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P2P syntheses of yonder days

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Ueber den alpha-Phenylacetessigester
Walter Beckh
Chem. Ber. 31, 3160-3164 (1898) (

Sodium ethoxide catalyzed condensation of ethyl acetate with phenylacetonitrile, forming alpha-Phenylacetoacetonitrile, which upon treatment with sulfuric acid is simultaneously hydrolyzed to the acid and decarboxylated to give phenylacetone.
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Ueber Phenacetylmalonsäureester
Hermann Metzner
Ann. 298, 374-378 (1897) (

Phenylacetic acid is chlorinated with PCl5 in chloroform, yielding phenylacetyl chloride in 88% yield. This is then used to acylate sodium diethylmalonate to give the phenylacetylmalonic ester in 75% yield by leaving the mixture undisturbed for a week. Refluxing the phenylacetylmalonic ester in 20% (1.1 g/mL) aqueous hydrochloric acid for a few hours results in double ester hydrolysis and decarboxylation, leaving phenylacetone as the end product.
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Oxydationsprodukte der Benzylketone
A. Popoff
Chem. Ber. 5, 500-502 (1872) (

Alkylation of phenylacetyl chloride with dimethyl zinc under cooling, followed by hydrolysis of the intermediate with dilute hydrochloric acid gave crude P2P, bp 210-217°C. After purification via the crystalline bisulfite adduct, the ketone had bp 214-216°C.
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Zur Geschichte der Phenylessigsäure
B. Radziszewski
Chem. Ber. 3, 198-199 (1870) (

Phenylacetone is prepared by pyrolysis of phenylacetic acid and barium acetate (1:1, w/w). The distillate also contains acetone, toluene and diphenylacetone. The phenylacetone is then isolated by fractional distillation, bp 215°C, d. 1.010 g/mL at 3°C.

Monooxygenase activity of cytochrome c peroxidase
VP Miller, GD DePillis, JC Ferrer, AG Mauk and PR Ortiz de Montellano
J. Biol. Chem. 267, 8936-8942 (1992) (

Recombinant cytochrome c peroxidase (CcP) and a W51A mutant of CcP, in contrast to other classical peroxidases, react with phenylhydrazine to give sigma-bonded phenyl-iron complexes. The conclusion that the heme iron is accessible to substrates is supported by the observation that CcP and W51A CcP oxidize thioanisole to the racemic sulfoxide with quantitative incorporation of oxygen from H2O2. Definitive evidence for an open active site is provided by stereoselective epoxidation by both enzymes of styrene, cis-beta-methylstyrene, and trans-beta- methylstyrene. trans-beta-methylstyrene yields exclusively the trans- epoxide, but styrene yields the epoxide and phenylacetaldehyde, and cis- beta-methylstyrene yields both the cis- and trans-epoxides and 1-phenyl- 2-propanone. The sulfoxide, stereoretentive epoxides, and 1-phenyl-2- propanone are formed by ferryl oxygen transfer mechanisms because their oxygen atom derives from H2O2. In contrast, the oxygen in the trans- epoxide from the cis-olefin derives primarily from molecular oxygen and is probably introduced by a protein cooxidation mechanism. cis-[1,2-2H]- 1-Phenyl-1-propene is oxidized to [1,1-2H]-1-phenyl-2-propanone without a detectable isotope effect on the epoxide:ketone product ratio. The phenyl-iron complex is not formed and substrate oxidation is not observed when the prosthetic group is replaced by delta-meso-ethylheme. CcP thus has a sufficiently open active site to form a phenyl-iron complex, to oxidize thioanisole to the sulfoxide, and to epoxidize styrene and beta-methylstyrene.

Aerogel Catalysts
Thoria: Preparation of Catalyst and Conversion of Organic Acids to Ketones
S. Swann, E. G. Appel, S. S. Kistler
Ind. Eng. Chem. 26(4), 388-391 (1934) (

The conversion of aliphatic Acids to ketones has been studied over thoria aerogel. It has been found that the aerogel catalyst is distinctly superior to thoria hydrogel, thoria prepared from the oxalate, and thoria on pumice for this purpose. The yields of ketones compare favorably with the best reported in the chemical literature.
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Thoria Aerogel Catalyst: Aliphatic Esters to Ketones
S. Swann, E. G. Appel, S. S. Kistler
Ind. Eng. Chem. 26(9), 1014 (1934) (

Alkyl Benzyl Ketones and Hydantoin Derivatives
E.H. Sund and H.R. Henze
Journal of Chemical and Engineering Data 15(1), 200-201 (1970)

Ten alkyl benzyl ketones were synthesized by the interaction of phenylacetyl chloride and the requisite dialkyl cadmium, the synthesis being modeled after a published procedure by Blaise [Compt. Rend. 133, 1218 (1901)].

Preparation of Phenyl-2-Propanone

A mixture of 40 ml. of anhydrous ether and 6.1 grams (0.25 mole) of magnesium was stirred under reflux while 35.5 grams (0.25 mole) of methyl iodide in 140 ml. of anhydrous ether was added over a 3-hour period; stirring under reflux was continued for an additional hour. The reaction mixture was cooled with an ice bath and 22.4 grams (0.134 mole) of powdered anhydrous cadmium chloride was added over a 5- to 10-minute period, warmed to room temperature, and refluxed on a steam cone for 1 hour. Ether was removed by distillation on a steam bath. To theresidue was added 100 ml. of anhydrous benzene and the distillation was continued until about 50 ml. more of distillate was collected. Again 100 ml of anhydrous benzene was added, the flask was cooled in an ice bath, and 30.9 grams (0.2 mole) of phenylacetyl chloride in  75 ml of anhydrous benzene was added with stirring over a period of approximately 10 minutes. The reaction mixture was warmed to room temperature and refluxed with stirring on a steam cone for 1 hour. The flask was again cooled in an ice bath and the reaction mixture decomposed by the addition of a solution of 25 grams of ammonium chloride in 200 ml of cold water. The organic phase was separated, washed, and dried over anhydrous sodium sulfate. The benzene was removed by flash distillation and the ketone distilled under reduced pressure. There was thus obtained 15.5 grams (58%) of 1-phenyl-2-propanone, bp 74-76°C/3 mmHg).

Synthesis of Methyl Ketones from Diethyl Acylmalonates
Howard G. Walker and Charles R. Hauser
J. Am. Chem. Soc. 68, 1386-1388 (1946) (

A convenient method for preparing certain methyl ketones consists in the acylation of the sodium or, preferably, the magnesium-ethoxy derivative of diethyl malonate with the appropriate acid chloride, followed by hydrolysis and decarboxylation of the two ester groups of the resulting diethyl acylmalonate in the presence of acid, thus:

In the present investigation, satisfactory yields [was obtained of] phenylacetone1. We have chosen the magnesium ethoxy derivative of diethyl malonate2 rather than the sodium derivative because we believe the former is prepared more conveniently. Although the acid chloride does not appear to react appreciably with the excess alcohol2 used in the preparation of the magnesium-ethoxy derivative, we have employed a 10% excess of the latter in order to minimize this possible side reaction. The crude diethyl acylmalonates were hydrolyzed and decarboxylated in the presence of aqueous acetic and sulfuric acids according to the method previously employed for the ketonic cleavage of certain beta-keto esters3. The present method appears to be one of the best for the preparation of certain higher aliphatic or aliphatic-aromatic4 methyl ketones [...].


Diethyl acylmalonates were prepared by a modification of the procedure of Lund2,5

In a 500-ml three-necked flask equipped with a mercury-sealed stirrer, dropping funnel, and reflux condenser protected by a drying tube, was placed 5.35 g. (0.22 mole) of magnesium. Five ml of absolute ethanol and 0.5 ml of carbon tetrachloride were added. The reaction, which started almost immediately, was allowed to proceed for a few minutes and 75 ml of absolute ether was then added cautiously. The resulting mixture was placed on the steam bath and a solution of 35.2g (0.22 mole) of diethyl malonate, 20 ml of absolute ethanol and 25 ml of absolute ether was added at such a rate that rapid refluxing was maintained, heat being applied when necessary. The mixture was refluxed for three hours, or until the magnesium had dissolved. To the clear solution was added with vigorous stirring6 an etheral solution of 30.8g (0.20 mole) phenylacetyl chloride and the mixture refluxed for one-half hour. The reaction mixture was cooled and acidified with dilute sulfuric acid. The ether phase, with which an ether extract of the aqueous phase was combined, was washed with water and the solvent distilled.

To the crude diethyl phenylacetylmalonate was added a solution of 60 ml of glacial acetic acid, 7.5 ml of concentrated sulfuric acid and 40 ml of water, and the mixture refluxed for four or five hours until the decarboxylation was complete. The reaction mixture was chilled in an ice-bath, made alkaline with 20% sodium hydroxide solution, and extracted with several portions of ether. The combined ethereal extracts were washed with water, dried with sodium sulfate followed by Drierite, and the solvent distilled. The residue containing the ketone was distilled in vacuo to give Phenyl-2-Propanone in 71% yield (bp 97-98.5°C/13 mmHg, 214-215°C/760mmHg).

[1] Metzner prepared phenylacetone by this method, but no yield was reported: Ann. Chem. 298, 378 (1897) (
[2] Lund, Chem. Ber. 67B, 935 (1934)
[3] Hudson and Hauser, J. Am. Chem. Soc. 63, 3163 (1941)
[4] We believe that the malonic ester method is more convenient for phenylacetone than those described in Org. Synth. Coll. Vol. II, 389, 391 (1943) (
[5] The present procedure is similar to that of Breslow, Baumgarten, and Hauser [J. Am. Chem. Soc. 66, 1286 (1944)] for the preparation of ethyl tert-butyl acylmalonates.
[6] In certain cases a viscous mixture was formed and unless it was stirred vigorously, lower yields were obtained.


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