A study on the conversion of indanones into carbostyrils.
We have surveyed the utility of Beckmann rearrangement for the conversion of indanones into carbostyrils. Initial attempts at the conversion of 6-methoxy indanone oxime under classical conditions resulted in the formation of the two unusual products: 2-sulfonyloxyindanone and the dimeric product. This unusual rearrangement was also observed by the treatment of some metal triflates species. Further investigation has led to the development of reliable conditions starting from oxime mesylate (not oxime tosylate), in which some strong Lewis acid catalyst (ZrCl(4)) was employed in either a conventional or non-conventional solvent system. The advantage of the new protocol is highlighted by the simple work up and direct isolation of the product in 65% isolated yield.
Torisawa
Yasuhiro
Y
Process Research Laboratory, Second Tokushima Factory, Otsuka Pharmaceutical Co., Ltd., Kawauchi, Tokushima, 771-0182, Japan. torisawa@fact.otsuka.co.jp
Nishi
Takao
T
Minamikawa
Jun ichi
Ji
D000476:Alkanesulfonates / Q000737:chemistry; D002384:Catalysis; D002712:Chlorides; D006912:Hydroxyquinolines / Q000138:chemical synthesis* / Q000494:pharmacology; D007189:Indans / Q000737:chemistry* / Q000494:pharmacology; D007536:Isomerism; D008698:Mesylates / Q000737:chemistry; D008670:Metals / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry; D010091:Oximes / Q000737:chemistry*; D015363:Quinolones; D012997:Solvents; D015040:Zirconium
D000476:Alkanesulfonates; D002712:Chlorides; D006912:Hydroxyquinolines; D007189:Indans; D008698:Mesylates; D008670:Metals; D009942:Organometallic Compounds; D010091:Oximes; D015363:Quinolones; D012997:Solvents; C010064:carbostyril; D015040:Zirconium; C012077:trifluoromethanesulfonic acid; C429984:zirconium chloride