Pyrrole-2-carboxamide

H-Pyrrole-2-carboxamide, JV,JV-dimethyl-AG 4, 34 (76JOC3591, 77T1337), 194 (76JOC3591)... 

Pyrrole-2-carboxamide, N,N-dimethyl-conformation, 4, 194 Pyrrole-3-carboxamide, N,N-dimethyl-conformation, 4, 194 Pyrrolecarboxamides synthesis, 4, 242 Pyrrole-2-carboxamides synthesis, 4, 148, 360 Pyrrolecarboxylhydrazides Curtius degradation, 4, 362 Pyrrole-2-carboxylic acid, l-benzyl-3-hydroxy-ethyl ester... 

CN A-[5-[[(3-amino-3-iminopropyl)amino]carbonyl]-l-methyl-l//-pyrrol-3-yl]-4-[[[4-(rormylamino)-methyl-l//-pyrrol-2-yl]carbonyl]amino]-l-methyl-lf/-pyrrole-2-carboxamide... 

Animal glue HMDS Pyrrole 2 carboxamide, diketodipyrrole, pyrrole[1,2 a]piperazine 3,6 dione 28... 

H-Pyrrole-2-carboxamide, N.N-dimethyl-AGrot, 4, 34 <76JOC3591, 77X1337), 194 <76JOC3591>... 

Chemical Name N"-(2-Amidinoethyl)-4-formamido-l,l, l"-trimethyl-N,4 N,4"-ter-(pyrrole-2-carboxamide) hydrochloride... 

Preparation of A-(5- [(5- [(5- [(2- [amino(imino)methyl]amino ethyl)amino]-carbonyl -l-methyl-lH-pyrrol-3-yl)amino]carbonyl -l-methyl-lH-pyrrol-3-yl)amino]carbonyl -l-methyl-lH-pyrrol-3-yl)-4-[(2-bromoacryloyl)amino]-carbonyl-l-methyl-lH-pyrrole-2-carboxamide hydrochloride... 

The racemic midpacamide (IS), possessing both pyrrole-2-carboxamide and N-methylated hydantoin moieties, has been isolated from an unidentified marine sponge collected in the Marshall Islands [35] and, subsequently, from the sponge Agelas mauritiana [36]. Two different total syntheses have been reported for this compound [37,38]. 

Mild thermal rearrangement of the carbonyl azides 408 in 1-methylpyrrole gave l-methyl-A -(2-thiophene)-, l-methyl-iV-(2-selenophene)- and l-methyl-iV-(2-furano)-l//-pyrrole-2-carboxamides 409 in good yields, presumably involving the intermediacy of the corresponding isocyanate (Equation 97) <2000ARK58>. In this case, the successful outcome of such thermal reactions is ascribable to the pronounced acidic property of the pyrrole 2-proton. 

Nonalkylated 3,4-dehydroprolines 914 were obtained in 76-81% yields by diastereoselective protonation of an enolate resulting from Birch reduction of the A -BOC-pyrrole-2-carboxamide 913 (Equation 223) <1999T12309>. The reaction was quenched by addition of solid ammonium chloride after a reaction time of 1 h. The results using lithium and sodium are similar but the reaction with potassium failed. Remarkably, asymmetric protonation is more selective (de 88-90%) than methylation (de 50%). The selectivity decreases with increasing temperature (de 82% at —30°C). The diastereoselectivity of the reaction was detected by HPLC. 

Robertson and Witkop used phosphonium iodide in fuming hydiiodic acid to reduce pyrrole-2-carboxamide (1) to au easily separated mixture of 3,4-dehydro-prolinamide (2) and 3,4-dehydroproline (3). 

The regioselectivity (N- vs. C-3) of the intramolecular cyclization of 2-(proline-substituted)pyrroles has been examined <05TL249>. The regiochemical outcome was dependent on electronic factors and pH. This chemistry was utilized in the preparation of the rings embodied in pyrrole-2-carboxamide marine natural products such as dibromophakeUin. 

There are examples of direct introduction of carboxamide substituents by electrophilic substitution. For example, pyrrole-2-carboxamide can be prepared in good yield using chloro-sulfonylisocyanate as an electrophile (Scheme 111) <80CJC409>. 

Ring contractions are sometimes observed when halopyridines or halopyrimi-dines are treated with potassium amide. 2-Bromo-3-pyridinol (XII-635, R = H) and an excess of potassium amide in liquid ammonia give pyrrole-2-carboxamide (XI-636, R = H). 2,6-Dlbromo-3-pyridinol (XII-635, R = Br) forms 5-bromo-pyrrole-2-carboxamide (XII-636, R = Br). ... 

The pyrrole-imidazole alkaloids, mainly isolated from various species of the Agelasidae, Axinellidae, Dyctionellidae, and Hymeniacidonidae sponge famihes, contain characteristic pyrrole-2-carboxamide and 2-aminoimidazoline moieties or derivatives thereof. Their architectural complexity ranges from simple, achiral, monomeric oroidin to the 16-stereocenter-containing tetrameric stylissadines A and B (Fig. 9.4). Because many reviews have appeared describing these alkaloids [52-56], we provide only a short discussion of some biosynthetically and synthetically pertinent information. 

A variety of pyrrolo[l,2-a]quinoxaline derivatives 406 were synthesized in good to excellent yields when pyrrole-2-carboxamides 405 were used instead of a-amino acid derivatives in reactions with 1-fluoro- (383) and chloro- (404) -2-nitrobenzenes under a mild transition metal-free process (Scheme 2.73) (Huang et al. 2011). 

When indole-2-carboxamides were used instead pyrrole-2-carboxamides it was possible, by analogy, to synthesize indolo[l,2-a]quinoxalines in 82-92 % yields (Huang et al. 2011). 

Rotas G, Kimbaris A, Varvounis G (2004) Synthesis of 5-alkyl(oraryl)pyrrolo[l,2-a]quinoxalin-4 (5H)-ones by denitrocyclisation of lV-alkyl(or aryl)-l-(2-nitrophenyl)-l//-pyrrole-2-carboxamides. Evidence of a Smiles rearrangement. Tetrahedron 60(48) 10825-10832. doi 10.1016/j.tet.2004.09.048... 

A Pt-catalyzed intramolecular aryl C(sp )-H functionalization was developed by Seller and coworkers with pyrrole-2-carboxamide alkyne 141 in the presence of H2PtClg 6H2O, which was applied to construct poly-Af-heterocycles (Scheme 12.62) [66]. Pyrrolo[3,2-c]azepin-4-one derivatives 142 were obtained in moderate to good yields. Interestingly, this 7-endo-dig cyclization process involved a concomitant rearrangement of the amidocarbonyl group from the 2-to the 3-position of the pyrrole ring. 

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