Gallium fluorination

The gallium(lll) triflate-mediated condensation of anthranilic acid with fluorinated ketones gave the corresponding 2,2-disubstituted l,2-dihydro-4//-3,l-benzoxazin-4-ones in high yields <20070L179>. 

List these bonds in order of increasing polarity P-F, S-F, Ga-F, Ge-F (F, fluorine, atomic number g P, phosphorus, atomic number 15 S, sulfur, atomic number 16 Ga, gallium, atomic number 31 Ge, germanium, atomic number 32) ... 

Benzothiazolines 72 are prepared by means of gallium(III) triflate mediated condensation of 2-aminobenzenethiol with fluorinated ketones followed by cyclization <07OL179>. Gallium triflate is a stable, water tolerant, recoverable, reusable, and environmentally friendly Lewis acid. Even when used in catalytic amounts, gallium triflate provides sufficient acidity required for the synthesis of fluorinated benzothiazolines. 

The commercially available materials, HC1, (CH3)3A1, and CF3CC>2H, were purified by trap-to-trap distillation in the vacuum line. S03 was generated as needed by passing the vapors from a sample of Sulfan B over a P205 column. Trimethylgallium was prepared by the reaction of gallium with dimethylmercury at 130° C. Difluoramine was prepared by the thiophenol reduction of tetrafluorohydrazine (3). Methyldifluoramine was obtained by fluorinating sodium N-methyl sulfamate. 

T. Loiseau and G. Ferey, Synthesis and Crystal Structure of ULM-16, a New Open-framework Fluorinated Gallium Phosphate with 16-Ring Channels Ga4(P04)4F2.1. 5NC6H14.0.5H20.0.5H30. J. Mater. Chem., 1996, 6, 1073-1074. 

C. Sassoye, T. Loiseau, F. Taulelle, and G. Ferey, A New Open-framework Fluorinated Gallium Phosphate with Large 18-Ring Channels (MIL-31). Chem. Commun., 2000, 943-944. 

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