A-Phenylbutyric acid chloride

IB.2 grams of a-phenylbutyric acid chloride are dissolved in 25 ml of toluene. To this solution, there is slowly added a solution of 16.1 grams of diethylaminoethoxyethanol in 25 ml of toluene, the reaction mixture thereby becoming hot. It is then heated for B hr under reflux. The reaction mixture, after cooling, is carefully poured onto 75 grams of ice and made alkaline with dilute ammonia. After thorough shaking of the solution, the toluene layer is removed and washed until neutral with water. The toluene solution is treated with carbon and dried over sodium sulfate. The toluene is distilled off from the filtered solution. 

A very interesting approach to optically active sulphoxides, based on a kinetic resolution in a Pummerer-type reaction with optically active a-phenylbutyric acid chloride 269 in the presence of /V,A -dimethyIaniline, was reported by Juge and Kagan332 (equation 149). In contrast to the asymmetric reductions discussed above, this procedure afforded the recovered sulphoxides in optical yields up to 70%. Chiral a, /1-unsaturated sulphoxides 270 were prepared via a kinetic resolution elaborated by Marchese and coworkers333. They found that elimination of HX from racemic /i-halogenosulphoxides 271 in the presence of chiral tertiary amines takes place in an asymmetric way leading to both sulphoxides 270 and 271, which are optically active (optical yields up to 20%) with opposite configurations at sulphur (equation 150). 

Recently, Juge and Kagan (68) reported that a more efficient kinetic resolution of racemic sulfoxides takes place in the Pummerer-type reaction with optically active a-phenylbutyric acid chloride 38 in the presence of N,A-dimethylaniline. In contrast to the asym-... 

Optically active amines. Esterification of an oxime, for example 2-hydroximino-1-phenylpropane (1), with a chiral carboxylic acid chloride, S-( + )-2-phenylbutyric acid chloride (2), gives an oximoester (3), which on reduction with diborane gives a mixture of optically active amines (4a, 4b) in which the S-enantiomcr (4a) predominates slightly. (The optical yield is about 6%.)... 

Acid chlorides can be cyclized by PPE.12 In the example formulated the mixture of the acid chloride from 4.65 g. of a-phenylbutyric acid with 23 g. of freshly pre-... 

The Y-phenylbutyric acid is cyclised to a-tetralone by converting it into the acid chloride with thionyl chloride or phosphorus pentachloride and then an intramolecular Friedel and Crafts reaction is carried out ... 

With Thionyl Chloride. A good procedure for the cyclization of 7-phenylbutyric acid to tetralone-1 is described in Organic Syntheses,79 The acid is treated with thionyl chloride, the excess of which is removed under reduced pressure carbon disulfide is added, then aluminum chloride, and the mixture is heated for a short period. This description may be considered a general procedure, although the reaction time and temperature may have to be altered and mechanical stirring may be required. 

Amalgams. In effecling Clemmenscn-Marlin rcdiiclion of (l-benzoylpropionic acid to Y-phenylbutyric acid. Martin shook a mixture of 120 g, of mossy zinc, 12 g. of mercuric chloride, 20(1 ml. of WHter, and 5-6 ml. of concU. hydrochloric... 

Phenylazide, 31,16 Phenylazoacetoacetic acid, 32, 85 Phenyl benzoate, 32, 103 a-PHENYL-7-(4-BR0M0PHENYL)ACET0-ACETONITRILE, 35, 32 hlWS-l-PHENYL-l,3-BUTADIENE, 30, 75 7-Phenylbutyric acid, 33, 91 35, 96 7-Phenylbutyryl chloride, 35, 96 a-PHENYL-a-CARBETHOXYGLUTARONI-TRILE, 30, 80, 82 a-Phenylcinnamonitrile, 32, 63 2-Phenylcycloheptanone, 35, 91 Phenyldiazomethane, 35, 94 Phenyldichlorophosphine, 31, 88... 

Typical procedure. 4,4 -Bis[(3-carbomethoxy)propyl]benzophenone 1268 [952] By a standard esterification procedure, 4-phenylbutyric acid was converted to its methyl ester 1267 in 92% yield. To carbon disulfide (100 mL) was added 50 g of this ester, followed by oxalyl chloride (17.4 g). The solution was cooled to 0 °C and anhydrous aluminum chloride (74 g) was slowly added. The mixture was then stirred at 25 °C for 3.5 h. The solvent was subsequently decanted from the heavy brown syrup that separated, and the syrup was stirred with 2 kg of ice. This mixture was extracted with diethyl ether, and the ethereal layer was washed with water, dried, and concentrated to a thick orange liquid, which was distilled to give 38.8 g (73%) of faintly yellow liquid bp 280-285 °C/2 mmHg. 

The 4(4 -n.butyl phenylazo)phenylbutyric acid described earlier is easily converted to an acid chloride and thence to a wide variety of activated or activatable species, including acylazide, amine (by acyl azide rearrangement), diazoketone (with diazomethane), iodide (by Huns-diecker reaction) and alkene (by treatment with Wilkinson s catalyst). Alkenes are easily converted to silanes, so that this offers a direct route to a derivative of the type used by Sagiv in the work mentioned earlier. 

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