A-Methylphenylacetic acids

To a solution of HTI (5.16 g, 13 mmol) in methanol (60 ml) was added phenylpropyne (11.6 g, 10 mmol) and the solution was refluxed for 96 h. The reaction mixture was treated with a saturated solution of sodium bicarbonate, extracted with dichloromethane (3 x 50 ml), dried and concentrated to an oil this was hydrolysed in 2N sodium hydroxide solution to give a-methylphenylacetic acid (9.9 g, 66%) b.p. 262°C. 

Configurational correlation with alanine was achieved recently (33). It was already known that (+ )-a-methylphenylacetic acid (XXIVa) gave (— )-a-phenylethylamine (XXV) (34) by a Curtius degradation with retention of configuration. Oxidative destruction of the aromatic ring in... 

As with indomethacin analogs, the in vivo biological activity of several a-methylphenylacetic acids is invariably associated with the dextro rotatory isomer of the sinister absolute configuration. Thus the stereo-specificity of the a-carbon atom of these anti-inflammatory agents appears to be identical with that of plant growth hormones. 

Ibuprofen [(S+) and (R-) 4-isobutyl-a-methylphenylacetic acid, Brufen, Nurofen, Motrui]... 

Strategy Both Hofmann and Curtius rearrangements convert a carboxylic acid derivative—either an amide (Hofmann) or an acid chloride (Curtius)—into a primary amine with loss of one carbon, RCOY — RNH. Both reactions begin with the same carboxylic acid, which can be identified by replacing the -NH2 group of the amine product by a -COOH group. In the present instance, o-methylphenylacetic acid is needed. 

A solid-phase version of the DMP linker using p-methylphenylacetic acid 33 was reported by Wang [50] it afforded good yields of deprotection of various carboxylic acids within 8h using 280-366nm UV radiation (Scheme 17.16). 

D,L-2-hydroxypalmitic acid 0.30/0.34 J (-)-a-Methoxy-a-trifluoro-methylphenylacetic acid chloride (acid Fluka, Buchs, Switzerland) Plates silica gel (Merck, Germany) coated with phenyl methylvinyl chlor-osilane... 

Rama NH, Turner E, Whalley WB (1981) The Chemistry of Fungi. Part 79. A New Synthesis of 3,5-Dihydroxy-4-methylphenylacetic Acid. J Chem Res (S) 149... 

Perhaps no reagent for enantiomeric resolution is more widely known than a-methoxy-a-trifluoro-methylphenylacetic acid (MTPA), otherwise known as Mosher s reagent [1]. Either the acid or acid... 

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