中科微点-全球专利检索

  1. Login
  2. Sign Up

Search Results

31 records (took 0.021 seconds)

    2.
    发明专利
    未知

    公开(公告)号：DE4029068A1

    公开(公告)日：1992-03-19

    申请号：DE4029068

    申请日：1990-09-13

    Applicant: HOECHST AG

    Inventor： DAPPERHELD STEFFEN DR ,  HEUMUELLER RUDOLF DR ,  ULMSCHNEIDER DIETER DR ,  WILDT MANFRED

    IPC: C25B3/28 ,  C25B3/25

    Abstract: A process is disclosed for producing by electrolytic reduction compounds having formula (I), in which R is a fluorine atom, a methyl or a deuteromethyl group; R and R are the same or different and represent a fluorine, chlorine, hydrogen or deuterium atom; R is a group (a), in which R is -OH, -OD, C1-C4-alkoxy or -OMe, whereas Me represents an alkaline, alkaline earth or NH4 ion. For this purpose, a compound having formula (II) or a compound having formula (III), in which R , R , R and R have the above-mentioned meaning, whereas R is a chlorine atom, are subjected to an electrolytic process in a one-piece or subdivided cell filled with an electrolytic liquid, in the presence of an iron salt concentration of 1 to 500 ppm in the electrolyte.

    3.
    发明专利
    未知

    公开(公告)号：DE3802745A1

    公开(公告)日：1989-08-03

    申请号：DE3802745

    申请日：1988-01-30

    Applicant: HOECHST AG

    Inventor： DAPPERHELD STEFFEN DR ,  HEUMUELLER RUDOLF DR

    IPC: C25B3/25

    Abstract: Process for manufacturing fluoromalonic acid and its derivatives of the formula characterised in that compounds of the formula where R is a halogen with an atomic weight of 35 to 127, and R and R are identical or different and are hydroxyl, the group OX, where X is an alkali metal, alkaline earth or NH4 ion or a C1-C12-alkyl radical or is the group NR R , where R and R are identical or different and are hydrogen or a hydrocarbon radical containing 1 to 12 C atoms, are electrolysed at a temperature from -20 DEG C to the boiling point of the electrolyte at a current density of 1 to 600 mA/cm at a cathode composed of lead, cadmium, zinc, copper, tin, zirconium, mercury, alloys of at least two of these metals or carbon in an electrolyte liquid which is composed of water and/or an organic solvent.

    4.
    发明专利
    未知

    公开(公告)号：DE3704915A1

    公开(公告)日：1988-08-25

    申请号：DE3704915

    申请日：1987-02-17

    Applicant: HOECHST AG

    Inventor： DAPPERHELD STEFFEN DR ,  HEUMUELLER RUDOLF DR ,  WILDT MANFRED

    IPC: C25B3/25 ,  C25B3/00 ,  C07C57/54

    Abstract: The existing processes for the preparation of halogenoacrylic acids and deuterated derivatives thereof have to be carried out using chemicals which are in some cases very toxic or very expensive. Electrochemical reduction, however, makes it possible to eliminate one or more halogen atoms selectively from halogenoacrylic and halogenomethacrylic acids and derivatives thereof, and to replace these by hydrogen or deuterium atoms. This is effected by electrolyzing the acids or derivatives thereof in a solution containing water or deuterium oxide at a temperature from -10 DEG C. up to the boiling point of the electrolysis liquid.

    9.
    发明专利
    未知

    公开(公告)号：DE3868204D1

    公开(公告)日：1992-03-12

    申请号：DE3868204

    申请日：1988-09-17

    Applicant: HOECHST AG

    Inventor： DAPPERHELD STEFFEN DR ,  HEUMUELLER RUDOLF DR ,  WILDT MANFRED

    IPC: C25B3/28 ,  C25B3/25 ,  C25B3/04

    Abstract: Process is claimed for the prepn. of acrylate and methacrylate derivs. of forula (I) b electrolytic dehalogenation of propionic acid derivs. of formula (II) where R1 = F, CH3 or CO3, pref. F. R2 and R3 = independently, F, Cl, Br, I, H or D. R4 = -CN or -COR5. R5 = -OH; -OD; -OM where M = alkali metal, alkaline earth or NH4+ ion; 1-12C (1-6C), alkoxy; or -NR6R7. R6 and R7 = independently, H; D; 1-12C, (1-6C) alkyl; phenyl. R8 and R9 = independently Cl, Br or I. The electrolysis may be carried out in an open or partitioned cell using an electrolyte comprising the following (whole electrolyte in open cell or catholyte in partitioned cell): 0-100% water, 100-0% organic solvent(s) 0-10% metallic salt with H overpotential of at least 0.25V (at current density of 300 mA/cm2). The cell is run at -10 deg.C b.pt. of the electrolyte at constant current with a current density of 1-600 mA/cm2. In an open cell, the electrolysis may be performed with discontinuous cathode-and continuous anode-reactions. The cathode is pref. made of O, and the electrolysis may be facilitated either by addn. of soluble salts of certain metals or by adjustment of pH (see details below).

    10.
    发明专利
    未知

    公开(公告)号：DE3863794D1

    公开(公告)日：1991-08-29

    申请号：DE3863794

    申请日：1988-02-11

    Applicant: HOECHST AG

    Inventor： DAPPERHELD STEFFEN DR ,  HEUMUELLER RUDOLF DR ,  WILDT MANFRED

    IPC: C25B3/25 ,  C25B3/04

    Abstract: The existing processes for the preparation of halogenoacrylic acids and deuterated derivatives thereof have to be carried out using chemicals which are in some cases very toxic or very expensive. Electrochemical reduction, however, makes it possible to eliminate one or more halogen atoms selectively from halogenoacrylic and halogenomethacrylic acids and derivatives thereof, and to replace these by hydrogen or deuterium atoms. This is effected by electrolyzing the acids or derivatives thereof in a solution containing water or deuterium oxide at a temperature from -10 DEG C. up to the boiling point of the electrolysis liquid.

Patent Agency Ranking