Sodium metal (0.28 g, 12.6 mmoles) is dissolved in 50 mL of freshly distilled ammonia at reflux under argon. The reaction mixture is stirred at reflux until the solution turns light gray. 4,6-Bis(1,1-dimethylethyl)-5-[(2-methoxyethoxy)-methoxy]-2-methyl-pyrimidine (3.0 g, 9.7 mmoles) is dissolved in 20 mL of tetrahydrofuran and added to the reaction. After 10 minutes, isoamyl nitrite (2.3 g, 19.3 mmoles) is added, and the reaction mixture is stirred at reflux for 2 hours. It is quenched by the addition of ammonium chloride (1.0 g, 18.7 mmoles) and the ammonia is allowed to evaporate at room temperature. The remaining oil is partitioned between 50 mL of ethyl acetate and 50 mL of water. The organic layer is washed with water (3×50 mL) and brine (50 mL), dried over magnesium sulfate, and the solvent is evaporated. The crude product is adsorbed onto a silica gel plug which is eluted with 300 mL of 5% ether in chloroform, followed by 300 mL of ether. Evaporation of the ether eluant gives 4,6-bis (1,1-dimethylethyl)-5-[(2-methoxyethoxy)methoxy]-2-pyrimidine-carboxaldehyde oxime (0.7 g, 21%) , mp 90°-97° C.
