Method for the preparation of alpha-fluorinated organic compounds from active hydrogen compounds

摘要

The invention comprises the compounds diethyl 2, 2-difluoromalonate, ethyl 2, 2-difluoroacetoacetate, diethyl 2-ethyl- and 2-phenyl-2-fluoromalonate, and 3, 3-difluoro-2, 4-pentanedione and its mono-2, 4-dinitro-phenylhydrazone; and a method for the preparation of a -fluorinated organic compounds by bringing together at a suitable temperature perchloryl fluoride ClO3F and an alkali metal derivative of an active hydrogen compound in which at least one active hydrogen atom has been replaced by an alkali metal atom, or the components of said derivative, namely an active hydrogen compound and an alkali metal base. An "active hydrogen compound" is defined as an organic compound containing a carbon atom to which is attached at least one hydrocarbon atom and at least one electron-accepting group. The corresponding compounds in which H is replaced by F are called "a -fluorinated compounds." An 'alkali metal base" is defined as any alkali metal compound which is sufficiently basic to remove the a -hydrogen atom from the starting compound, such as the alkoxides, hydroxide, hydride or amide, or the alkali metals themselves. Suitable active hydrogen compounds are those of the formula HCRR1R2, where R is hydrogen or a C1-12 aliphatic hydrocarbon or halogenohydrocarbon group, or a group sufficiently electronegative to render the compound capable of forming an alkali metal derivative, and R1 and R2 are separately or together such electronegative groups; specified electronegative groups are-CN, -CO.R3, -CR3=CR4R5, -COOR3, -CS.R3, -NO2 and where R3, R4 and R5 represent hydrogen, halogen, phenyl, or a C1-3 aliphatic hydrocarbon or halogenohydrocarbon group. Examples of active hydrogen compounds are b -diketones, b -keto-esters, b -diesters, b -thioketo-esters, nitriles, nitroalkanes and cycloalkadiene compounds. Non-aqueous solvents may be used in the reaction. In Examples, the following compounds are prepared: (1) diethyl 2, 2-difluoromalonate; (2) ethyl 2, 2-difluoroacetoacetate and its 2, 4-dinitrophenylhydrazone; (3) diethyl 2-ethyl-2-fluoromalonate; (4) difluoromalonitrile; (5) methyl ethyl 2, 2-difluoromalonate; (6) a , a -difluoro-cyanoacetic acid; (7) ethyl a , a -difluoro-cyanoacetate; (8) C3H7OCOCF(CH3)COOCH2Cl; (9) CH3OCO CF2CO.CH3CH2CHCl2; (10) propyl 2, 2-difluoroacetoacetate; (11) diethyl 2-fluoro-2-(p-chlorophenyl)-malonate; (12) diethyl 2-fluoro-2-aceto-malonate; (13) diethyl 2-fluoro-2-allylo-malonate; (14) methyl a , a -difluoro-nitroacetate; (15) a -cyanoa , a -difluorotoluene; (16) 9, 9-difluorofluorene; (17) 5, 5-difluorocyclopentadiene (18) 1, 1-difluoroindane; (19) and (21) CH3COCF2COCH3; (20) CH3O.CS.CF2.CS.OCH3; (22) diethyl-2-fluoro-2-phenyl malonate. 5-Ethyl-5-fluoro-barbituric acid is prepared by reacting diethyl 2-fluoro-2-ethylmalonate with urea. Difluoromalonamide is prepared by the action of ammonia on diethyl 2, 2-difluoromalonate.