1260774-44-4Relevant articles and documents
PROCESS FOR PREPARING LEVOSIMENDAN AND INTERMEDIATES FOR USE IN THE PROCESS
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Page/Page column 11, (2011/02/24)
In an embodiment, the present invention provides a process for preparing (-)-6-(4- aminophenyl)-5-methylpyridazin-3-(2H)-one, which process comprises: a) reacting racemic 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3-(2H)-pyridazinone of formula (Il) with a chiral tartaric acid derivative to obtain a diastereomeric salt of (-)-6-(4- aminophenyl)-4,5-dihydro-5-methyl-3-(2H)-pyridazinone and the chiral tartaric acid derivative; and b) reacting the diastereomeric salt with a base to obtain (-)-6-(4- aminophenyl)-4,5-dihydro-5-methyl-3-(2H)-pyridazinone. The (-)-6-(4-aminophenyl)-4,5- dihydro-5-methyl-3-(2H)-pyridazinone may be used to prepare levosimendan.