PMGB

To a stirred solution of the amine (0.005 mol) in 15 mL THF at 0 ^oC was added sodium hydride (60% in mineral oil, 0.0055 mol). A white solid precipitated and hydrogen gas was evolved. Chloromethyl methyl ether (0.0055 mol) (CAUTION: carcinogen) was added and the resulting mixture was stirred at room temperature for overnight (12 h). The solution turned yellow and then orange color. The reaction mixture was diluted with 50 mL ethyl acetate and 50 mL water. Some product precipitated out during extraction was filtered, washed (EtOAc) and dried under suction. The aqueous layer was extracted with dichloromethane, the organic layer was dried (Na₂SO₄) and evaporated to give the corresponding MOM ether of the amine in a total of 99% yield.   

Note: The same procedure also works in the preparation of MOM ethers of alcohols. Diisopropyl ethyl amine (DIPEA) can also be used for MOM protection of phenols: Scopton, A.; Kelly, T. R. Org. Lett. 2004, 6, 3869.