摘要:
A process for inhibiting polymerization of (meth)acrylic acid and/or (meth)acrylic esters by introducing an oxygenous gas into the (meth)acrylic acid and/or the (meth)acrylic ester, in which the (meth)acrylic acid and/or the (meth)acrylic ester has a degree of purity of at least 95% and is in the liquid state.
摘要:
A process for preparing tertiary alkyl esters of (meth)acrylic acid having at least 4 carbon atoms in the alkyl radical, comprising the steps of: (1) reacting (meth)acrylic acid with at least one olefin of the general formula I: in which R1 and R2 are an alkyl radical, and R3 is a hydrogen atom, an alkyl radical, a cycloalkyl radical, an aryl radical, an alkylcycloalkyl radical, an alkylaryl radical, a cycloalkylaryl radical, or an alkylcycloalkylaryl radical; in homogeneous phase in the presence of an acidic catalyst in a reactor, (2) discharging the resulting reaction mixture (1) from the reactor, (3) separating the discharged reaction mixture (2) into a mixture (3.1) which comprises the catalyst and a mixture (3.2) which comprises the tertiary alkyl ester of (meth)acrylic acid having at least 4 carbon atoms in the alkyl radical, and (4) removing the tertiary alkyl ester of (meth)acrylic acid having at least 4 carbon atoms in the alkyl radical from the mixture (3.2), wherein, (5) in process step (4), at least one compound S which comprises at least one N-oxyl group is added as a stabilizer.
摘要:
A process for preparing (meth)acrylic esters (F) of alcohols (A) having at least one epoxy group, in which at least one alcohol (A) having at least one epoxy group is esterified with (meth)acrylic acid (S) or is transesterified with at least one (meth)acrylic ester (D) in the presence of at least one enzyme, the alcoholic leaving group being stable under the reaction conditions in the case of the transesterification.
摘要:
A process for inhibiting polymerization of (meth)acrylic acid and/or (meth)acrylic esters by introducing an oxygenous gas into the (meth)acrylic acid and/or the (meth)acrylic ester, in which the (meth)acrylic acid and/or the (meth)acrylic ester has a degree of purity of at least 95% and is in the liquid state.
摘要:
A process for rectificatively separating a liquid which comprises acrylic acid, methacrylic acid or a mixture thereof, and additionally comprises low molecular weight aldehydes and acetone.
摘要:
The present invention to a process for preparing 1-phenylpyrazoles of the formula I in which each R1 is independently selected from chlorine, fluorine, alkyl, haloalkyl, alkoxy and haloalkoxy; n is 1, 2 or 3; each R2 is independently selected from cyano, nitro, halogen, alkyl, haloalkyl, alkoxy, haloalkoxy, alkylthio and alkoxycarbonyl; m is 0, 1 or 2; A is alkyl, aryl or aryl-C1-C4-alkyl, where A optionally bears 1, 2, 3 or 4 substituents comprising reacting a phenyl halide of the formula (II) with apyrazole derivative of the formula (III) in which X is chlorine, iodine or bromine; and R1, n, R2, m and A are each as defined above, in the presence of a base and a catalytic system comprising a ligand and a metal compound selected from palladium compounds, iron compounds and copper compounds.
摘要:
The present invention to a process for preparing 1-phenylpyrazoles of the formula I in which each R1 is independently selected from chlorine, fluorine, alkyl, haloalkyl, alkoxy and haloalkoxy; n is 1, 2 or 3; each R2 is independently selected from cyano, nitro, halogen, alkyl, haloalkyl, alkoxy, haloalkoxy, alkylthio and alkoxycarbonyl; m is 0, 1 or 2; A is alkyl, aryl or aryl-C1-C4-alkyl, where A optionally bears 1, 2, 3 or 4 substituents comprising reacting a phenyl halide of the formula (II) with apyrazole derivative of the formula (III) in which X is chlorine, iodine or bromine; and R1, n, R2, m and A are each as defined above, in the presence of a base and a catalytic system comprising a ligand and a metal compound selected from palladium compounds, iron compounds and copper compounds.
摘要:
The present invention relates to a process for preparing tertiary alkyl esters of (meth)acrylic acid having at least 4 carbon atoms in the alkyl radical. The process includes reacting (meth)acrylic acid with at least one olefin of formula (I) in homogeneous phase in the presence of an acidic catalyst in a reactor, discharging the resulting reaction mixture from the reactor, separating the discharged reaction mixture into a first mixture which contains the catalyst and a second mixture which contains the tertiary alkyl ester of (meth)acrylic acid having at least 4 carbon atoms in the alkyl radical, and removing the tertiary alkyl ester of (meth)acrylic acid having at least 4 carbon atoms in the alkyl radical from the second mixture in the presence of compound S, which comprises at least one N-oxyl group and is added as a stabilizer.