Patent ID: 9045433
Filing Date: 2015-06-02
Classification: C07D

Abstract:
1. A method for the preparation of medetomidine, the method comprises a step (N) and a step (M1); step (M1) comprises a reaction (M1-reac); reaction (M1-reac) is a reaction between a compound selected from the group consisting of a compound of formula (XXI), a hydrate of the compound of formula (XXI) and a hemiacetal of the compound of formula (XXI), said hemiacetal of the compound of formula (XXI) being the product of an addition reaction between the aldehyde as depicted in formula (XXI) and an alcohol selected from the group consisting of test-butanol and isopropanol, and a reagent (M-reag) and a reagent (M-A) in a solvent (M-solv); reagent (M-reag) is selected from the group consisting of p-toluenesulfonylmethyl isocyanide, trifiuoromethanesulfonylmethyl isocyanide, methanesulfonylmethyl isocyanide, benzenesulfonylmethyl isocyanide, 4-acetamidobenzenesulfonylmethyl isocyanide and mixtures thereof; reagent (M-A) is selected from the group consisting of ammonia, sulfamic acid, p-toluenesulfonamide, benzenesulfonamide, 4-acetamidobenzenesulfonamide, tritylamine, formamide, urea, urotropine, ethyl carbamate, acetamide and mixtures thereof; solvent (M-solv) is selected from the group consisting of N,N-dimethylformamide, C and wherein the compound of formula (XXI) is prepared in the step (N); step (N) comprises a reaction (N-reac); reaction (N-reac) is a reaction of a compound of formula (XXII) with a catalyst (N-cat); catalyst (N-cat) is selected from the group consisting of acetic acid, formic acid, trifluoroacetic acid, methanesulfonic acid, benzenesulthnic acid, p-toluenesulfonic acid, camphorsulfonic acid, HCI, HBr, H