Synthesis of carbazoles via an intramolecular cyclization of 2-(6-substituted 3(Z)-hexen-1,5-diynyl)anilines and their related molecules.
Various 2-(6-substituted 3(Z)-hexen-1,5-diynyl)anilines 1a-g were treated with potassium tert-butoxide or potassium 3-ethylpentanoxide in NMP at 60 degrees C for 2 h to give the corresponding 5-substituted carbazoles 2a-g in 36-65% yields together with indoles 9a-g in 21-40% yields, respectively. Exposing the trifluoroacetamide analogues 10h-k under the same reaction conditions gave the carbazoles 2b-e in 37-57% yields and indoles 9b-e in 15-27% yields. Subsequent cyclizations of acetamide analogues 10a-g gave carbazoles 2a-g in 53-86% yields.
Lee
Chia-Ying
CY
Faculty of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung, Taiwan.
Lin
Chi-Fong
CF
Lee
Jeng-Lin
JL
Chiu
Ching-Chen
CC
Lu
Wen-Der
WD
Wu
Ming-Jung
MJ
D000081:Acetamides / Q000737:chemistry; D000085:Acetates / Q000737:chemistry; D000475:Alkenes / Q000737:chemistry*; D000480:Alkynes / Q000737:chemistry*; D000814:Aniline Compounds / Q000737:chemistry*; D000970:Antineoplastic Agents / Q000138:chemical synthesis*; D000440:Butanols / Q000737:chemistry; D002227:Carbazoles / Q000138:chemical synthesis*; D002712:Chlorides / Q000737:chemistry; D003500:Cyclization; D005463:Fluoroacetates; D007211:Indoles / Q000138:chemical synthesis; D014269:Trifluoroacetic Acid / Q000737:chemistry
D000081:Acetamides; D000085:Acetates; D000475:Alkenes; D000480:Alkynes; D000814:Aniline Compounds; D000970:Antineoplastic Agents; D000440:Butanols; D002227:Carbazoles; D002712:Chlorides; D005463:Fluoroacetates; D007211:Indoles; C030688:trifluoroacetamide; C077664:tert-butoxide, potassium; C117224:1-hexene; D014269:Trifluoroacetic Acid; C081124:acetyl chloride; C023650:aniline