- AN IMPROVED PROCESS FOR THE PREPARATION OF LAMOTRIGINE
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The present invention relates to an improved process for the preparation of Lamotrigine (I) comprising a step of cyclizing 2-(2,3-Dichlorophenyl)-2-(guanidinoimino)acetonitrile(III) in the presence of an alcohol and an acid.
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Page/Page column 3; 5
(2009/07/03)
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- Process for the preparation of 6-(2,3-dichlorophenyl)-1,2,4-triazine-3,5-diamine, commonly known as lamotrigine
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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-C6aliphatic 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.
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Page/Page column 8-9
(2010/01/31)
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- Process for preparing substituted Benzoyl Cyanide Amidinohydrazones
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The present invention provides a process for preparing a compound of the general formula (I):wherein R1to R5are independently selected from hydrogen, halogen, C1-6alkyl, C2-6alkenyl, C2-6alkynyl or C1-6alkoxy, 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 R1to R5are as defined in formula (I), with aminoguanidine bicarbonate in a mixture of a water-soluble solvent and polyphosphoric acid.
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- Process for preparing substituted benzoyl cyanide amidinohydrazones
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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.
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