Aromatic and heteroaromatic annelation studies on 3-[bis(methylthio)methylene]-1-methyloxindole: synthesis of carbazoles and an efficient route to pyrido[2,3- b]indoles

• Published in: Tetrahedron Vol. 57; no. 4; pp. 781 - 790
• Main Authors: Suresh, J.R, Syam Kumar, U.K, Ila, H, Junjappa, H
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-01-2001
• Subjects: aromatic annelation; carbazoles; pyrido[2,3- b]-indoles; α-oxoketene dithioacetals; carbazoles; α-oxoketene dithioacetals; aromatic annelation; pyrido[2,3- b]-indoles
• ISSN: 0040-4020; 1464-5416
• DOI: 10.1016/S0040-4020(00)01054-1

The 3-[bis(methylthio)methylene]-1-methyloxindole (
2) is shown to undergo cycloaromatization with allyl and methallyl magnesium chlorides to afford substituted carbazoles. A novel route to 2-substituted-3-cyano-4-methylthio/aminopyrido[2,3-
b]indoles has been developed via heteroaromatic annelation of
2 with in situ generated 2-lithioamino-2-substituted acrylonitriles.
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