摘要:
2,6-Difluoroaniline is prepared from 1,2,3-trichlorobenzene by partial fluorine exchange to a mixture of 2,6-difluorochlorobenzene and 2,3-difluorochlorobenzene, selective reduction to a mixture of 2,6-difluorochlorobenzene and ortho -difluorobenzene, and amination to 2,6-difluoroaniline. The undesirable 2,3-difluorochlorobenzene is converted into valuable ortho -difluorobenzene and the 2,3-difluoroaniline isomer is avoided.
摘要:
3-Mercapto-5-amino-(1H)-1,2,4-triazole is prepared by the rearrangement of 2,5-diamino-1,3,4-thiadiazole. The rearrangement proceeds in high yields under aqueous alkaline conditions.
摘要:
N-(3-(((2,6-Dihalophenyl)amino)sulfonyl)-1H-1,2,4-triazol-5-yl)amines, intermediates for the preparation of herbicidal substituted 1,2,4-triazolo(1,5-a)pyrimidine-2-sulfonanilides, are directly prepared from an appropriately substituted 4-bromoaniline and a protected 5-amino-1,2,4-triazole-3-sulfonyl chloride. The improved reaction scheme involves the individual reaction steps of (a) coupling, (b) halogenation and (c) reduction.
摘要:
2,6-Difluoroaniline is prepared from 1,2,3-trichlorobenzene by partial fluorine exchange to a mixture of 2,6-difluorochlorobenzene and 2,3-difluorochlorobenzene, selective reduction to a mixture of 2,6-difluorochlorobenzene and ortho -difluorobenzene, and amination to 2,6-difluoroaniline. The undesirable 2,3-difluorochlorobenzene is converted into valuable ortho -difluorobenzene and the 2,3-difluoroaniline isomer is avoided.
摘要:
3,4-Difluoro substituted benzenes are prepared by reacting 3,4-dihalo substituted benzenes with an effective amount of KF or CsF, in a polar aprotic solvent, at an elevated temperature, under substantially anhydrous conditions. The product can be removed as it is formed or the reaction may be run at the autogenous pressures generated by the reaction mixture in a sealed reactor.