p-Toluenesulfonic acid → [2S]-2-(methoxymethyl)-1-[2-(pyrid-3-yl)cyclohexylidenamino]pyrrolidine

Participants

Reaction Steps

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;

Provenance & Evidence