Synthesis of 5-Substituted Indole Derivatives. Part 4: Naratriptan from α-Anilinoacetaldehyde Dimethylacetal by TiCl4-Mediated Cyclisation
摘要:
N-Methyl-3-(1-methyl-4-piperidinyl)-1H-indole-5-ethanesulfonamide (Naratriptan, 2) was prepared from N-methyl-N-phenylmethyl-2-(4-aminophenyl)ethanesulfonamide (3b) through reductive alkylation with dimethoxyacetaldehyde followed by N-acylation and TiCl4-mediated indolisation, according to Sundberg procedure. The isopropyl group proved to be a useful protecting group for sulfonate esters in a number of transformations but was cleaved in the presence of TiCl4.
Synthesis of 5-Substituted Indole Derivatives. Part 4: Naratriptan from α-Anilinoacetaldehyde Dimethylacetal by TiCl4-Mediated Cyclisation
摘要:
N-Methyl-3-(1-methyl-4-piperidinyl)-1H-indole-5-ethanesulfonamide (Naratriptan, 2) was prepared from N-methyl-N-phenylmethyl-2-(4-aminophenyl)ethanesulfonamide (3b) through reductive alkylation with dimethoxyacetaldehyde followed by N-acylation and TiCl4-mediated indolisation, according to Sundberg procedure. The isopropyl group proved to be a useful protecting group for sulfonate esters in a number of transformations but was cleaved in the presence of TiCl4.
[EN] NOVEL PROCESS FOR THE PREPARATION OF NARATRIPTAN HYDROCHLORIDE<br/>[FR] NOUVEAU PROCÉDÉ DESTINÉ À LA PRÉPARATION DE NARATRIPTAN
申请人:NATCO PHARMA LTD
公开号:WO2008056378A2
公开(公告)日:2008-05-15
[EN] Present invention provides a novel and improved process for the preparation of N- methyl-1H-indole-5-ethanesulfonamide of formula (I). Compound of formula (I) is a key intermediate used in the synthesis of naratriptan hydrochloride of formula (II). Hydrazone derivative of formula (XL) derived from the corresponding hydrazine and pyruvate ester is reacted with an acid catalyst to get the indole-2-carboxylate derivative of formula (XLI). Hydrolysis of this ester and decarboxylation gave the compound of formula (I). Naratriptan hydrochloride (Amerge) is widely used as anti-migraine drug in the market. [FR] La présente invention concerne un nouveau procédé amélioré destiné à la préparation de N- méthyl-1H-indole-5-éthanesulfonamide représenté par la formule (I). Le composé représenté par la formule (I) est un intermédiaire clé utilisé dans la synthèse de naratriptan représenté par la formule (II). On fait réagir un dérivé d'hydrazone représenté par la formule (XL) dérivé de l'hydrazine et de l'ester de pyruvate correspondants avec un catalyseur acide afin d'obtenir le dérivé d'indole-2-carboxylate représenté par la formule (XLI). On obtient le composé représenté par la formule (I) par hydrolyse et décarboxylation de cet ester. Le naratriptan (Amerge) est largement utilisé en tant que médicament antimigraineux sur le marché.
Synthesis of 5-Substituted Indole Derivatives. Part 4: Naratriptan from α-Anilinoacetaldehyde Dimethylacetal by TiCl4-Mediated Cyclisation
N-Methyl-3-(1-methyl-4-piperidinyl)-1H-indole-5-ethanesulfonamide (Naratriptan, 2) was prepared from N-methyl-N-phenylmethyl-2-(4-aminophenyl)ethanesulfonamide (3b) through reductive alkylation with dimethoxyacetaldehyde followed by N-acylation and TiCl4-mediated indolisation, according to Sundberg procedure. The isopropyl group proved to be a useful protecting group for sulfonate esters in a number of transformations but was cleaved in the presence of TiCl4.