Czech Patent 238 234 - apologies if the translation is off. It may still be useful for some to try as a simpler method of thermal rearragement.
Process for the preparation of 2- (2-chlorophenyl) -2-methylamino hydroxy cyclohexanone by thermal rearrangement of methylimine hydrochloride 2-hydroxycyclopentyl- (2-chlorophenyl) ketone at 185-190, characterized by the fact that to dissolve the substance before the precision anhydrous ethylene glycol.
The rearrangement was performed in a solvent, i.e. in a homogeneous one environment, the substance is heated to the required temperature while stirring in solution, ie quickly. This way obtains the desired substance in a yield of 75% and good quality.
Process for the preparation of 2- (2-chlorophenyl) -2-methylamino hydroxy cyclohexanone by thermal rearrangement of methylimine hydrochloride 2-hydroxycyclopentyl- (2-chlorophenyl) ketone at 185-190, characterized by the fact that to dissolve the substance before the precision anhydrous ethylene glycol.
The rearrangement was performed in a solvent, i.e. in a homogeneous one environment, the substance is heated to the required temperature while stirring in solution, ie quickly. This way obtains the desired substance in a yield of 75% and good quality.
- To 2000g of methylimine hydrochloride 1-hydroxycyclopentyl-2-chlorophenyl / ketone is added to a 6 L sulfonation flask of 2000 ml anhydrous ethylene glycol. Then the oil bath is heated to temperature of 190c and the 6 L flask is immersed in this bath and the contents begin to mix.
- The solution in the flask was stirred at 190% bath for 50 min. Then The stirring is interrupted and the flask is picked up from the bath. Raw hydro-chloride 2- (2-chlorophenyl-2-methylaminocyclohexanone is excluded. after cooling from the reaction mixture in the form of a crystalline substance. The yield of the process is 1500g, i.e. 75% th.