The Hive > Chemistry Discourse
AlCl3 and Md compounds
Kinetic:
Antoncho, you don't know how much this means to me. Thankyou so much! Your translation is infinitely better than the '??!.????!.' Babelfish churned out :P . Thanks also to lugh for finding the original article for me (recently requested in Wanted References). This will be tested out for benzodioxole/propionyl chloride within a few weeks, hopefully giving a decent yield of 3,4-methylenedioxypropiophenone :) .
Antoncho:
Hey, bees, look what i found, mapping the faraway honeyfields of Uspatland :) :) :)
Looks like all we need to make aceto- and propiophenones from all sorts of stuff is:
a) Tosic acid (make some yourself from toluene and H2SO4)
b) Dean-Stark trap
Patent US5041616
"I have discovered that aryl ketones may be obtained by heating a carboxylic acid with certain aromatic compounds in the presence of (1) a volatile, organic compound which forms an azeotrope, i.e., a constant boiling mixture, with water and (2) a catalytic amount of an organic sulfonic acid, whereby the water of reaction is removed as an azeotrope from the reaction mixture. "
"The carboxylic acid employed is not critical and may be selected from a wide variety of unsubstituted and substituted, aliphatic, cycloaliphatic and aromatic carboxylic acids containing from 2 to 20 carbon atoms."
"...Phenols and benzenediols, as well as ethers and esters thereof, may be acylated using methanesulfonic and toluenesulfonic acids. In the case of less reactive aromatic compounds such as alkylaromatic compounds, e.g., toluene and xylene, a more acidic sulfonic acid such as a perhaloalkylsulfonic acid, e.g., trifluoromethanesulfonic acid normally is required to achieve satisfactory reaction rates."
EXAMPLE 3
Hydroquinone (11.0 g, 0.1 mole), octanoic acid (30.2 g, 0.21 mole), heptane (110 mL), and methanesulfonic acid (10 mL, 0.14 mole) were heated at reflux (98.degree. C.) for 5 hours in a 300 mL flask equipped with a Dean-Stark trap. During this time, 3 mL of water was collected. The sulfonic acid layer was separated, and the heptane layer was washed once with 50 mL of water and twice with 50 mL portions of saturated, aqueous sodium bicarbonate solution. The mixture was filtered to remove 5 g of product, octanoylhydroquinone octanoate ester, while evaporation of the organic layer gave 17.3 g. The total yield of octanoylhydroquinone was 22.3 g, 94% of theory.
Now, don't you think that 'CiHKAL' is a nice name for a book? ;) ;) ;)
Antoncho
P.S. BTW, this rxn is also great since it allows one to watch its progress by measuring the amt of water - something of great importance when adjusting conditions to different substrates and reagents.
Aurelius:
US Patent 5041616
Preparation of Aryl Ketones
Example 1:
A mixture of p-toluic acid (22.2g, 0.163mol), p-xylene (100ml), and trifluromethanesulfonic acid (5ml, 0.056mol) was heated at reflux for 21 hours in a 300ml flask equipped with a Dean-Stark trap, after which time 3ml of water had been collected in the trap. The progress was measured with GC as well as by the amount of water collected. After 6 hours, 22% of the starting material had been converted to 2,5,4’-trimethylbenzophenone. The mixture was extracted with water, with 5% sodium hydroxide and again with water. Evaporation of the organic layer gave 24g (0.11mol) of 2,5,4’-trimethylbenzophenone, 66% of theory.
Example1; modified:
The procedure in Example 1 was repeated without a Dean-Stark trap. After 4 hours of reflux, only about 6% of the starting material had been converted to product. The amount of product was not increased significantly after refluxing an additional 6 hours.
Example 2:
Benzoic acid (20g, 0.16mol), p-xylene (100ml), and trifluoromethanesulfonic acid (5ml) were heated at reflux in a 300ml flask equipped with a Dean-Stark trap. After 16 hours, the mixture was extracted with 100ml of 6% sodium hydroxide, washed with 100ml of water, dried over Mg sulfate and evaporated to give 15.4g (0.073mol) of 2,5-dimethylbenzophenone. The aqueous sodium hydroxide extract was acidified to give 8.1g (0.066mol) of unreacted benzoic acid.
Example 3:
Hydroquinone (11.0 g, 0.1 mole), octanoic acid (30.2 g, 0.21 mole), heptane (110 mL), and methanesulfonic acid (10 mL, 0.14 mole) were heated at reflux (98.degree. C.) for 5 hours in a 300 mL flask equipped with a Dean-Stark trap. During this time, 3 mL of water was collected. The sulfonic acid layer was separated, and the heptane layer was washed once with 50 mL of water and twice with 50 mL portions of saturated, aqueous sodium bicarbonate solution. The mixture was filtered to remove 5 g of product, octanoylhydroquinone octanoate ester, while evaporation of the organic layer gave 17.3 g. The total yield of octanoylhydroquinone was 22.3 g, 94% of theory.
Kinetic:
Does anyone have experience working with SnCl4? The procedure above doesn't mention any special precautions need to be taken, and I was wondering how stable it is to hydrolysis, compared to, say, AlCl3 or SiCl4. Is a syringe necessary, as in https://www.thevespiary.org/rhodium/Rhodium/chemistry/iap.html ?: 10g (84.6 mmol) of indane was dissolved in 100ml dichloromethane and cooled to 0°C on an ice bath. With vigorous stirring, 15ml (127 mmol) SnCl4 was added all at once via syringe, folllowed by the dropwise addition of 9.72g (7.65ml, 84.6 mmol) dichloromethyl methyl ether over a 10-minute period.
--- End quote ---
Or will it happily sit in a dry dropping funnel exposed to the atmosphere for 30 minutes while it's added to the reaction mixture? I really hope it isn't as hard to work with as SiCl4 would be in a clandestine setting!
Rhodium:
SnCl4 will smoke heavily in air, forming SnO2/HCl. It is similar to TiCl4 in that respect.
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