Reaction #6007

Reaction equation

2-(pyrid-3-yl)cyclohexanone

[S]-(-)-1-amino-2-(methoxymethyl)pyrrolidine

p-toluenesulphonic acid

→

[2S]-2-(methoxymethyl)-1-[2-(pyrid-3-yl)cyclohexylidenamino]pyrrolidine

Solvents

toluene

diethyl ether

Conditions

Workup

1. 1
   OtherThe toluene was removed in vacuo
2. 2
   Otherto afford an oil which
3. 3
   Washwashed with aqueous saturated sodium bicarbonate solution (2×170 ml)
4. 4
   DryingThe organic phase was dried over magnesium sulphate
5. 5
   Filtrationthen filtered
6. 6
   Concentrationconcentrated in vacuo

Procedure

A mixture of 2-(pyrid-3-yl)cyclohexanone (20.6 g, 117.6 mmol), [S]-(-)-1-amino-2-(methoxymethyl)pyrrolidine (`SAMP`) (15.4 g, 118 mmol) and p-toluenesulphonic acid (316 mg) was refluxed in toluene (475 ml) for 4 hours. The toluene was removed in vacuo to afford an oil which was dissolved in diethyl ether (340ml) and washed with aqueous saturated sodium bicarbonate solution (2×170 ml). The organic phase was dried over magnesium sulphate then filtered and concentrated in vacuo to afford [2S]-2-(methoxymethyl)-1-[2-(pyrid-3-yl)cyclohexylidenamino]pyrrolidine (30.8 g, 113 mmol) as a 50:50 mixture of diastereoisomers;

Source