Synthesis Of Bupropion: A Round Bottom Fask (RBF)
Experimental
Synthesis of Bupropion – A round bottom flask (RBF) containing m-chloropropiophenone (1.0 g, 5.9 mmol) dissolved in 5.0 mL dichloromethane (DCM) with 0.25 mL of 1.0 M Br2 in DCM was briefly warmed to initiate the bromination reaction. Afterwards, the RBF was placed in and ice-water bath and 1.0 M Br2 in DCM (6.0 mL, 6.25 mmol) was added dropwise while stirring. DCM was removed from the reaction by rotary evaporation. Next, tert-butylamine (5.0 mL, 47.6 mmol) and 5.0 mL of N-methylpyrrolidinone (NMP) were added to the RBF, and the flask was heated in a water bath at 50-60 °C and stirred for 10 minutes. The reaction mixture was transferred to a separatory funnel along with 25 mL of H2O and extracted three times with 25-mL portions of diethyl ether. The combined ether extracts were washed with five 25- mL portions of H2O, and then dried over anhydrous K2CO3. The ether portion was then decanted into a flask and chilled in an ice-water bath. A 2:10 (v/v) mixture of concentrated hydrochloric acid and 2-propanol was added dropwise with stirring to the flask until the contents were acidic, determined with pH paper. The final product was collected by vacuum filtration, washed with diethyl ether, and dried to yield …show more content…
The spectrum integration indicates nineteen hydrogens, which is one more than the number of hydrogens present in bupropion alone. Presumably this hydrogen comes from HCl, and indeed there is a very small multiplet peak with integration equal to one hydrogen at 5.32 ppm; since the HCl hydrogen is labile and thus would most likely not show up as a clean singlet on the NMR spectrum, there is strong evidence in favor of bupropion hydrochloride as the major product. The 13C NMR spectrum is unable to show the presence of HCl since no carbon is present in the molecule, but it does agree well with what would be expected from just
Synthesis of Bupropion – A round bottom flask (RBF) containing m-chloropropiophenone (1.0 g, 5.9 mmol) dissolved in 5.0 mL dichloromethane (DCM) with 0.25 mL of 1.0 M Br2 in DCM was briefly warmed to initiate the bromination reaction. Afterwards, the RBF was placed in and ice-water bath and 1.0 M Br2 in DCM (6.0 mL, 6.25 mmol) was added dropwise while stirring. DCM was removed from the reaction by rotary evaporation. Next, tert-butylamine (5.0 mL, 47.6 mmol) and 5.0 mL of N-methylpyrrolidinone (NMP) were added to the RBF, and the flask was heated in a water bath at 50-60 °C and stirred for 10 minutes. The reaction mixture was transferred to a separatory funnel along with 25 mL of H2O and extracted three times with 25-mL portions of diethyl ether. The combined ether extracts were washed with five 25- mL portions of H2O, and then dried over anhydrous K2CO3. The ether portion was then decanted into a flask and chilled in an ice-water bath. A 2:10 (v/v) mixture of concentrated hydrochloric acid and 2-propanol was added dropwise with stirring to the flask until the contents were acidic, determined with pH paper. The final product was collected by vacuum filtration, washed with diethyl ether, and dried to yield …show more content…
The spectrum integration indicates nineteen hydrogens, which is one more than the number of hydrogens present in bupropion alone. Presumably this hydrogen comes from HCl, and indeed there is a very small multiplet peak with integration equal to one hydrogen at 5.32 ppm; since the HCl hydrogen is labile and thus would most likely not show up as a clean singlet on the NMR spectrum, there is strong evidence in favor of bupropion hydrochloride as the major product. The 13C NMR spectrum is unable to show the presence of HCl since no carbon is present in the molecule, but it does agree well with what would be expected from just