Improved iminium based processes for the production of cyanoacrylates and methylidene malonates wherein the improvement pertains to the presence of acid chlorides and/or acid anhydrides in the reaction mix.

The present invention relates to a process for the preparation of substituted 4-(N′-hydroxy-carbamimidoyl)benzoic acids, which can be obtained by nitrilase catalyzed hydration of substituted terephthalonitriles of formula (II) in an aqueous medium to afford (ammonium) 4-cyanobenzoic acids (IIa). The hydration is followed by treatment of the aqueous reaction medium with hydroxylamine or a salt thereof to afford amidoximes (I).

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The present invention relates to a process for the preparation of substituted 4-(N′-hydroxy-carbamimidoyl)benzoic acids, which can be obtained by nitrilase catalyzed hydration of substituted terephthalonitriles of formula (II) in an aqueous medium to afford (ammonium) 4-cyanobenzoic acids (IIa). The hydration is followed by treatment of the aqueous reaction medium with hydroxylamine or a salt thereof to afford amidoximes (I).

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A process of stabilizing a bidentate or tridentate phosphorus-based phosphite ester ligand or mixture thereof in a hydrocyanation reaction milieu comprising water, wherein the ligand or ligand mixture comprises one or more of (i) a bidentate biphosphite ligand of formula (III), (R.sup.12—X.sup.12) (R.sup.13—X.sup.13) P—X.sup.14—Y—X.sup.24—P(X.sup.22—R.sup.22) (X.sup.23—R.sup.23) or (ii) a tridentate triphosphite ligand of formula (IIIA) (R.sup.12—X.sup.12) (R.sup.13—X.sup.13) P—X.sup.14—Y—X.sup.32—P(X.sup.34—R.sup.34)—(X.sup.33—Y.sup.2—R.sup.24—P(X.sup.23—R.sup.23)—(X.sup.22—R.sup.22) where each X is oxygen or a bond and each Y is an optionally substituted C6-C20 arylene group, comprising admixing the bidentate and/or tridentate with a stabilizing amount of one or more monodentate phosphite ligand of formula P(X.sup.1—R.sup.1)(X.sup.2—R.sup.2)(X.sup.3—R.sup.3) where each X is oxygen or a bond, wherein the monodentate ligand has a rate of hydrolysis greater than the rate of hydrolysis of the bidentate or tridentate ligand in the presence of water in a hydrocyanation reaction milieu, and thereby preserve concentrations and proportions of the bidentate and/or tridentate ligand(s) in the ligand blend.

A process of stabilizing a bidentate or tridentate phosphorus-based phosphite ester ligand or mixture thereof in a hydrocyanation reaction milieu comprising water, wherein the ligand or ligand mixture comprises one or more of (i) a bidentate biphosphite ligand of formula (III), (R.sup.12—X.sup.12) (R.sup.13—X.sup.13) P—X.sup.14—Y—X.sup.24—P(X.sup.22—R.sup.22) (X.sup.23—R.sup.23) or (ii) a tridentate triphosphite ligand of formula (IIIA) (R.sup.12—X.sup.12) (R.sup.13—X.sup.13) P—X.sup.14—Y—X.sup.32—P(X.sup.34—R.sup.34)—(X.sup.33—Y.sup.2—R.sup.24—P(X.sup.23—R.sup.23)—(X.sup.22—R.sup.22) where each X is oxygen or a bond and each Y is an optionally substituted C6-C20 arylene group, comprising admixing the bidentate and/or tridentate with a stabilizing amount of one or more monodentate phosphite ligand of formula P(X.sup.1—R.sup.1)(X.sup.2—R.sup.2)(X.sup.3—R.sup.3) where each X is oxygen or a bond, wherein the monodentate ligand has a rate of hydrolysis greater than the rate of hydrolysis of the bidentate or tridentate ligand in the presence of water in a hydrocyanation reaction milieu, and thereby preserve concentrations and proportions of the bidentate and/or tridentate ligand(s) in the ligand blend.

A preparation method of 1-(4-aminophenyl)cyclopentanecarbonitrile includes the following steps: step 1: in the presence of Li.sub.2CuCl.sub.4, adding a nitrochlorobenzene-zinc reagent dropwise to a 1-chlorocyclopentanecarbonitrile solution to prepare a compound 1-(4-nitrophenyl)cyclopentanecarbonitrile; and step 2: subjecting the compound 1-(4-nitrophenyl)cyclopentanecarbonitrile obtained in step 1 to a nitroreduction reaction under the action of a catalyst to prepare the compound 1-(4-aminophenyl)cyclopentanecarbonitrile. The preparation method involves cheap and easily-available raw materials, mild reaction conditions, and convenient operations, leads to high yield, and is environmentally-friendly and suitable for industrial large-scale production.

A preparation method of 1-(4-aminophenyl)cyclopentanecarbonitrile includes the following steps: step 1: in the presence of Li.sub.2CuCl.sub.4, adding a nitrochlorobenzene-zinc reagent dropwise to a 1-chlorocyclopentanecarbonitrile solution to prepare a compound 1-(4-nitrophenyl)cyclopentanecarbonitrile; and step 2: subjecting the compound 1-(4-nitrophenyl)cyclopentanecarbonitrile obtained in step 1 to a nitroreduction reaction under the action of a catalyst to prepare the compound 1-(4-aminophenyl)cyclopentanecarbonitrile. The preparation method involves cheap and easily-available raw materials, mild reaction conditions, and convenient operations, leads to high yield, and is environmentally-friendly and suitable for industrial large-scale production.

A preparation method of 1-(4-aminophenyl)cyclopentanecarbonitrile includes the following steps: step 1: in the presence of Li.sub.2CuCl.sub.4, adding a nitrochlorobenzene-zinc reagent dropwise to a 1-chlorocyclopentanecarbonitrile solution to prepare a compound 1-(4-nitrophenyl)cyclopentanecarbonitrile; and step 2: subjecting the compound 1-(4-nitrophenyl)cyclopentanecarbonitrile obtained in step 1 to a nitroreduction reaction under the action of a catalyst to prepare the compound 1-(4-aminophenyl)cyclopentanecarbonitrile. The preparation method involves cheap and easily-available raw materials, mild reaction conditions, and convenient operations, leads to high yield, and is environmentally-friendly and suitable for industrial large-scale production.

The present invention provides novel Ruthenium-based transition metal complex catalysts comprising specific ligands, their preparation and their use in hydrogenation processes. Such complex catalysts are inexpensive, thermally robust, and olefin selective.

The present invention provides novel Ruthenium-based transition metal complex catalysts comprising specific ligands, their preparation and their use in hydrogenation processes. Such complex catalysts are inexpensive, thermally robust, and olefin selective.