Online article for Non-subscribers

Pay per view

Heterocycles has a pay-per-view service for Non-subscribers.
You will be able to directly purchase the full text article through PayPal.
Your purchased Paper can be downloaded after the payment is completed.
An e-mail will be sent the URL to download the paper.
If you have any questions, please contact: purchase@heterocycles.com

Price: ¥ 4,400 (Yen only)
Period: This Article can be accessed for 7 days.

Paper | Special issue | Vol 44, No. 1, 1997, pp.169-176
Published online, 1st January, 1970
DOI: 10.3987/COM-95-S4
Reduction of Indigo: Simple Syntheses of 3-Acetoxy-, 1-Acetyl-2,3-dihydro-, 3-Acetoxy-3'-acetyl-, 3-Acetoxy-1,3'-diacetyl-2,2'-bisindoles, and 2,2'-Bisindole

Masanori Somei,* Hiroyuki Hayashi, and Shinobu Ohmoto

*Faculty of Pharmaceutical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-0934, Japan

Abstract

Indigo was converted to 2,2’-bisindole by the direct reduction with zinc in acetic acid and acetic anhydride under argon or hydrogen atmosphere. Reduction with tin and iron afforded 3-acetoxy-2,2’-bisindole predominantly. Useful building blocks such as 1-acetyl-2,3-dihydro-, 3-acetoxy-3’-acetyl-, and 3-acetoxy-1,3’-diacetyl-2,2’-bisindoles were also produced depending on metal and reaction conditions.