Process for the preparation of 6-(2,3-dichlorophenyl)-1,2,4-triazine-3,5-diamine, commonly known as lamotrigine
申请人:RPG Life Sciences Limited
公开号:US06639072B1
公开(公告)日:2003-10-28
A process for the preparation of 6-(2,3-dichlorophenyl)-1,2,4-triazine-3-5-diamine (lamotrigine) of the formula I:
2,3-Dichloronitrobenzene in C1-C6 aliphatic alkanol is hydrogenated at 55-90 psi gas pressure using metal catalyst at 27-35° C. 2,3-Dichloroaniline is diazotised and cyano-de-diazonised with metal cyanide at 65-80° C. 2,3-Dichlorobenzonitrile is hydrolysed and 2,3-dichlorobenzoic acid is chlorinated at 55-130° C. Cyano-de-halogenation of 2,3-dichlorobenzoyl chloride is carried out with a metal cyanide and alkali metal iodide by refluxing in an aprotic solvent under an inert atmosphere. 2,3-Dichlorobenzoyl cyanide is condensed with aminoguanidine bicarbonate in an organic solvent in acidic conditions using catalyst at 90-125° C. followed by insitu cyclisation of the Schiff's base by refluxing in an aliphatic alkanol with base. Crude lamotrigine is purified.
Process for preparing substituted Benzoyl Cyanide Amidinohydrazones
申请人:Chemagis Ltd.
公开号:EP1127873A3
公开(公告)日:2003-05-07
The present invention provides a process for preparing a compound of the general formula (I): wherein R1 to R5 are independently selected from hydrogen, halogen, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl or C1-6 alkoxy, all optionally substituted by one or more of halogen, hydroxy and aryl groups, as well as being independently selected from amino, mono- or disubstituted amino, alkenyloxy, acyl, acyloxy, cyano, nitro, aryl and alkylthio groups, which process comprises reacting a compound of the general formula (II): wherein R1 to R5 are as defined in formula (I), with aminoguanidine bicarbonate in a mixture of a water-soluble solvent and polyphosphoric acid.
The invention relates, in general, to an improved process for preparing lamotrigine
and related compounds. Processes for preparing and purifying lamotrigine, including lamotrigine hydrate, lamotrigine monohydrate and anhydrous lamotrigine, are described.