I was able to find 3 articles by Dolgov and collaborators on F-C reactions using a catalyst comprised of Al shavings treated with dry HCl gas in benzene. This catalyst appears attractive because of its easy preparation and good activity (notice how little catalyst is used compared to ordinary AlCl3 in standard preparations).
Here are major portions of Dolgov's 3 articles on this catalyst that I was able to find in J. Chem. Soc. USSR (English translation).
THE ACTIVITY OF ALUMINUM CHLORIDE PREPARED BY THE RADSIWANOWSKI* METHOD1. THE EFFECT OF AlCl3 PREPARED BY THE RADSIWANOWSKI METHOD UPON THE C6H6 + C2H5Br REACTION
B.N. Dolgov and N.A. Kuchumova J Gen. Chem USSR 1950, pg 469-473 (English translation)
*This is how the English translator spelled it.
Highlights from article:
Investigation of the rate at which "AlCl3-R" (AlCl3-Radsiwanowski) is formed from Al shavings and HCl gas showed that 4 to 5 hours suffice for treating the mixture of benzene and Al shavings, all other quantities remaining the same (adding 2% of Al shavings and a temperature of 10-12 degrees). Any further treatment of the mixture with HCl gas increases the quantity of desalkylation products.
It is stated in the literature that activated aluminum must be used in the preparation of AlCl3 whenever Radsiwanowski AlCl3 is used in a Friedel-Crafts reaction. The best method of activation is calcining the Al shavings at 300 degrees for 30 minutes. We ran a series of tests with Al shavings activated as indicated above. Our results showed that the
preliminary activation has no effect on the preparation of AlCl3 from shavings; in our subsequent research we therefore employed ordinary unactivated shavings.
A series of tests made with varying quantities of Al shavings, from 1% to 10% by weight relative to benzene, showed the optimum quantity to be 2%. Some results from these tests:
Al shavings, g: 1 Ethylbenzene yield: 68% Diethylbenzene yield: 17% Trietheylbenzene yield: 1% Tetraethylbenzene yield: -
Al shavings, g: 2 Ethylbenzene yield: 73% Diethylbenzene yield: 18% Trietheylbenzene yield: 3% Tetraethylbenzene yield: a few drops
Al shavings, g: 4 Ethylbenzene yield: 63% Diethylbenzene yield: 11% Trietheylbenzene yield: 7% Tetraethylbenzene yield: a few drops
Al shavings, g: 5 Ethylbenzene yield: 54% Diethylbenzene yield: 11% Trietheylbenzene yield: 7% Tetraethylbenzene yield: 2%
Al shavings, g: 5 Ethylbenzene yield: 45% Diethylbenzene yield: 12% Trietheylbenzene yield: 8% Tetraethylbenzene yield: 3%
Al shavings, g: 10 Ethylbenzene yield: 40% Diethylbenzene yield: 10% Trietheylbenzene yield: 10% Tetraethylbenzene yield: 3%
Remarks: in all of the tests, 40% of benzene was driven off, based on the amount of benzene placed in reaction.
EXPERIMENTALAll tests were made in a standard apparatus, consisting of a 500 ml RBF fitted with a ground-in reflux condenser and a tube (likewise ground-in) reaching to the bottom of the flask for passing the HCl gas through. The flask was filled with 200 g of pure anhydrous benzene, and 4 g of Al shavings (2%), and a current of anhydrous HCl gas was passed through until the Al shavings were coated with a brown film. Then 100 g of freshly distilled ethyl bromide was added drop by drop, the flask being chilled by ice. After the violent evolution of HBr gas had ended, the mixture was set aside to stand at room temperature for 48 hours and then heated with a reflux condenser to the boiling point of benzene over a water bath for 2 hours. Upon cooling, the reaction products were decomposed with water, saponified, dessicated over CaCl2, and then distilled twice into a herringbone dephlegmator.
Under these conditions, a yield of 72% ethylbenzene was recovered (percentage yield based on ethyl bromide).
2. CONDENSATION OF BENZENE WITH SOME UNSATURATED ALIPHATIC HALOGEN DERIVATIVES AND POLYHALOGEN DERIVATIVESB.N. Dolgov and N.A. Larin J Gen. Chem USSR 1950, pg 475-483 (English translation)
(All reported fractions are after benzene has been driven off)
1) Condensation of 1,2-dichloroethane with benzene. Optimum amount of Al shavings: 2% by weight. Diphenylethane yield rises as the percentage of benzene is increased, tar decreasing correspondingly. For example: 1:1 ratio of benzene to dichloroethane gives 6.4% diphenylethane, 24.1% tar, but 8:1 ratio gives 30.6% diphenylethane, 2.9% tar. Within the 16-80 degree temperature range, increasing temperature increases tar but does not markedly affect diphenylethane yield. Time makes a large difference. Reaction time of 2 hours gives 4% diphenylethane, 1.2% tar. 24 hours gives 25.2% diphenylethane, 7.6% tar. 48 hours gives 26.2% diphenylethane, 14% tar. Some asymmetrical 1,1 diphenylethane was recovered by further fractionation of the fraction of product boiling in the range 260-290. Dibromoethane gave very similar results when used instead of dichloroethane.
2) Condensation of isobutylene bromide with benzene. This condensation was performed under the following conditions: bromide:benzene ratio of 1:4, 2% Al (based on benzene), and reaction at room temperature for 25 hours. After decomposition with water and dessication of the oily layer with CaCl2, the benzene was driven off, and the residue separated into the following fractions:
I (BP 90-160): 4 g
II (BP 167-179): 6.5 g
III (BP 260-293): 28.82
A solid cake of residue remained in the flask. Fraction I is the initial dibromide with traces of the decomposition products and benzene. II proved to be a mixture of isobutyl- and tert-butylbenzenes. Bromination of the product in direct sunlight by the Schramm method enabled us to show that the mixture contained 89% of the tertiary isomer, produced by the isomerization of the isobutylbenzene.
Repeated fractionation of Fraction III yielded an oil with BP 284-288, which proved to be the principal reaction product, 1,1-dimethyl-1,2-diphenylethane, described by Bodroux. The yield of this substance is as much as 45% of the theoretical. It was found that Fraction III also contained minute amounts of 1,2-dimethyl-1,2-diphenylethane.
3) Condensation of 2-methyl-3-chloropropene with benzene (omitted - products similar to those above)
4) Condensation of allyl bromide with benzene. Conditions were similar to those above (1:4 bromide:benzene, 2% Al, 24 hours at room temperature). Fraction I BP 148-152, 1.9 g colorless liquid. Fraction II BP 266-290, 14.8 g of liquid with a lilac fluorescence. Fraction III, BP above 300: 10.6 g thick, dark-brown tar. Repeated fractionation of Fraction I yielded an oil that boiled at 148-150 and proved to be propylbenzene. Repeated fractionation of Fraction II yielded a liquid that boiled at 279-281 and exhibited the beautiful lilac fluorescence of diphenylpropane. We did not examine the product in greater detail.
5) Condensation of 1,2,3-tribromopropane with benzene. The conditions: tribromide:benzene 1:6, 2% Al, room temperature, 20 hours. Some 10% of diphenylpropane was recovered; none of the expected triphenylpropane was found.
6) Condensation of 2-methyl-1,2,3-tribromopropane with benzene. 100 g of benzene and 63 g of bromide (1:6 bromide:benzene) were used, 2% Al, room temperature for 20 hours. The condensate was distilled in a 5 mm vacuum after decomposition with water, drying, and driving off benzene.
Fraction I BP 82-85 5.3 g
Fraction II BP 110-112 15.0 g
11.4 g of thick, dark tar remained in the flask.
Fraction I proved to be unreacted tribromide. Fraction II, after standing overnight, yielded 10 g of crystals, which exhibited a m.p. of 125 degrees after recrystallization from alcohol and caused no depression when mixed with 1,2-dimethyl-1,2-diphenylethane.
7) Condensation of of 2-methyl-1,2-dibromo-3-chloropropane with benzene. The conditions were similar to those in the above reaction. Likewise, a 108-111 degree (at 5 mm) fraction was obtained, which yielded 8 g of crystals after standing for 24 hours; these crystals proved to be 1,2-dimethyl-1,2-diphenylethane.
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Condensation of 1,1,2,2-tetrachloroethane with benzene. 1:6 ratio of chloride to benzene was used, at 20 degrees for 20 hours with 2% Al. After the benzene and unreacted chloride were driven off, 0.5 g of anthracene were eventually recovered. When the reaction was carried out at 70-75 degrees with 6% Al, the condensation proceeds differently, yielding 2.8 g of 1,2-diphenylethane.
9) Condensation of tetrachloroethylene with benzene. The reactants were used in a 1:6 chloride:benzene ratio, at temperatures from 19 to 70 degrees and with up to 10% of Al. No condensation was observed in any experiment.
Summary:
1. AlCl3-R acts like ordinary AlCl3 in promoting cleavage and isomerization in condensation reactions.
2. An increase in the number of halogen atoms in the halogen derivative reduces the latter's ability to enter into condensations.
3. A halogen atom attached to the double bond is practically unreactive in the presence of AlCl3.
3. CONDENSATIONS OF BENZENE WITH ALIPHATIC MONOHALOGEN DERIVATIVESB.N. Dolgov, N.I. Sorokina and A.S. Cherkasov J. Gen. Chem. USSR 1951 563-576 (English translation)
...A Friedel-Crafts reaction of benzene with methyl iodide in the presence of 33% AlCl3 does not take place in the cold or with the application of heat. Only at a pressure of 1.5 atm and a temperature of 80-90 degrees did the authors observe the evolution of HI and the formation of products that had boiling points from 78-135 degrees. We have not found any other references in the literature to this reaction. The reaction takes place with great ease under Radsiwanowski conditions, which testifies to the very high activity of the catalyst compared to ordinary aluminum chloride. The reaction rate is not high at room temperature, but it is vigorous and thoroughgoing at 40 degrees, yielding a mixture of all the methylated benzenes from toluene to hexamethylbenzene inclusive. Increasing the Al percentatge in the reaction mixture promotes greater methylation.
...
The results obtained under various conditions with chloro and bromo alkyls enabled us to set up interesting patterns of behavior. The yields of the monoalkyl benzenes, which are the primary reaction products, drop off as the molecular weight of the radicals increases, products of deeper condensation being formed.
... We see that the use of bromo alkyls always lowered the yields of the alkyl benzenes somewhat...
EXPERIMENTALPreparation of Radsiwanowski AlCl3. 144% of aluminum shavings (based on wt of benzene) was added to a flask containing anhydrous benzene, and anhydrous HCl gas was pass through for 3-4 hours at ordinary temperature. The formation of AlCl3 was accompanied by the evolution of bubbles of gas, the benzene grew dark, and the shavings were covered with a deposit of AlCl3. After standing overnight, the mixture was ready for the addition of other reaction components.
1) Condensation of benzene with methyl iodide (omitted)
2) Condensation of benzene with isopropyl chloride and bromide. As in all the other instances, the benzene was prepared by distilling commercial benzene, the first 10% of the distillate, which contained water, being discarded. The isopropyl chloride was dried above CaCl2 and then distilled. The fraction with BP 36-36.5 degrees was selected. Tests were run for 20 hours at 10-12 degrees with a 1:4 ratio of chloride and benzene. Maximum of isopropylbenzene yield was with 2% Al, being 45% of theoretical. Increasing Al increases polyalkylation, increasing isopropyl chloride increases condensation products/tar. The maximum yield with isopropyl bromide did not exceed 31%. Di- and tri-isopropylebenzenes were also isolated and characterized (omitted).
3) Condensation of benzene with isobutyl chloride and isobutyl bromide. The reaction was effected by boiling the benzene/halide mixture in presence of catalyst. Reaction was difficult to start, yield was poor in all cases, maximum (18%) achieved with isobutyl chloride in 1:4 ratio with 2% Al. Carrying out the reaction at room temperature for 18 hours yielded up to 41% of theoretical butylbenzene yield.
4) Condensation of benzene with isoamyl chloride and bromide. Principle product was tert-amylbenzene, maximum yield 18% (all reactions here were done at boiling temperature for relatively short periods of time).
5) Condensation of benzene with chloroform. More diphenylmethane was formed as more Al was used; more diphenylmethane is also formed with the addition of CuCl. Yield of diphenylmethane could be slightly above 40%. No more than 3-4% triphenylmethane could be recovered under any conditions, and this required tedious extraction from tar.