1-ethyl-1//-pyrrole-2,5-dione

A/-[4-[(4-[ F]Fluorobenzylidene)amino-oxy]butyl]maleimide ([ F]FBABM) was synthesised in two steps, involving the preparation of 4-[ F]fluorobenzaldehyde (see Section 4.3.1.1), in an overall radiochemical yield of 35% in 60 min [267], whereas A/-[2-(4-[ F]fluorobenzamido)ethyl]maleimide ([ F]FBEM) was synthesised in three steps via 4-[ F]fluorobenzoic acid (see Section 4.3.1.1) in an overall radiochemical yield of 12% in 150 min [268]. Finally, based on the successful use of nucleophilic /leferoaromatic ort/io-radiofluorination in the pyridine series (see Section 4.3.2.1), 1-[3-(2-p F]fluoropyridin-3-yloxy)propyl]pyrrole-2,5-dione was prepared in 17-20% non-decay-corrected radiochemical yield in a three-step pathway taking less than 110 min [13,269]. These three reagents have been successfully coupled to peptides and proteins (>80% radiochemical yield in 10 min). 

Finally, ortho aminoesters have been used to produce 7-deazaxanthines. For example ethyl 2-amino-5-phenyl-l//-pyrrole-3-carboxylate is first treated with 2-chloroethyl isocyanate in refluxing toluene. The resulting urea derivative is then allowed to react with l-(2-methoxyphenyl)piperazine and cyclized to the expected pyrrolo[2,3-,7 pyrimidin-2,4(177,377)-dione <2006BMCL150>. 

The facile acid-catalyzed elimination of the elements of water from the carbinols derived from 2-methylindole and 1,3-dicarbonyl compounds, such as ethyl acetoacetate or pentane-2,4-dione, yields the 3-vinylindole derivatives (122) (B-70MI30500). Pyrroles tend to form 2 1 adducts with 1,3-diketones. For example, cyclohexane-1,3-dione produces the bispyrrolyl derivatives (121) (B-77MI30502). 

C6H7N02 1-ethyl-1 H-pyrrole-2,5-dione 128-53-0 453.15 39.402 2 7345 C6H8N20 6-methoxy-3-pyridinamine 6628-77-9 579.00 51.524 2... 

K.63) ///-Pyrrole-2,5-dione, 3-ethyl-4-methyl-, 3-ethyl-2,5-dihydro-4-methylpyrrole-2,5-dione, 2-ethyl-3-methylmaleimide [20189-42-8]... 

Pyrroles. It has been known that pyrroles are very sensitive to photosensitized oxidation and give a complex mixture of products. The pathway of pyrrole reaction is very similar to that of furans. In our study, the photosensitized oxidation of 2-ethylpyrrole gave a 5-ethyl-5-ethoxy-lH-pyrrole-2-one and a lH-pyrrole-2,5-dione in absolute alcohol as shown in Scheme 20. 

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