[CH3:1][NH:2]/[C:3](/[NH:8][CH2:9][CH2:10][S:11][CH2:12][C:13]1[O:17][C:16]([CH2:18][N:19]([CH3:21])[CH3:20])=[CH:15][CH:14]=1)=[CH:4]\[N+:5]([O-:7])=[O:6].[ClH:22]>C(O)(C)C>[CH3:1][NH:2][C:3]([NH:8][CH2:9][CH2:10][S:11][CH2:12][C:13]1[O:17][C:16]([CH2:18][N:19]([CH3:20])[CH3:21])=[CH:15][CH:14]=1)=[CH:4][N+:5]([O-:7])=[O:6].[ClH:22]Ranitidine base (31.44 g, 0.1 mol) was dissolved in anhydrous isopropyl alcohol (isopropanol) (160 mL) by warming to 30° C., filtering through celite and washing the cake with anhydrous isopropyl alcohol (68 mL). The solution was warmed to 43° C., seeds (Form #1, 0.2 g) were added and anhydrous hydrogen chloride in anhydrous isopropyl alcohol (15.19 g, 24%, 1 equivalent) was added all at once. The temperature rose to 51° C. and the temperature was maintained at 45°-50° C. for 5 hours while the product crystallized. The mixture was allowed to cool to 25° C. The precipitate was filtered and washed with anhydrous isopropyl alcohol (2×30 mL) to yield damp Ranitidine Hydrochloride. Vacuum drying at 40° C. overnight yields 34.26 g (0.0977 mol, 97.7%) of pure Ranitidine Hydrochloride (Form #1). The I. R. in KBr of the crystals conformed to Form #1.
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