Formylphenylacetic acid

Dehydration of o-acetylphenylacetic acid phenylhydrazone gave diazepine (53, R = CH3, R = C6H6) and l-methyl-2-(phenylamino)-3(2//)isoquinoline.43 Pyrolytic dehydration gave 53 as the major product while sulfuric acid gave the quinoline as the major product. The azine of o-acetylphenylacetic acid on pyrolysis gave the diazepine (53, R = CH3, R = H) which was also obtained by pyrolytic elimination of carbamic acid from o-acetylphenylacetic acid semicarbazone.43 Similar pyrolysis of o-formylphenylacetic acid semicarbazone gave 53 (R = R = H). These last two diazepines are assigned structure 53... 

One of the most efficient enzymatic systems that generates triplet state acetone is the horse radish peroxidase(HRP)-catalyzed oxygenation of isobutyraldehyde (Eq. 79). Related enzymatic processes include the autoxidation of linear carbox-aldehydes, malonaldehyde, a-formylphenylacetic acid, indole-3-acetal-dehyde, indole-3-pyruvic acid, ° and indole-3-acetaldehyde. Consequently, there is no question about the existence of enzymatically generated electronic excitation in the cell however, what do these excited states do in the biological system ... 

Other syntheses of tropic acid have been accomplished by Spiegel, Miiller, Wislicenus and Bilhiiber, Chambon and Natarajan and Swamina. ( > Of these, the most interesting is the reduction of ethyl formylphenylacetate (VIII) CHO. CHPh. COOC Hj in moist ethereal solution by aluminium amalgam to ethyl tropate, from which the acid (IX) HO. CHj. CHPh. COOH, is obtainable by hydrolysis with baryta. 

III was acidic, decomposing sodium carbonate in the cold, and giving a red colour with ferric chloride, a reaction regarded by W. Wislicenus as characteristic of enolic forms (containing OH groups) in many cases the colour is violet-blue. IV, shown to have the same mol. wt. as III, was neutral and did not react with sodium carbonate it dissolved only slowly in potassium hydroxide solution, and on acidifying III was precipitated. Ill dissolved in hot dilute alcohol IV crystallised on cooling. Formylphenylacetic ester was shown by W. Wislicenus to exist in two forms ... 

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