Process for manufacturing 1-cyclopropyl-naphthalenes
AssigneePatheon Austria GmbH & Co KG
InventorKarl-Heinz Giselbrecht
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Abstract
A process for preparing 1-cyclopropyl-naphthalene derivatives of Formula (1) wherein R1-R7 are independently hydrogen, alkyl, alkoxy, cycloalkyl or aryl comprising the steps of a) contacting an acid salt of a 1-naphthyl-2-aminoethylketone with a base and a first solvent to obtain a solution wherein the molar ratio of base to 1-naphthyl-2-aminoethylketone acid salt is at least 0.7, b) addition of hydrazine to obtain a 3-(1-naphthyl)-1H-pyrazoline, c) optionally adding a second solvent and/or at least partially removing the first solvent, and d) heating the reaction mixture to a temperature above 190° C. to obtain the compound of Formula (1).
Claims9
A process for preparing a compound of Formula (1)
- comprising the steps of
- a) contacting a compound of Formula (2)
- with a base and a first solvent to obtain a solution wherein a molar ratio of base to compound of Formula (2) is at least 0.7 and at most 1.3, wherein the first solvent is selected from the group consisting of triethylene glycol, sulfolane, propylene carbonate, ethylene glycol, diethylene glycol, methyl tert-butyl ether, dimethylformamide, dimethylacetamide and quinoline;
- b) addition of hydrazine to the solution to obtain a compound of Formula (3)
- c) adding a second solvent that is different from the first solvent to the solution and/or at least partially removing the first solvent from the solution thereby obtaining a reaction mixture;
- and
- d) heating the reaction mixture to a temperature above 190° C. in the absence of a catalyst to obtain the compound of Formula (1), wherein the steps b) and c) are optionally performed concurrently;
- and wherein R1-R7 are independently hydrogen or C1-8 alkyl, C1-6 alkoxy, C3-6 cycloalkyl or C5-10 aryl, R8 and R9 are independently hydrogen or C1-8 alkyl;
- and X is a counter ion.
Dependencies are inferred from the claim text.