To a solution of N4-(1-ethyl-propyl)-6-methyl-2-(2,4,6-trimethyl-phenoxy)-pyridine-3,4-diamine (0.250 g, 0.763 mmol) in dry THF (6 ml) was treated with 1M LiN(SiMe3)2 in THF (1.0 ml, 1.0 mmol) at −78° C. and stirred for 10 min. an excess of methyl iodide was added and the resulting mixture was stirred at room temperature overnight. The mixture was quenched with water and extracted with ethyl acetate. The organic layer was dried and concentrated to give a crude material. The crude material was purified through silica gel column chromatography using 5% ethyl acetate in hexane as eluent to give N4-(1-ethyl-propyl)-6,N3,N3-trimethyl-2,4,6-trimethyl-phenoxy)-pyridine-3,4-diamine and N4-(1-ethyl-propyl)-6,N3-dimethyl-2-(2,4,6-trimethyl-phenoxy)-pyridine-3,4-diamine.
