4-Methylmorpholine → Methanone, [4-(aminomethyl)-1-piperidinyl](2-chloro-3-pyridinyl)-

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Reaction Steps

A solution of 2-chloropyridine-3-carboxylic acid (4.09 g) and 1-methylmorpholine (2.7 ml) in dichloromethane (100 ml) was stirred at -5° C. under nitrogen and ethyl chloroformate (2.4 ml) was added dropwise. After 10 minutes a solution of N-benzylidene-1-(4-piperidyl)methylamine (5.0 g) in dichloromethane (25 ml) was added and stirring continued at -5° C. for 2 hours then at ambient temperature for 18 hours. The solvent was removed in vacuo and the residue stirred with potassium hydrogen sulphate solution (1 M; 250 ml) for 5 hours. The mixture was filtered and the filtrate washed with dichloromethane (2×150 ml), basified with aqueous sodium hydroxide solution (5 M) and extracted with dichloromethane (3×150 ml). The combined extracts were dried over magnesium sulphate and the solvent was evaporated to give 4-(aminomethyl)-1-(2-chloro-3-pyridylcarbonyl)-piperidine (4.81 g) contaminated with some 1-methylmorpholine. This material was used in the next reaction without further purification.

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