Effective preparation of cycloheptimidazol-4-one compounds.
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.
Sonegawa
Motoharu
M
Kotobuki Research Laboratories, Kotobuki Seiyaku Company Ltd., 6351 Sakaki-Machi, Nagano 389-0697, Japan. ktb-g121@kotobuki-pharm.co.jp
Iwai
Yoshinori
Y
Tomiyama
Hiroshi
H
Tomiyama
Tsuyoshi
T
D002384:Catalysis; D003508:Cycloheptanes / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D012997:Solvents; D013055:Spectrophotometry, Infrared; D013696:Temperature
D003508:Cycloheptanes; D007093:Imidazoles; D007202:Indicators and Reagents; D012997:Solvents; C511395:cycloheptimidazol-4-one