Room‐Temperature, Metal‐Free, and One‐Pot Preparation of 2H‐Indazoles through a Mills Reaction and Cyclization Sequence. Issue 42 (1st July 2019)

• Record Type: Journal Article
• Authors: Kondo, Masaru; Takizawa, Shinobu; Jiang, Yuzhao; Sasai, Hiroaki
• Is Part Of: Chemistry. Volume 25:Issue 42(2019)
• Page Start: 9866
• Page End: 9869
• Publication Date: 2019-07-01
• Subjects: cyclization -- indazole -- metal-free synthesis -- nitrogen heterocycles -- one-pot reaction; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201902242
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: The Mills reaction and cyclization of readily available 2‐aminobenzyl alcohols and nitrosobenzenes using thionyl bromide provided 2 H ‐indazoles in up to 88 % yields. In the metal‐free process, acetic acid played a crucial role for the both Mills reaction and cyclization. A brominated 2 H ‐indazole could also be obtained through the one‐pot sequence. Abstract : Heterocycles : The Mills reaction and cyclization of readily available 2‐aminobenzyl alcohols and nitrosobenzenes using thionyl bromide provided 2 H ‐indazoles in up to 88 % yields (see scheme). In the metal‐free process, acetic acid played a crucial role for the both Mills reaction and cyclization. A brominated 2 H ‐indazole could also be obtained through the one‐pot sequence.