2- Pyrrolecarboxylic acid

W-Pyrrole-3-carboxylic acid 3-Pyrrolecarboxylic acid C5H5NO3 931-03-3 111.100 rrd (lig) 161.6 ... 

TABLE 1.59. 5-ARYL-2-(DIALKYLAMINOCARBONYL)-4-(DIMETHYLAMINO)-3-PYRROLECARBOXYLIC ACID ETHYE ESTERS EROM 2-ARYE-5-(DIAEKYEAMINO)-4-OXAZOEEACETIC ACID ETHYE ESTERS UNDER VIESMEIER-HAACK CONDITIONS"... 

Deasy C (1961) Occurrence of 2-pyrrolecarboxylic acid in hide hydrolyzates and its bearing on the determination of hydroxyproline. J Am Leather Chem Assoc 56,... 

There are no reports in the literature of the formation of pyrrole derivatives by the oxidative degradation of the o-quinone rings of the simple aminochromes. However, several pyrrolecarboxylic acids have been obtained on oxidation of the melanins, which are considered by some authors to contain aminochrome units in the polymer (cf. ref. 168), (see Section V, A), and pyrrole-2,3,5-tricarboxylic acid has been... 

P-Aminopyridones form diazo anhydrides (e.g. 729) (cf aminophenols) which on irradiation give pyrrolecarboxylic acids (731) via (730). 

A noteworthy application of pyrrole photo-oxygenation has been recently reported by Wasserman (Sch. 42) starting from the tert-butyl ester of 3-methoxy-2-pyrrolecarboxylic acid 73 [70]. Oxygenation of this compound leads to the intermediate hydroperoxide 74 which undergoes... 

Esters of a-benzindolecarboxylic acids are cleaved in the same manner as the corresponding esters of pyrrolecarboxylic acids.43 ... 

Particular attention has been paid to the oxidation of pyrrolecarboxylic acids, since it is related to the studies about the oxidative degradation of several natural pigments,67 which give mainly pyrrole acids among the identifiable products. Thus, the stability of the acids toward the oxidizing agents, and also hydrogen peroxide, has been tested.65... 

Fluoropyrroles. Pyrrolecarboxylic acids undergo fluorodecarboxylation on exposure to this reagent. 

Pyrrolecarboxylic acids are the final products of oxidative degradation of eumelanins. The origin, reaction conditions, as well as the isolation and identification techniques used are the factors responsible for the different ratios of di-, tri-, and tetracarboxylic acids formed (7). Thus, untreated sepiomelanin and a number of synthetic melanins oxidized via KMNO4 showed the following trend in the relative ratios of pyrrolecarboxylic acids 2,3,5 2,3 = 2,3,4,5. The same samples after decarboxylation at 200°C followed the sequence 2,3,5 > 2,3 > 2,5 2,4 = 2,3,4,5. The decrease in 2,3,5 triacids and the increase in 2,3 diacids are attributed to the loss of carboxyl groups owing to the thermal treatment (7). Resistance to further oxidative degradation u der specific experimental conditions may substantially influence the ratio of the individual pyrrolecarboxylic acids formed (315). 

W-Acetylneuraminic acid has an empirical composition of CnHuNOg, and [ ] —32.0° (in water) m. p. 183-185°. On heating with methanolic hydrogen chloride, it is readily converted to monomethoxyneuraminic acid with concomitant loss of its reducing properties. Boiling the compound with alkgli yields 2-pyrrolecarboxylic acid. ... 

Since glutamine, glutamic acid, 5-pyrrolidine-2-carboxylic acid, proline, hydroxyproline, and V-acetyl-n-glucosamine all failed to form 2-pyrrolecarboxylic acid under these conditions of alkaline degradation, it was concluded that the labile 4-hydroxypyrroline (I, II) is the actual precursor. 

Corbella et a . used Iiypophosphorous acid in combination with hydrogen iodide for reduction of 2-pyrrolecarboxylic acid (I) to 3,4-dehydroproline (2). 

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