Dimethylamine → Methyl 10-(dimethylamino)-10-oxodecanoate

To a solution of the decandioic acid mono methyl ester (2 mmol) in dry tetrahydrofuran (20 ml) was added 1-hydroxybenzotriazole (1 mmol), N,N′-dicyclohexylcarbodiimide (1.1 mmol) and N,N-dimethylamine (2M solution in tetrahydrofuran, 2 ml). The mixture was stirred overnight and then filtered. The solvent was removed in vacuo and the residue redissolved in ethyl acetate. The ethyl acetate solution was washed sequentially with saturated sodium hydrogen carbonate solution, 1M potassium hydrogen sulphate solution and saturated sodium chloride solution. After drying over anhydrous magnesium sulphate and removal of the solvent, the product was purified by preparative layer chromatography on silica plates in ethyl acetate to afford methyl 9-(N,N-dimethylcarbamoyl)nonanoate.