Triphosgene (0.224 g, 0.7 mmol) in CH2Cl2 (10 inL) at r.t. was added to a-methyl-2-nitro-4,5-dimethoxybenzyl alcohol (0.500 g, 2.2 mmol) and pyridine (0.534 inL, 6.6 mmol) in CH2Cl2 (20 mL) at −42 EC (CH3CN/CO2). After 2 hours, 4-hydroxy-3,5-diinethylbenzaldehyde (0.330 g, 2.2 mmol) and pyridine (0.534 mL, 6.6 inmol) in CH2Cl2 (10 mL) at r.t. was added and the mixture was allowed to slowly warm to r.t. overnight. The reaction mixture was quenched with saturated ammoniuin chloride (80 mL) and aqueous workup (CH2CI2, MgSO4) followed by concentration in vacuo afforded a brown solid which was recrystallized (EtOH) to yield 7k (431.9 mg, 49%) as a cream colored solid: 1H NMR (270 MHz, CDCl3) d 1.76 (d, J=6.4 Hz, 3H), 2.18 (s, 6H), 3.93 (s, 3H), 3.98 (s, 3H), 6.47 (q, J=6.4 Hz, 1H), 7.11 (s, 1H), 7.55 (s, 2H), 7.59 (s, 1H), 9.88 (s, 1H); 13C NMR (68 MHz, CDCl3) d 16.2, 22.0, 56.5, 56.6, 73.6, 107.5, 107.8, 130.4, 131.5, 132.0, 134.3, 140.1, 148.4, 151.2, 152.7, 153.8, 191.4.
