100 ml of acetone then 30 ml of acetone containing 0 4 g of sulfuric acid was added the obtained mixture was stirred and white crystals were precipitated from the reaction solution the resulting precipitate was collected by filtration washed with acetone and then dried at 60 u00b0 c in vacuum for 3 hours to obtain 1 2 g of ivabradine sulfate melting point was determined by capillary crystalline approach at 156 u02dc 158 u00b0 c water content is 0 8 the ph of the ivabradine sulfate aqueous is about 1 8 c 1 yield 55 5 it is form i crystal of ivabradine sulfate judged by x ray and dsc patterns 2 0 g of the form i crystal of ivabradine sulfate prepared by example 1 was dissolved in 50 ml of methanol the solvent was concentrated in vacuum to dryness and 65 ml of acetone was added the mixture was heated in water bath to dissolve and then stirred to precipitate the white crystals after cooling to room temperature the resulting precipitate was collected by filtration washed by acetone and then dried at 60 u00b0 c in vacuum for 3 hours to obtain 1 82 g of ivabradine sulfate water content is 0 7 yield 91 0 it is form i crystal of ivabradine sulfate judged by x ray and dsc patterns the data of stability test was shown in table 1 2 0 g of the form i crystal of ivabradine sulfate prepared by example 1 was dissolved in 50 ml of methanol the solvent was concentrated in vacuum to dryness and 25 ml of ethanol was added the mixture was heated in water bath to dissolve and then stirred to precipitate the white crystals after cooling to room temperature the resulting precipitate.