ChemInform Abstract: Preparation of Novel 2,3,8‐Trisubstituted Pyrido[3,4‐b]pyrazines and Pyrido[2,3‐b]pyrazines.

Antoine, Maud; Czech, Michael P.; Gerlach, Matthias; Guenther, E.; Schuster, Tilmann; Marchand, Pascal

doi:10.1002/chin.201126174

Cited by 1 publication

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“…The deprotometalation-iodination sequence was successfully applied to 8-bromo-2,3-diphenyl pyrido[3,4- b ]pyrazine ( 3a ) [25,26], but failed with 7-bromo-2,3-diphenylpyrido[2,3- b ]pyrazine ( 4a ) due to significant degradation before trapping (Scheme 1). While the position of the iodo group in 3b was evidenced by subsequent reaction, it was studied by advanced NMR experiments in the case of 4b (see Supplementary Materials).…”

Section: Resultsmentioning

confidence: 99%

“…1 H chemical shifts (δ) are given in ppm relative to the solvent residual peak and 13 C chemical shifts are relative to the central peak of the solvent signal [46]. 2,3-Diphenylpyrido[2,3- b ]pyrazine ( 2a ) [6], 8-bromo-2,3-diphenylpyrido[3,4- b ]pyrazine ( 3a ) [25,26] and 7-bromo-2,3-diphenylpyrido[2,3- b ] pyrazine ( 4a ) [6] were prepared as reported previously. The biological activity assays were performed as reported previously [44].…”

Section: Methodsmentioning

confidence: 99%

“…The general procedure 2 using 8-bromo-2,3-diphenylpyrido[3,4- b ]pyrazine ( 3a [25,26], 0.36 g) gave 3b (eluent: CH 2 Cl 2 -petroleum ether 80:20; R f = 0.44) in 67% yield as a red powder. Mp: 186–188 °C.…”

Section: Methodsmentioning

confidence: 99%

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From Quinoxaline, Pyrido[2,3-b]pyrazine and Pyrido[3,4-b]pyrazine to Pyrazino-Fused Carbazoles and Carbolines

et al. 2018

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2,3-Diphenylated quinoxaline, pyrido[2,3-b]pyrazine and 8-bromopyrido[3,4-b]pyrazine were halogenated in deprotometalation-trapping reactions using mixed 2,2,6,6-tetramethyl piperidino-based lithium-zinc combinations in tetrahydrofuran. The 2,3-diphenylated 5-iodo- quinoxaline, 8-iodopyrido[2,3-b]pyrazine and 8-bromo-7-iodopyrido[3,4-b]pyrazine thus obtained were subjected to palladium-catalyzed couplings with arylboronic acids or anilines, and possible subsequent cyclizations to afford the corresponding pyrazino[2,3-a]carbazole, pyrazino[2′,3′:5,6] pyrido[4,3-b]indole and pyrazino[2′,3′:4,5]pyrido[2,3-d]indole, respectively. 8-Iodopyrido[2,3-b] pyrazine was subjected either to a copper-catalyzed C-N bond formation with azoles, or to direct substitution to introduce alkylamino, benzylamino, hydrazine and aryloxy groups at the 8 position. The 8-hydrazino product was converted into aryl hydrazones. Most of the compounds were evaluated for their biological properties (antiproliferative activity in A2058 melanoma cells and disease-relevant kinase inhibition).

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Section: Resultsmentioning

confidence: 99%