摘要:
Partially hydrogenated derivatives of 2-nitro-1,1,1-trifluoroalkanes, in particular 2-oximino- and 2-hydroxylamino-1,1,1-trifluoroalkanes, are prepared by catalytically hydrogenating 2-nitro-1,1,1-trifluoroalkanes until a maximum of 2.2 moles of hydrogen per mole of 2-nitro-1,1,1-trifluoroalkane have reacted.
摘要:
In the conjugated nitrofluorination of an olefin by reacting an olefin of the formula ##STR1## in which R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each independently is hydrogen, fluorine, chlorine, bromine, alkyl, halogenoalkyl or cycloalkyl, orR.sup.2 and R.sup.4 together are an alkylene radical of 3 to 6 carbon atoms,with hydrogen fluoride and nitric acid to produce an .alpha.-fluorinated nitroalkane of the formula ##STR2## the improvement which comprises effecting the reaction in a vessel protected against corrosion employing about 1 to 1.1 mols of hydrogen fluoride and about 1 to 2 mols of nitric acid per mol of olefin. The process uses much less HF than heretofore and the products are useful intermediates in making herbicides. Some of the products are new.
摘要:
In the preparation of an .alpha.-fluorinated nitroalkane of the formula ##STR1## in which R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical or different and individually represent hydrogen, fluorine, chlorine, bromine, alkyl, halogenoalkyl or cycloalkyl, orR.sup.1 and R.sup.3 have the meaning indicated andR.sup.2 and R.sup.4 together represent an alkylene group having 3-6 carbon atoms,by conjugated nitrofluorination of the corresponding olefin of the formula ##STR2## the improvement which comprises employing about 1.1 mols of hydrogen fluoride and 1 to 2 mols of nitric acid per mol of olefin and carrying out the reaction in the presence of an agent which binds water, e.g. chlorosulphonic acid, fluorosulphonic acid, sulphur trioxide, sulphur dioxide, thionyl chloride, thionyl fluoride, sulfuryl chloride or sulfuryl fluoride. The end products, some of which are known, are useful as intermediates in synthesizing herbicides.
摘要:
In the preparation of 3-bromo-4-fluorotoluene by reacting 4-fluorotoluene with bromine, the improvement which comprises effecting the bromination in glacial acetic acid in the presence of iodine and iron or an iron salt. As a result the proportion of 3-bromo-4-fluorotoluene relative to its 2-bromo-4-fluorotoluene isomer is markedly increased.
摘要:
Chlorine-containing pyrimidines are selectively hydrogenated with elimination of hydrogen chloride, without other substituents and/or the aromatic ring being significantly attacked, by using a hydrogenation catalyst and a hydrogen chloride acceptor. This process gives predominantly new pyrimidines.
摘要:
5-fluorocytosine is prepared by reacting 2,5-difluoro-4-chloro-pyrimidine with a proton acid in the presence of water to yield 2-hydroxy-4-chloro-5-fluoropyrimidine and reacting the 2-hydroxy-4-chloro-5-fluoropyrimidine with ammonia to yield 5-fluoro-cytosine.
摘要:
Pyrimidines substituted in the 5-position by fluorine, some of which are new, are prepared from pyrimidines of the formula ##STR1## in which R.sup.1 and R.sup.2 are identical or different and denote fluorine or trifluoromethyl,by stepwise reaction with hydrogen chloride.
摘要:
Process for the preparation of benzal chlorides from benzotrichlorides, according to which benzotrichlorides are reacted with thiols in the presence of metal salts at elevated temperatures.
摘要:
New fluorinated azomethines of the general formula ##STR1## in which X.sup.1 represents hydrogen, fluorine or chlorine,X.sup.2 represents hydrogen, fluorine or chlorine,R.sup.1 represents hydrogen or alkyl andR.sup.2 represents hydrogen or alkyl,a process for their preparation and their use as intermediate products.