中科微点-全球专利检索

  1. Login
  2. Sign Up

Search Results

16 records (took 0.02 seconds)

    DISTILLATIVE PURIFICATION OF 2,5-DIOXO-1-OXA-2-PHOSPHOLANES
    3.
    发明专利
    DISTILLATIVE PURIFICATION OF 2,5-DIOXO-1-OXA-2-PHOSPHOLANES 未知

    公开(公告)号：ZA764225B

    公开(公告)日：1977-07-27

    申请号：ZA764225

    申请日：1976-07-16

    Applicant: HOECHST AG

    Inventor： GEHRMANN K ,  OHORODNIK A ,  LOHMAR E ,  RIECHMANN W

    IPC: C07F9/32 ,  C07F9/34 ,  C07F9/6571 ,  C07F9/6574 ,  C07F

    Abstract: 2,5 DIOXO-1-OXA-2-PHOSPHOLANES OF THE GENERAL FORMULA: in which R1 stands for an alkyl radical having from 1 to 4 carbon atoms, or a phenyl radical, and R2 and R3 each stand for hydrogen or CH3, are distillatively purified. To this end the respective crude compound is preheated to 120 DEG to 160 DEG C and fed to the head of a distilling column provided with a plurality of individually heatable trays maintained at temperatures increasing from the upper-most tray to the lowermost, the uppermost tray in the column being maintained at 120 DEG to 160 DEG C and the lowermost tray being maintained at 160 DEG to 200 DEG C, the pressure at the head of the column being 20 to 200 mm Hg, preferably 50 to 120 mm Hg; an inert gas preheated to 160 DEG to 200 DEG C is introduced countercurrently at the base of the column; those impurities having a boiling point lower than that of the respective 2,5-dioxo-1-oxa-2-phospholane are withdrawn overhead together with the inert gas; the 2,5-dioxo-1-oxa-2-phospholane thus freed from low-boiling impurities is withdrawn from the base of the distilling column and passed to a film evaporator; and the 2,5-dioxo-1-oxa-2-phospholane is distilled off from higher-boiling impurities in the film evaporator under a pressure of 0.1 to 5 mm Hg.

    CONTINUOUS PRODUCTION OF 2,5-DIOXO-1-OXA-2-PHOSPHOLANES
    6.
    发明专利
    CONTINUOUS PRODUCTION OF 2,5-DIOXO-1-OXA-2-PHOSPHOLANES 未知

    公开(公告)号：ZA764087B

    公开(公告)日：1977-07-27

    申请号：ZA764087

    申请日：1976-07-09

    Applicant: HOECHST AG

    Inventor： GEHRMANN K ,  STUTZKE P ,  OHORODNIK A ,  LOHMAR E

    IPC: C07F9/32 ,  C07F9/34 ,  C07F9/6571 ,  C07F9/6574 ,  C07F

    Abstract: Continuous production of 2,5-dioxo-1-oxa-2-phospholanes of the general formula from a beta-halogenoformyl-ethyl phosphinic acid halide of the general formula R1XP(O)-CHR2-CHR3-CO-X in which formula R1 stands for an alkyl radical having 1, 2, 3 or 4 carbon atoms, or a phenyl radical, R2 and R3 each stands for hydrogen or CH3, and X stands for chlorine or bromine, by reacting the said acid halide with acetic anhydride. The phospho lanes are produced by introducing, into a heatable circulation reactor, an initial quantity of the desired 2,5-dioxo-1-oxa-2-phospholane and circulating it therein at a temperature of 110 DEG to 190 DEG C; separately preheating the respective beta-halogenoformyl-ethyl phosphonic acid halide and acetic anhydride starting materials to a temperature of 60 DEG to 160 DEG C; mixing these starting materials together and continuously adding the resulting mixture to the material circulated in the reactor, the mixture being introduced into the lower third of the reactor; distilling off resulting acetyl halide near the head of the circulation reactor, a pressure difference 0.1 to 5 bar, being established between the point of introduction of the mixture of starting materials and the overflow level in the circulation reactor, and the material being kept circulating by the evaporating acetyl halide; and removing the resulting desired 2,5-dioxo-1-oxa-2-phospholane from the reactor at a location which is below that at which the acetyl halide is distilled off.

Patent Agency Ranking