Does anyone know the rest of this recipe? It's a famous synthetic route, I'm needing the end of it, the part of the hofmann rearrangement using TCCA to form the MDA. Thank you.
follow below:
100g
Helional (100g ~92ml)
Hydroxylamine HCl (36.93g)
DMSO (500ml)
NaOH (21g)
H2O2 30% soln (ph 7.5-7.
(600ml)
Helional mass: 192.21g/mol
Hydroxylamine.HCl mass: 69.49g/mol
Aldehyde (.52mol, 100g) was added to a solution of Hydroxylamine HCl (.53mol, 36.93g) in DMSO (500ml). This solution was then heated for 90 minutes at 85-90* over hot/boiling water with vigorous stirring [make sure RBF is open top]. Upon removal of heat, the solution was allowed to stand on a stirrer until the temp reached ~80*, and aqueous NaOH added** until a pH of 10 was reached (addition of NaOH solution causes smoke, and darkening of solution. Sharp change in pH noted). [optional: 6g of bicarb soda was added to aid as a pH buffer]. Then at 70*+, 500-600ml of neutralized 30% H2O2 was added dropwise through an addition funnel, maintaining the temperature under 95*, and monitoring the pH to keep it between 9-10 (add 10% NaOH solution if required ) . Upon completion of the addition, the reaction was allowed to stir until gas evolution and exothermia had ceased. The resulting light yellow solution is poured into a pyrex dish at around 50*, and put in a 0* fridge and allowed to sit overnight. The resulting crystals vacuum filtered and washed with water. Yield quantitative. (Should have sparkling white amide crystals maybe with hints of yellow which should come off in a water wash).
Reasons for low yields can be overheating your Hydroxylamine/DMSO (anything over 100* will begin to cause yellow impure amide/lower yields), and not adding enough H2O2 in the correct pH range.
follow below:
100g
Helional (100g ~92ml)
Hydroxylamine HCl (36.93g)
DMSO (500ml)
NaOH (21g)
H2O2 30% soln (ph 7.5-7.
Helional mass: 192.21g/mol
Hydroxylamine.HCl mass: 69.49g/mol
Aldehyde (.52mol, 100g) was added to a solution of Hydroxylamine HCl (.53mol, 36.93g) in DMSO (500ml). This solution was then heated for 90 minutes at 85-90* over hot/boiling water with vigorous stirring [make sure RBF is open top]. Upon removal of heat, the solution was allowed to stand on a stirrer until the temp reached ~80*, and aqueous NaOH added** until a pH of 10 was reached (addition of NaOH solution causes smoke, and darkening of solution. Sharp change in pH noted). [optional: 6g of bicarb soda was added to aid as a pH buffer]. Then at 70*+, 500-600ml of neutralized 30% H2O2 was added dropwise through an addition funnel, maintaining the temperature under 95*, and monitoring the pH to keep it between 9-10 (add 10% NaOH solution if required ) . Upon completion of the addition, the reaction was allowed to stir until gas evolution and exothermia had ceased. The resulting light yellow solution is poured into a pyrex dish at around 50*, and put in a 0* fridge and allowed to sit overnight. The resulting crystals vacuum filtered and washed with water. Yield quantitative. (Should have sparkling white amide crystals maybe with hints of yellow which should come off in a water wash).
Reasons for low yields can be overheating your Hydroxylamine/DMSO (anything over 100* will begin to cause yellow impure amide/lower yields), and not adding enough H2O2 in the correct pH range.
