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Updated: Aug 9, 2026

Preparation of Contiguous Bisaziridines for Regioselective Ring-Opening Reactions
Published on: July 28, 2022
Effective preparation of cycloheptimidazol-4-one compounds
Motoharu Sonegawa1, Yoshinori Iwai, Hiroshi Tomiyama
1Kotobuki Research Laboratories, Kotobuki Seiyaku Company Ltd., 6351 Sakaki-Machi, Nagano 389-0697, Japan. ktb-g121@kotobuki-pharm.co.jp
Abstract:
Effective preparation of cycloheptimidazol-4-ones was developed. The reactions of 2-tosyloxytropone (5) with amidines (6) carried out under simple conditions such as aq. NaOH in toluene at 35 degrees C afforded the corresponding cycloheptimidazol-4-ones (3) in low yield. However, by adding tetra-n-butylammonium bromide (n-Bu(4)NBr) to this reaction system, the yield was improved dramatically. The reaction conditions were screened in detail.
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