Pyrrolo pyridine-2 ,5-diones

The structure of pyrrolo[3,4-. X-Ray crystallographic analysis of reduced derivatives of pyrrolo[3,2-3]pyridines, 31, confirms the m-fusion of the pyridine and pyrrole rings <2003JOC5652>. 

A number of other five-membered ring nitrogen heterocycles have been prepared by cyclative cleavage. The illustrative examples (Fig. 4) depict the synthesis of pyrazolones,12 succinimides and phthalimides,13 pyrrolo[3,4-h] pyridines,14 2-aminoimidazolones,15 imidazo[4,5-fr]pyridin-2-ones,16 and l,2,4-triazoline-3,5-diones.17... 

Preparation of 7-arylmethyl-17/-pyrrolo[3,4-r-]pyridine-l,3-(27/)-diones 128 from 5-bromonicotinamide, arylaceto-nitriles, and lithium diisopropylamide (LDA) occurs via a pyridyne mechanism (Scheme 21). Under similar conditions, 5-chloro-3-pyridinol and arylacetonitriles afford the C-5 substitution products (Equation 49) <1998T3391>. 

We attribute these observations to the rapid self-condensation of the intermediate pyrrolo[3,2-c]pyridine-2,3-dione in analogy with the known sensitivity of 3-oxindole to basic reaction conditions which leads to the rapid formation of indigo. Russell, G. A. Kaupp, G. J. Am. Chem. Soc. 1969,91,3851. 

Methoxycarbonyl methyl-1 //-pyrrolo 3,4-r pyridine-l,3(2//)-dione (47) has been reported to undergo ring expansion to afford methyl 4-hydroxy-1-oxo-l,2-dihydro-2,7-naphthyridine-3-carboxylate (48) (MeONa/MeOH, 100°C ... 

Wang T, Yin Z, Zhang Z et al (2009) Inhibitors of human immunodeficiency virus type 1 (HIV-1) attachment. 5. An evolution from indole to azaindoles leading to the discovery of l-(4-benzoylpiperazin-l-yl)-2-(4,7-dimethoxy-l//-pyrrolo[2,3-c]pyridin-3-yl)ethane-1,2-dione (BMS-488043), a drug candidate that demonstrates antiviral activity in HIV-1-infected subjects. J Med Chem 52 7778-7787... 

Regueiro-Ren A, Xue QM, Ueda Y et al (2009) HIV-1 attachment inhibitors structure-activity relationships leading to the identification of l-(4-henzoylpiperazin-l-yl)-2-(4-fluoro-7-(l//-l,2,3-triazol-l-yl)-l//-pyrrolo[2,3-c]pyridin-3-yl)ethane-l,2-dione. Abstract MEDI-450. 238th ACS national meeting, Washington, DC... 

Cycloaddition and cyclization routes were used to access certain 1,3-diazines. The 4+2 cycloaddition reaction of 4-(N-allyl-N-aryl)amino-l,3-diaza-l,3-butadienes with vinyl-, isopropenyl-, and chloroketene led to pyrimidinone-fused pyrimidinones <97T13841>. Cis-cyclopenta[d]pyrimidines were derived from cis-2-amino-l-cyclopentanecarboxylates by cyclization with KOCN and KSCN <97JHC1211>. 2-Thioxopyrido[3, 2 4,5]thieno[3,2-r/]pyrimidin-4(3//)-ones 19 were prepared by cyclocondensation of 2-carbethoxy-3-amino-4-phenyl-6-substituted-thieno[2,3-/)]pyridines and isothiocyanates <97JHC937>. Thiazolyl-benzimidazoles derived from 2-cyanomethyl-l//-benzimidazole and 2,3-dihydrothiazole-2-(3//)-thiones were cyclized to the corresponding thiazolo[4,5-r/]pyrimidines <97PHA346>. Reductive cyclization of 6-cyanomethyl-5-nitropyrimidines afforded 7-alkyl-5//-pyrrolo[3,2-r/]pyrimidines and 6-amino-7,7-dialkyl-7//-pyrrolo[3,2-rf]pyrimidines <97T391>. 7-Methyl-5-alkyl-2-vinyl-pyrazolo[3,4-r/]pyrimidine-4,6(5//,7//)-diones arose from cyclization and alkylation of... 

It should be noted that a number of SPC polymers which contain other heterocycles have been prepared, motivated by their promising optical or electrical properties. Examples include pyridine (65) [123], pyrrole (66) [124], oxadiazole (67) [125], selenophene (68) [126], benzo[2,l,3]thiadiazole (69) [127], benzo[2,l,3]selenadiazole (70) [126], perylene bisimide (71) [128], 1,4-diketo- pyrrolo[3,4-c]pyrrole-l,4-dione (72 and 73) [127,129], and triphenyleamine (74) [127] as part of the polymer backbone by SPC (Figure 19c). Specifically for metal complexation, porphyrin [130], difluoroboraindacene [131], bipyridine [132], phenanthroHne [113], terpyridine [133, 134], and the like [123] were embedded in the backbone. In this context, an interesting report was submitted by Rehahn et al., in which l,l -ferrocenyl units were incorporated into a PPP (Figure 22.20). Due to a low-energy barrier for rotation around the Cp-Fe-Cp axes (Cp = cyclopentadienyl), the obtained polymer 75 was assumed to take randomly coiled conformations [135]. 

Phenyl chloroformate added to a well-stirred ice-cold soln. of 2,3-dihydro-9-hydroxymethyl-7-methoxy-6-methyl-lH-pyrrolo[l,2-a]indole-5,8-dione (prepn. s. 65) in dry pyridine, and stirred 2 hrs. at room temp. -> 2,3-dihydro-9-hydroxy-methyl -7-methoxy-6-methyl -IH-pyrrolo[1,2-a] indole-5,8- dione phenylcarbonate (Y ca. 100%) dissolved in methylene chloride, acetone-Dry Ici-cooled, NHg-gas introduced for 0.5 hr., and stirred several hrs. at room temp. 2,3-dihydro-9-hydroxymethyl -7-methoxy -6-methyl -IH-pyrrolo [1,2-a] indole -5,8- dione carbamate (Y 74%). G. R. Allen, Jr., J. F. Poletto, and M. J. Weiss, J. Org. Ghem. 30, 2897 (1965). 

Formation of Pyrrolo[2,3-c]pyridinone 2-28 from Pyrrole-2,3-diones 2-24 and Hydroxylamine Hydrochloride. In a 20-mL Schlenk tube, hydroxylamine hydrochloride (1.5 mmol, 104 mg) was added to the pyridine solution (10 mL) of compound 2-24a (180 mg, 0.5 mmol). After the reaction mixture was refluxed for 4 h, the solvent was evaporated in vacuo to give a yellow sohd, which was subjected to Si02 column using petroleum ether, ethyl acetate, and triethylamine (100 20 1) as the eluent to give product 2-28. 

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