a suitable solvent. such as Z-propanol to obtain the aryldesoxyglycose in pure form; removal of the solvent leaves the aryldesoxyglycose, either in solid form or as. a sirup.

It is. often desirable to recover the aryldesoxyglycose in the form of a derivative thereof, such, for example, as the acetate. This derivative may be formed by treating sirup containing or consisting of aryldesoxyglycose, according to known procedures, with acetic anhydride and sodium acetate. After the addition of water to hydrolyze theexcess acetic anhydride, the acetylated product or acetate derivative of the aryldesoxyglycose may be extracted from the mixture by means of a suitable solvent such as ethyl ether. The ether extract is washed and decolorized in suitable manner and then the ether is removed therefrom. There then remains thev acetate of the aryldesoxyglycose usually in solid form. This solid may be recrystallized from a suitable-solvent, such. as Z-p-ropanol. If desired, the acetate of the aryldesoxyglyco-se may be deacetyl'ated according to .lmovvn procedures by means of sodium and methanol. After deacetylation is complete the solution remaining is evaporated to dryness, leaving the. .aryldesoxygly-cose.

In cases when the sirup first above mentioned contains the aryldesoxyglycose in large quantity or when both .products are present. in isolable quantities, the sirup may advantageously be treated, aswith-acetic anhydride and sodium acetate, to form acetate. derivatives of both. thearyldesoxyglycose and the diaryldesoxyalditol. After hydrolysis to decompose excess acetic anhydride the acetylated products may be extracted from the mixture by means of a suitable solvent, such as ethylether. Removal of the ether leaves a sirup containing the acetates of :both'the desired products. These may be separated by fractional crystallization from a suitable solvent, such as 2-propanol. Each of the acetates may then be deacetylated in themanner previously described.

The process of the present invention may be carried out in any reaction vessel which is equipped with suitable means for agitation and to allow for the escape of hydrogen chloridegas as it is evolved and also to allow the. reactionmixtureito be maintained at suitable reaction temperature without the lossof the reactants, particularly the aromatic hydrocarbon.

The temperature atwhich the reaction mixture should be heated will depend. upon the ingredients therein, but in general should not exceed about 0. Generally, temperatures equivalent to thoseobtained byhea'ting, thereaction mixture on a steam bath are satisfactory.

Each of the reactants. and also the catalyst should bein anhydrous form in order to carryout the reaction properly. The commercial grade of anhydrous aluminum chloride used for catalytic purposes is satisfactory for purposes of. the :present. invention- 'Thebull-r of the catalyst should be added at. the beg-inning :if it. is. desired not. to add all of the catalyst at one time.

The time required for the reaction to takeiplace will. depend upon the individual reactants present, but generally a iperiod of heating, under conditions: as above. described, for 4 to 8 hours is satisfactory.

excess of thearomatio hydrocarbon should be used the hydrocarbon is intended to serve s the reaction medium. Generally, the excess should be equal to at least about '60 times the amount of the hydrocarbon actually undergoing reaction- Asralready mentioned, the excess hydrocarbon maybe recovered. Other solvents, such-as carbon disulfilde, which are known to-serve as reaction media for the Friedel-Crafts reaction, may alsobe used here for such purpose.

The carbohydrate derivative should be at least partially, if notxcompletely soluble in the aromatic I hydrocarbonvvith which reaction is to be effected,

orin .a. common solvent-for both reactants which may .serve as, a reaction. medium. The introduction of. substituentgroups, such as a'cyl, valkyl and the. like, on the-carbonatomsother than the carbonof the aldehydic or ketonic functional group an efi'ective means of imparting'the desired-solubility characteristics to the carbohydrate derivative;

The amount of water added todecompose the aluminum complex should preferably belarge enough tin/dissolve the GESiIB'd'IDIOdllf-HZSL. In some cases: the diaryldesoxyalditol may be rather insoluble water. as compared to :aryldesoxyglycoses which arevery soluble and inorder to-isolate the desired compounds easily, it is preferable to have them bothin the water layer.

The: adjustment offithe pHmay be effected by a variety of, alkaline substances. .Sodium hydroxide,v Potassium hydroxides sodium carbonate, ammonium hydroxide and the like are satisfactory for this purpose.

Other "derivatives;than the acetatemay-abe used to isolate. the, aryldesoxyglycose. Among these traction with ether.

7 may be'mentioned'the propionate; butyrate, benzoate and the like. The diaryldesoxyalditol is preferably isolated as such but suitable derivatives such as the acetate, propionate, butyrate and the 'lation above referred to include benzene, ethyl acetate, chloroform and the like.

The following examples which are intended as informative and typical only and not in a limiting sense will further illustrate the invention, which is intended to be limited only in accordance with the scope of the appended claims.

Example 1.Preparation of 1 -phenyZ-1-deso:z:y- 2,3,4,6-tetraacetyZ-D-glucose. A mixture consisting of 20 grams (0.055 mole) of 2,3,4,6-tetraacetyl-D-glucosyl chloride in anhydrous condition; 300 milliliters (3.39 moles) of benzene which had been dried over calcium chloride; and 38 g. (0.28 mole) of anhydrous aluminum chloride containing of alumina was placed in a three necked flask. The flask was equipped with means for mechanical stirring, means for refluxing the mixture and for absorption of hydrogen chloride gas, and means for introducing more catalyst, if desired. The mixture was heated on a steam bath under reflux conditions and with mechanical stirring for 4 hours. Then 5 g. more of anhydrous aluminum chloride was introduced, and refluxing was continued for 3 hours more. Then the mixture was allowed to cool, and thereafter was poured into 500 ml. of cold water. The two layers formed upon addition of water were separated.

The benzene layer, after being washed with alkali solution and water, dried over sodium sulfate and filtered, was distilled. Upon fractionation of the 15.8 g. of oil which remained after 4 removal of benzene, 11 g. of acetophenone, 3 g. of

material boiling at 240-250 C. (at 110 mm. pressure) and 0.5 g. of residue were obtained.

To the water layer was added sodium hydroxide i until the mixture was neutral to litmus. It was then filtered to remove aluminum hydroxide. The aluminum hydroxide cake was washed with water and the washings added to the filtrate remaining after removal of aluminum hydroxide. water was removed from the combined filtrate and washings by distillation under diminished pressure. The residue remaining weighed about 50 g. and contained a large amount of sodium chloride. The l-phenyl-l-desoxy-D-glucos'e was extracted from the residue by treatment thereof three times with 200 ml. portions of hot pyridine. After the pyridine was distilled ofi from the extract there remained 5.6 g. of crude l-phenyl-ldesoxy-D-glucose in the form of a brown sirup. This was acetylated by adding thereto 40 ml. of acetic anhydride and 2 g. of sodium acetate and heating the resulting mixture with agitation for 2 hours on a steam bath. The excess of acetic anhydride was removed by adding water to the mixture, thereby hydrolyzing the acetic anhydride.

The desired product above mentioned, now in acetylated form, was recovered from the mixture, after hydrolysis of the acetic anhydride, by ex- The ether extract was The.

diminished pressure.

washed with water, then with 4% sodium hydroxide (which removed most of the color), again with water, and finally dried over sodium sulfate. Decolorization of the ether extract was efiected by pouring the same through a bed of decolorizing carbon supported on a filter aid. Evaporation of the ether from the extract left 6.0 g. of white solid. This solid wa purified by dissolving it in hot 2-propano1 and allowing it to crystallize therefrom. This procedure was repeated two times more. The purified crystals were identified as 1-phenyl-l-desoxy-D-glucose tetraacetate or l-phenyl-1-desoxy-2,3,4,6-tetraacetyl- D-glucose. The melting point thereof was 156.5 C. and (00 in chloroform was -16.4 (conc. 0.855 g./ ml. of chloroform).

Oxidation of the tetraacetate of l-phenyl-ldesoxy-D-glucose with potassium permanganate produced benzoic acid. The tetraacetate exhibited no reducing power when tested with Fehlings solution.

Deacetylation of l-phenyl-l-desoxy-D-glucose tetraacetate was effected by dissolving 0.3 g. thereof in 60 ml. of methanol and adding thereto a small piece of sodium. The mixture was permitted to stand for 3 hours. Then the alcohol was removed by evaporation on a hot water bath. There remained 0.2 g. of white powder, l-phenyll-desoxy-D-glucose.

Example 2.--Preparation of 1,1 -diphenyZ-1- desoxy-2,3,4,5,6-pentaacetyZ-D-glucitol. A mixture consisting of 118 g. (0.311 mole) of 2,3, 1,6- tetraacetyl-D-glucosyl chloride, 1800 ml. (20.3 moles) of dry benzene, and 347 g. (2.61 moles) of anhydrous aluminum chloride was heated on a steam bath under conditions of refluxing and stirring for 2 hours. Then 20 g. more of aluminum chloride was added and the mixture was stirred and heated for 4 more hours, and then was left over night to cool. The hydrogen chloride which escaped was absorbed in water after being conducted through the reflux condenser and a calcium chloride tube. As the reaction progressed the color of the solution became dark red, and the aluminum chloride layer changed from its powdery form first to a light gum, and finally to a dark sirup.

The contents of the reaction vessel were poured into about 3 liters of cold water to decompose the aluminum chloride complex. The water and benzene layers which formed thereupon were separated. The benzene layer was washed with 10% sodium hydroxide solution, then with water, then dried over sodium sulfate, and distilled. In addition to the excess benzene recovered, there was collected 115.1 g. of acetophenone. Anthracene was isolated from the higher boiling residues.

To the water layer was added the hydroxide washings mentioned above. Then the pH value of said layer was adjusted to approximately 7.0 by means of sodium hydroxide. The large bulk of aluminum hydroxide resulting was removed by filtration through a filter aid, the filter cake being Washed repeatedly with water. The clear filtrate obtained was concentrated on a steam bath under diminished pressure until a solid residue, chiefly sodium chloride, appeared. This was extracted several times with pyridine. The pyridine was removed from the extract by distillation under There was obtained 37-38 g. of a residue from which separated some crystals of 1,1-diphenyl-l desoxy-D-glucitol, M. P.

The above mass was acetylated by adding thereto 240 ml. of acetic anhydride and 13 g. of

sodium acetate and heating for two hours at 100 C. The mixture was poured into about 1500 ml. of water-and allowed to stand for hours. On extraction of the mixture with ether, followed by evaporation of ether from the extract, 31.6 g. of a thick, amber syrup was obtained. This was dissolved in -hot Z-propanol. Upon cooling, 23.5 g. of 1,1-diphenyl-l-desoxy-D-glucitol pentaacetate of 1,1-diphenyl-1-desoxy-2,3,4,5,6-pentaacetyl-D- glucitol, M. F. 90-95 0., separated and was recovered from thealcohol. After repurification in 2-propanol the melting point of the pentaacetate was -95-95.5 C.

Oxidation of 1,1-diphenyl-l-desoxy-D-glucitol pentaacetate with alkaline permanganate produced benzophenone.

Example 3.-Deacefylation of ll-diphenyZ-I- desoxy-D-glucz'tolpentaacetate. The pentaacetate (31.7 g.) obtained according to the process described inExample 2 dissolved in methanol (400 ml.) at 25 C., and freshly cut sodium (about 0.2 g.) was added. After the mixture was allowed to stand for 45 minutes the flask in which the same was contained became filled with small white crystals. After 2 hours these were filtered. They were washed by suspending them in methanol (150 ml.) and refiltering. The yield was 18.4 g. of fine, white needles. Concentration of the mother liquid yielded 1.7 g. more of the crystals. The two crops of crystals were combined and recrystallized from boiling water (2000 ml). The melting point of the purified product was found to be 157.5-158 C., with preliminary crumpling to a powder at 140-150" C. The compound was identified by suitable analysis as 1,1- diphenyl-l-desoxyglucitol hydrate. Oxidation of the compound by means of alkaline permanganate produced benzophenone.

Example 4.Pre.paration of trz'acetyZ-be-ta-D- xylopy'ranosylbeneene and 1,1-diphenyZ-1-desoxy-D-xylitol. A mixture of 1,2,3,4-tetraacetyl- D-xylose g.; 0.063 mole), dry benzene (300 ml.; 3.39 moles) and anhydrous aluminum chloride (30 g.) was heated under reflux, as in Example 1, for 2 hours. In this example, however, all of the catalyst was added at the beginning. Acetylation of the sirup obtained from the water layer (after pyridine treatment) yielded 0.82 g. of a light, amber sirup. This was dissolved in hot 2- propanol and the solution permitted to cool. There was obtained 0.17 g. of white needles. M. P. 166-167 C. After recrystallization from 2-propanol the melting point of the crystals was raised to 169.5 C. Another recrystallization failed to raise the melting point. The above compound was identified as triacetyl-beta-D-xylopyranosylbenzene. (a) in chloroform was found to be -57.7 (conc. 0.390 g./100 ml. of chloroform).

Oxidation of the triacetylxylopyranosylbenzene with alkaline permanganate produced benzoic acid.

The solvent was removed from the mother liquor remaining after separation of the triacetylxylopyranosylbenzene. The residue (0.65 g. of sirup) was deacetylated by adding thereto 25 ml. of methanol and a small chip of sodium, and permitting the mixture to stand 2 hours. Removal of the methanol in vacuo left 0.43 g. of a yellow sirup. This was dissolved in hot water, concentrated in an air stream until solidification began, redissolved in water and the solution clarified by passing it through a decolorizing carbon sup ported on a filter aid. Further concentration of the solution resulted in about 0.1 g. of fine, white needles. These were identified as 1,1-diphenyl-1- x which set to a hard glass.

10 desoxy-D-xylitol. After recrystallization from water the crystals melted at 1'67-168 C.

Oxidation of 1,1-diphenyl-l-desoxy-D-xylitol with alkaline permanganate produced benzophenone.

Example 5.-Preparation of 1,1 -dz'phenyZ-1-desoxy-D-glucitol pentaacetate. Beta-D-glucose pentaaoetate (20 g.; 0.05 mole) dry benzene (300 ml. 3.39 moles); and anhydrous aluminum chloride (45 g.; 0.337 mole) weretreatedaccording to the method described in Example 1 except all of the catalyst was added at the beginning. The reflux period was 5 hours, 30 minutes.

From the benzene layer was obtained 11.4 g. of

- acetophenone and 9.6g. of residual tars.

From the water layer, after pyridine extraction, was-obtained-4.38 g.-of an amber sirup. This was fractionally crystallized from 2-propanol. There was obtained 0.4 g. of 1,1-diphenyl-l-desoxy-D- glucitol pentaacetate and 030g. of tetraacetyl-lphenyl-l-desoxy-D-glucose.

Example 6.Preparati0n' of 1,1-di-p-toZyZ-1- desoxy-D-glucitol. Tetraacetyl-D-glucosylch10- ride (20 g; 0.054 mole); drytoluene (362 ml.; 3.4

., moles); and anhydrous aluminum chloride (45 g.) were treated in accordance with the method described in previous examples. The heating period was 5'hours at 75-80" C.

From the toluene layer was obtained 20ml. of methyl p-tolyl ketone and 20 ml. of pungent, black tar.

From the water layer, after extraction with pyridine, was obtained 4.0 g. of sirup. This was acetylated and yielded 3.24 g. of an amber sirup Deacetylation of 2 g. of this sirup yielded 143 g. of an amber sirup which was recrystallized from hot water. The product was identified by suitable analysis as 1,1- di-p-tolyl-l-desoxy-D-glucitol hydrate. After two recrystallizations of the product from water, the melting point of the product was found to be 1585-1605 C.

Oxidation of the product with alkaline permanganate yielded 4,4-benzophenonedicarboxylic acid.

Example 7.-Preparation of 1,1-diphenyZ-1-des oxy-D-galactz'tol and tetmacetylgalactopyranosylbenzene. Beta-D-galactose pentaacetate (20 g.); benzene (300 ml.) and anhydrous aluminum chloride (45 g.) were treated in accordance with the procedure of previous examples. The yield of acetophenone was 8.7 g. The yield of acetylated sirup was 3.7 g. This sirup was deacetylated and the resulting mixture evaporated to dryness. The residue remaining was crystallized from hot water. 1.75 g. of crystals were obtained. These were identified as 1,1-diphenyl-l-desoxy-D-galactitol. After two further crystallizations of the compound from water the melting point of the compound was found to be C. Oxidation of the compound with alkaline permanganate produced benzophenone.

The mother liquor remaining after removal of the 1,1-diphenyl-l-desoxy-D-galactitol crystals described above was evaporated to dryness leaving 0.97 g. of amber sirup. This sirup was reacetylated. There was obtained 1.24 g. of a clear, amber sirup. This was identified as tetraacetyl- D-galactopyranosyl-benzene.

No claim is made herein to either aryldesoxyglycoses nor to diaryldesoxyalditols as compounds as they are claimed respectively in co-pending applications Serial No. 638,584, filed December 1945, issued as Patent No. 2,460,803, Feb. 8, 1949, and Serial No. 638,585, filed December 31, 1945.

We claim:

1. The process which comprises effecting the reaction, under substantially anhydrous conditions, between tetraacetylglucosyl chloride and benzene in the presence of about molecular equivalents of anhydrous aluminum chloride, based upon the weight of the tetraacetylglucosyl chloride; said reaction being effected at elevated temperature, not exceeding about 100 C. and the time for efiecting said reaction being about '7 hours.

2. The process which comprises effecting the reaction, under substantially anhydrous conditions, between tetraacetylglucosyl chloride and toluene in the presence of about 5 molecular equivalents of anhydrous aluminum chloride, based upon the weight of the tetraacetylglucosyl chloride; said reaction being efiected at about 75-85 C. and the time for efiecting the reaction being about 5 hours.

3. The process which comprises efiecting the reaction, under substantially anhydrous conditions, between 1,2,3,4-tetraacetyl-D-xylose and benzene in the presence of about 4 molecular equivalents of anhydrous aluminum chloride, based upon the weight of the 1,2,3,4-tetraacetyl- D-xylose; said reaction being elfected at elevated temperature, not exceeding about 100 C. and the time for effecting said reaction ranging from about 4 to about 8 hours.

4. The process which comprises contacting, under substantially anhydrous conditions and at elevated temperature, not exceeding 100 C., a glucose derivative and an aromatic hydrocarbon in the presence of anyhdrous aluminum chloride, said glucose derivative being characterized in that there is attached to the carbon atom of the aldehydic function a substituent selected from the group consisting of Cl, Br and acyloxy and in that the glycose derivative has protected hydroxyl groups; said aluminum chloride being present in the amount of at least about 5 molecular equivalents, based upon the weight of said glucose derivative.

5. The process which comprises contacting, under substantially anhydrous conditions and at elevated temperature, not exceeding 100 C., a glucose derivative and an aromatic hydrocarbon in the presence of anhydrous aluminum chloride, said glucose derivative being characterized in that there is attached to the carbon atom of the alde- 12 hydic function a substituent selected from the group consisting of Cl, Br and acyloxy and in that glycose derivative has protected hydroxyl groups; said aluminum chloride being present in the amount of about 8 to 10 molecular equivalents, based upon the weight of said glucose derivative.

6. The process of preparing aryldesoxyglycoses and diaryldesoxyalditols which comprises contacting under substantially anhydrous conditions and at elevated temperature not exceeding C. a glycose derivative and an aromatic hydrocarbon in the presence of anhydrous aluminum chloride, said glycose derivative being characterized in that there is attached to the carbon atom of the aldehydic function a substituent selected from the group consisting of chlorine, bromine and acyloxy, and in that the glycose derivative has protected hydroxyl groups; said aluminum chloride being present in the amount of at least about az-l molecular equivalents, based upon the weight of said glycose derivative, where :r equals the number of substituents on the carbon atoms of said glycose derivative other than the carbon atom of said function.

7. The process of preparing aryldesoxyglycoses and diaryldesoxyalditols which comprises contacting under substantially anhydrous conditions and at elevated temperature not exceeding 100 C. a glycose derivative and an aromatic hydrocarbon in the presence of anhydrous aluminum chloride and selectively recovering aryldesoxyglycoses and diaryldesoxyalditols, said glycose derivative being characterized in that there is attached to the carbon atom of the aldehydic function a substituent selected from the group consisting of chlorine, bromine and acyloxy, and in that the glycose derivative contains protected hydroxyl groups; said aluminum chloride being present in the amount of at least about :c-l molecular equivalents, based upon the weight of said glycose derivative, where :1: equals the number of substituents on the carbon atoms of said glycose derivative other than the carbon atom of said function.

8. The process according to claim 6 wherein the time of contact ranges from about 4 to about 8 hours.

WILLIAM ANDREW BONNER. CHARLES D. HURD.

No references cited.