Hydrochloric Acid → 2-(4-Bromo-phenyl)-propane-1,3-diamine dihydrochloride

Participants

Reaction Steps

To a stirred suspension of 2-(4-bromo-phenyl)-propane-1,3-diol (462 mg, 2.00 mmol, JACS, 125(46), 13948) in DCM (50 mL) and Et3N (0.7 mL, 5 mmol) was added MsCl (0.3 mL, 4.0 mmol) at 0° C. The resulting mixture was allowed to warm to RT and stirred for 4 h and treated with satd NaHCO3 (50 mL). The DCM layer was separated and the aq layer was extracted twice with DCM (2×20 mL). The organic layers were combined, dried (Na2SO4) and concentrated in vacuo. The resulting bismesylate was dried under high vacuum for 2 h and redissolved in DMF (5 mL) To this mixture NaN3 (0.52 g, 8.0 mmol) was added. The resulting mixture was heated at 70° C. over night. The reaction mixture was allowed to cool to RT and treated with water (10 mL). The product was then extracted with EtOAc (3×10 mL). The organic layers were combined, dried (Na2SO4) and concentrated in vacuo. The resulting diazide was dried under high vacuum for 2 h and used in next step without further purification. The diazide (280 mg, 1 mmol) was dissolved in MeOH (5 mL) and Et3N (1.4 mL, 10 mmol) and the resulting solution was placed under N2. To this solution propanedithiol (1.0 mL, 10 mmol) was added. The resulting mixture was stirred at RT overnight and concentrated to obtain a viscous oil which was dried under high vacuum for 2 h, dissolved in ether (20 mL) and treated with 2M HCl in ether (10 mL, 20 mmol). The resulting suspension was sonicated for 5 min and stirred for 5 h. The precipitate formed was collected by suction filtration and dried in vacuo to obtain 2-(4-bromo-phenyl)-propane-1,3-diamine dihydrochloride which was directly used in next step without further purification. The dihydrochloride salt (302 mg, 1 mmol) was added to a solution of Et3N (0.7 mL, 5 mmol) and dimethyl N-cyanodithioiminocarbonate (146 mg, 1.00 mmol) in EtOH (10 mL). The resulting mixture was heated at 80° C. overnight. The reaction mixture was allowed to cool to RT and stirred for another 2 h. The precipitate formed was collected by suction filtration to obtain 92 mg (33%) of the title compound. Mass spectrum (ESI, m/z): Calcd. for C11H11BrN4, 279.0 (M+H). found 279.1.

Provenance & Evidence