RESUMO
Reaction of hexafluorocyclotriphosphazene (N3P3F6) with trimethyl(trifluoromethyl)silane in the presence of a catalytic amount of cesium fluoride in THF produced hexakis(trifluoromethyl)cyclotriphosphazene [N3P3(CF3)6] in 90% isolated yield. N3P3(CF3)6 is fully characterized by melting point, IR, NMR (19F, 13C, 31p), MS, and elemental analysis data. Single-crystal X-ray structures of N3P3(CF3)6 and N3P3F6 are reported.
RESUMO
A series of pyrimidine methyl and polyfluoroalkyl ethers were synthesized from the reactions of trifluoroamine oxide (1) with several 5-substituted uracils in the presence of tetrabutylammonium hydroxide and methanol, 2,2,2-trifluoroethanol (6), or 1H,1H-pentafluoropropanol (7). With 5-(trifluoromethyl)uracil (2), the new ethers formed were 5-fluoro-5-(trifluoromethyl)-6-methoxypyrimidine-2,4-dione (8), 5-fluoro-5-(trifluoromethyl)-6-(trifluoroethoxy)pyrimidine-2,4-dione (9), and 5-fluoro-5-(trifluoromethyl)-6-(1H,1H- pentafluoropropoxy)pyrimidine-2,4-dione (10). With 5-chlorouracil (3), the new ethers 5-chloro-5-fluoro-6-methoxypyrimidine-2,4-dione (11), 5-chloro-5-fluoro-6-(trifluoroethoxy)pyrimidine-2,4-dione (12), and 5-chloro-5-fluoro-6-(1H,1H-pentafluoropropoxy)pyrimidine-2,4-dione (13) were obtained. With 5-fluorouracil (4), the new ethers 5,5-difluoro-6-methoxypyrimidine-2,4-dione (14), 5,5-difluoro-6-(trifluoroethoxy)pyrimidine-2,4-dione (15) and 5,5 difluoro-6-(1H,1H-pentafluoropropoxy)pyrimidine-2,4-dione (16) were found. By reaction of 5-nitrouracil (5), the new ethers 5-nitro-5-fluoro-6 methoxypyrimidine-2,4-dione (17), 5-nitro-5-fluoro-6-(trifluoroethoxy)pyrimidine-2,4-dione (18), and 5-nitro-5-fluoro-6-(1H,1H-pentafluoropropoxy)pyrimidine-2,4-dione (19) were obtained. Each of the new compounds was characterized by using IR, 19F and 1H NMR, and mass spectroscopy, and elemental analysis. A single-crystal X-ray diffraction study of 8 was helpful in confirming compound structure.
RESUMO
A high-pressure liquid chromatographic procedure for the simultaneous determination of niacin, niacinamide, pyridoxine, thiamine, and riboflavin was developed and applied to the analysis of multivitamin blends for these water-soluble vitamins. Reversed-phase ion-pair chromatography, using sodium hexanesulfonate as the counterion, was employed. Analysis time is shortened considerably and precision is improved by the application of this analytical technique as compared to the current official methods of analysis. Involved sample pretreatment is not required.