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    5.
    发明专利
    未知

    公开(公告)号：DE3244522A1

    公开(公告)日：1984-06-07

    申请号：DE3244522

    申请日：1982-12-02

    Applicant: BASF AG

    Inventor： BAUR KARL GERHARD DR ,  DIEHL VOLKER DR ,  STOPS PETER ,  HELLBACH HANS ,  BRUNNER ERWIN DR

    IPC: C07D213/82 ,  C07D213/803 ,  C07D213/81

    Abstract: A process for the preparation of nicotinamide by amidation of a nicotinic acid/nicotinamide melt, vacuum distillation of the amidation mixture, removal of the nicotinamide as the bottom product and recycling of the top product, depleted with respect to nicotinamide, into the amidation stage together with addition of fresh amounts of nicotinic acid.

    8.
    发明专利
    未知

    公开(公告)号：DE3314790A1

    公开(公告)日：1984-10-25

    申请号：DE3314790

    申请日：1983-04-23

    Applicant: BASF AG

    Inventor： HELLBACH HANS ,  MERGER FRANZ DR ,  TOWAE FRIEDRICH DR

    IPC: C07C265/14 ,  C07C67/00 ,  C07C69/00 ,  C07C241/00 ,  C07C263/04 ,  C07C263/06 ,  C07C265/10 ,  C07C119/045 ,  C07C118/00

    Abstract: This invention discloses a non-phosgene process for the preparation of 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate by the reaction of the precursor diamine with urea and an aliphatic alcohol in the presence of a dialkyl carbonate and an alkyl carbonate. The intermediate diurethane is separated from starting materials and by-products and thermally cleaved to alcohol and diisocyanate which are separated by fractional condensation of the products from the vapor state. This process gives high yields of the desired diisocyanate and lends itself particularly to continuous processing.

    9.
    发明专利
    未知

    公开(公告)号：DE3314788A1

    公开(公告)日：1984-10-25

    申请号：DE3314788

    申请日：1983-04-23

    Applicant: BASF AG

    Inventor： MERGER FRANZ DR ,  TOWAE FRIEDRICH DR ,  HELLBACH HANS ,  KOEHLER WALDEMAR DR ,  ISBARN GUNTHER DR

    IPC: C07C265/14 ,  C07C67/00 ,  C07C69/00 ,  C07C241/00 ,  C07C263/04 ,  C07C263/06 ,  C07C265/04 ,  C07C119/042 ,  C07C118/00

    Abstract: Hexamethylene diisocyanate and/or isomeric alkylene diisocyanates having 6 carbon atoms in the alkylene radical, preferably 2-methylpentamethylene 1,5-diisocyanate and/or 2-ethyltetramethylene 1,4-diisocyanate are prepared without the use of phosgene in a multiple-step process by means of (a) reacting hexamethylene 1,6-diamine and/or isomeric alkylene diamines having 6 carbon atoms in the alkylene radical with urea and alcohol in the presence of dialkyl carbonate and/or carbamic acid alkyl ester as well as, in some cases, catalysts to form hexamethylene 1,6-dialkylurethane and/or isomeric alkylene dialkylurethanes having 6 carbon atoms in the alkylene radical, (b) separation and return to reaction step (a) of alcohol, dialkyl carbonate, and/or carbamic acid alkyl ester from the reaction mixture (c) evaporation of the hexamethylene 1,6-dialkylurethane and/or isomeric alkylene dialkylurethanes having 6 carbon atoms in the alkylene radical, (d) cleavage of the vaporized diurethanes into hexamethylene diisocyanate and/or isomeric alkylene diisocyanate having 6 carbon atoms in the alkylene radical and alcohol, and (e) fractional condensation of the cleavage products.

    PREPARATION OF HEXAMETHYLENE 1,6-DIISOCYANATE AND/OR ISOMERIC DIISOCYANATES WHERE ALKYLENE IS OF 6 CARBON ATOMS
    10.
    发明专利
    PREPARATION OF HEXAMETHYLENE 1,6-DIISOCYANATE AND/OR ISOMERIC DIISOCYANATES WHERE ALKYLENE IS OF 6 CARBON ATOMS 未知

    公开(公告)号：CA1225998A

    公开(公告)日：1987-08-25

    申请号：CA432977

    申请日：1983-07-22

    Applicant: BASF AG

    Inventor： MERGER FRANZ ,  NESTLER GERHARD ,  TOWAE FRIEDRICH ,  HELLBACH HANS

    IPC: C07C263/04 ,  C07C265/04 ,  C08G18/73 ,  C07C119/042

    Abstract: Hexamethylene 1,6-diiso-cyanate and/or isomeric aliphatic diisocyanates where alkylene is of 6 carbon atoms, preferably 2-methylpenta-methylene 1,5-diisocyanate and/or 2-ethyltetramethylene 1,4-diisocyanate, are prepared by a process wherein the corresponding dialkylurethanes are vaporized, without decomposition, at from 220 to 300.degree.C, advantageously under reduced pressure, the dialkylurethane vapors are subjected to thermal cleavage under reduced pressure, preferably from 0.1 to 200 mbar, and at above 300.degree.C, preferably from 310 to 480.degree.C, in particular in the presence of a hydrogen halide and/or a donor which forms hydrogen halide under the reaction conditions, so that the hydrogen halide concentration during cleavage is from 0.001 to 1.0 mole %, based on the dialkylurethanes, and the cleavage products are fractionally condensed. The product obtained in the 1st condensation stage consists predominantly of the diisocyanates, while that obtained in the 2nd condensation stage is the alcohol.

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