Trifluoroacetic acid → 5-[4,5-Dimethoxy-2-(1-methyl-2-phenyl-ethyl)-benzyl]-pyrimidine-2,4-diamine

Participants

Reaction Conditions

Reaction Steps

To a solution of (2,4-diamino-pyrimidin-5-yl)-[4,5-dimethoxy-2-(1-methyl-2-phenyl-ethyl)-phenyl]-methanone (0.413 g, 0.4 mmol) in 10 mL THF was added LiAlH4 (0.73 mL, 1.0 M in THF) over 5 min. After gas evolution ceased the mixture was warmed to reflux. After 3 h the mixture was cooled to 0° C. and quenched by the Fieser method. After 30 min the mixture was filtered through a pad of celite and concentrated in vacuo to give a crude white solid. To a solution of this solid in 5 mL CH2Cl2 was added trifluoroacetic acid (1.1 mL, 14.0 mmol) followed by triethylsilane (0.4 mL, 2.8 mmol). After 30 min 50 mL 10% K2CO3 was as added and the mixture was extracted with ethyl acetate and washed with brine. The combined organics were dried over Na2SO4, filtered and concentrated in vacuo. Purification via flash chromatography (95:5 CH2Cl2) afforded 5-[4,5-dimethoxy-2-(1-methyl-2-phenyl-ethyl)-benzyl]-pyrimidine-2,4-diamine (0.066 g, 58%) as a white foam; melting point (HCl salt) 227.1-227-4° C.

Provenance & Evidence