Propionyl chloride Propiophenone

An improved yield is obtained by the following process. Add a mixture of 75 g. (70-5 ml.) of propionyl chloride and 90 g. (103 ml.) of sodium-dried A.R. benzene to a vigorously stirred suspension of 75 g. of finely-powdered anhydrous aluminium chloride in 100 ml, of dry carbon disulphide, Then introduce more of the aluminium chloride (about 15 g.) until no further evolution of hydrogen chloride occurs. The yield of propiophenone, b.p. 123°/25 mm., is about 90 g. 

Propiophenone. Prepare a solution of diphenyl-cadmium in 110 ml. of dry benzene using 4 9 g. of magnesium, 32 4 g. of bromobenzene and 19 5 g. of anhydrous cadmium chloride. Cool the solution to 10°, and add during 3 minutes a solution of 14 -8 g. of propionyl chloride (b.p. 78-79°) in 30 ml. of dry benzene use external coohng with an ice bath to prevent the temperature from rising above 40°. Stir the mixture for 2 hours at 25-35°. Work up the product as detailed above except that 6 per cent, sodium carbonate solution should replace the saturated sodium bicarbonate solution. The yield of propiophenone, b.p. 100-102°/16 mm., is 17 6 g. 

Propiophenone. Propiophenone [93-55-0] (ethyl phenyl ketone) is a colorless Hquid with a flowery odor. It can be prepared by the Friedel-Crafts reaction of benzene and propionyl chloride in the presence of aluminum chloride (346), or by the catalytic reaction of benzoic acid and propionic acid in the presence of water (347). Propiophenone is commercially available (348), and is sold in Japan at 2700 Y/kg (349). It is used in the production of ephedrine, as a fragrance enhancer, and as a polymerization sensitizer. 

An intEiesting variant on the Wilgerodt reaction offers a simple three-step procedure that avoids the wastage involved in the schemes above, which require the incorporation of an extra carbon atom that must later be eliminated. The sequence starts with the acylation of isobutylbenzene (49-1) with propionyl chloride to give propiophenone (49-2). Reaction of that with thallium 111 nitrate and methyl ortho-formate in methanol leads in high yield to the methyl ester (49-3) of ibuprofen [50]. This would be the method of choice for preparing the dmg but for two unfortunate facts the extreme toxicity of thallium and the very high sensitivity of analytical methods for the detection of metals. It proved to be virtually impossible, in practice, to produce samples that showed zero residues of thallium. 

Propionic acid, /J-(chloroformyl)-, METHYL ESTER, 25, 19 Propionic acid, /J,/S -methyliminobis, DIETHYL ESTER, 20, 35 Propionic anhydride, 21, 14 Propionitrile, /3-amino-, 27, 3 Propionitrile, 6-ETHOXY-, 23, 33 Propionitrile, 6,6 -iminodi-, 27, 3 Propionyl chloride, 24, 30 Propiophenone, 6-diethylamino-, 23, 31... 

I. Propiophenone may be prepared in 70-80 per cent yields from benzene and propionyl chloride or propionic anhydride, in the presence of aluminum chloride. 

Previtamin D3, 58-59 Progesterone, 65 Propane-1,3-diol, 222 Propargyl bromide, 28 Propargyl chlorides, 23 Propanol-2, 48 2-Propenyllithium, 302 Propionyl chloride, 49 Propylene oxide, 107 Propiophenone, 59 Propyl methyl ketone, 294 n-Propyl nitrate, 185 Prop-l-yn-3-ols, 99... 

Propionic anhydride, 21, 14 Propionitrile, /3-ethoxy-, 23, 33 Propionyl chloride, 24, 30 Propiophenone, /3-diethy lamino-, 23,... 

Preparation by Friedel-Crafts acylation of o-hydroxy-propiophenone with propionyl chloride in the presence of aluminium chloride in refluxing carbon disulfide for 2 h (94%) [8365],... 

Prop-2-enyl trifluoromethanesulfonate, 1457 Propionyl hypobromite, 1150 Propionyl nitrite, 1181 Propiophenone, 3145 f Propyl acetate, 1971 f Propyl bromide, see 1-Bromopropane, 1237 f Propyl chloride, see 1-Chloropropane, 1239 Propylcopper(I), 1247... 

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