80985-55-3Relevant academic research and scientific papers
Potentially tautomeric 1,2,3,4-tetrahydro-1,4-dioxo-5H-pyridazino[4,5-b]indole
Guven,Jones
, p. 11145 - 11154 (1993)
The tautomeric 1,4-dioxygenated pyridazinoindole 1 exists in aqueous solution as a mixture of all four tautomeric forms 1a - 1d. The predominant tautomeric form is the 4-hydroxy-1-oxo compound 1b. The relative abundance of the four forms 1a ? 1b ? 1c ? 1d at equilibrium is 104.93:108.03:103.61:1
Electrochemical Dearomative Dicarboxylation of Heterocycles with Highly Negative Reduction Potentials
Hayashi, Hiroki,Kanna, Wataru,Maeda, Satoshi,Mita, Tsuyoshi,Takano, Hideaki,You, Yong
supporting information, p. 3685 - 3695 (2022/03/08)
The dearomative dicarboxylation of stable heteroaromatics using CO2is highly challenging but represents a very powerful method for producing synthetically useful dicarboxylic acids, which can potentially be employed as intermediates of biologically active molecules such as natural products and drug leads. However, these types of transformations are still underdeveloped, and concise methodologies with high efficiency (e.g., high yield and high selectivity for dicarboxylations) have not been reported. We herein describe a new electrochemical protocol using the CO2radical anion (E1/2of CO2= -2.2 V in DMF and -2.3 V in CH3CN vs SCE) that produces unprecedented trans-oriented 2,3-dicarboxylic acids from N-Ac-, Boc-, and Ph-protected indoles that exhibit highly negative reduction potentials (-2.50 to -2.94 V). On the basis of the calculated reduction potentials, N-protected indoles with reduction potentials up to -3 V smoothly undergo the desired dicarboxylation. Other heteroaromatics, including benzofuran, benzothiophene, electron-deficient furans, thiophenes, 1,3-diphenylisobenzofuran, and N-Boc-pyrazole, also exhibit reduction potentials more positive than -3 V and served as effective substrates for such dicarboxylations. The dicarboxylated products thus obtained can be derivatized into useful synthetic intermediates for biologically active compounds in few steps. We also show how the dearomative monocarboxylation can be achieved selectively by choice of the electrolyte, solvent, and protic additive; this strategy was then applied to the synthesis of an octahydroindole-2-carboxylic acid (Oic) derivative, which is a useful proline analogue.
Synthesis and chemiluminescent activity of pyridazino[4,5-b]indole-1,4(2H,3H)-diones
Kurumi, Masateru,Sasaki, Kenji,Takata, Hiroko,Nakayama, Taiji
, p. 2809 - 2819 (2007/10/03)
Substituted and non-substituted anilines were transformed to the corresponding triazole derivatives, which were converted to dimethyl indole-2,3-dicarboxylates by photocyclization. The reaction of diester with hydrazine hydrate gave 1,2,3,4-tetrahydro-5H-
