alpha,alpha-gem-Difluorination of alpha-(alkylthio)acetophenone derivatives with N-fluoropyridinium salts.
The alpha,alpha-gem-difluorination of 2',4'-difluoro-alpha-(methylthio)acetophenone (1a) with N-fluoropyridinium salts gave 2',4',alpha,alpha-tetrafluoro-alpha-(methylthio)acetophenone (3a). This reaction was accelerated by the addition of zinc chloride, zinc bromide or anhydrous iron(III) chloride, and higher yields than the reaction without additives were obtained. The gem-difluorination reaction using FP-T300 in the presence of zinc bromide was applicable to other alpha-(alkylthio)acetophenone derivatives (1).
Central Research Laboratory, SS Pharmaceuticals Co, Ltd, Narita, Chiba, Japan. Sunao.Takeda@ssp.co.jp
S
S
Takeda
Y
Y
Kaneko
H
H
Eto
M
M
Tokizawa
S
S
Sato
K
K
Yoshida
S
S
Namiki
M
M
Ogawa
D000098:Acetophenones / Q000737:chemistry*; D000473:Alkanes / Q000737:chemistry*; D001965:Bromides / Q000737:chemistry; D002712:Chlorides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D011725:Pyridines / Q000737:chemistry*; D017967:Zinc Compounds / Q000737:chemistry*
D000098:Acetophenones; D000473:Alkanes; D001965:Bromides; D002712:Chlorides; D011725:Pyridines; D017967:Zinc Compounds; C016837:zinc chloride; C093802:zinc bromide