C[O:2][C:3]1[CH:17]=[CH:16][C:6]2[N:7]=[C:8]([N:10]3[CH2:15][CH2:14][O:13][CH2:12][CH2:11]3)[S:9][C:5]=2[CH:4]=1.Br>[Br-].C([P+](CCCC)(CCCC)CCCC)CCC.[OH-].[Na+]>[N:10]1([C:8]2[S:9][C:5]3[CH:4]=[C:3]([OH:2])[CH:17]=[CH:16][C:6]=3[N:7]=2)[CH2:11][CH2:12][O:13][CH2:14][CH2:15]1A mixture of 6-methoxy-2-morpholin-4-yl-benzothiazole (12.20 g, 48.7 mmol), tetrabutylphosphonium bromide (1.65 g, 4.87 mmol) and 48% HBr (80 mL) was stirred at 100° C. for twenty hours before it was cooled to room temperature, neutralized with 10N NaOH (60 mL) to pH=5-6. The mixture was extracted with dichloromethane. The organic layer was dried over anhydrous sodium sulfate, concentrated in vacuo to give the title compound as a white solid (10.69 g): 1H NMR (CDCl3, 200 MHz): δ=7.28 (m, 1H), 7.15 (m, 1H), 6.75 (m, 1H), 3.70 (m, 4H), 3.43 (m, 4H).
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