Dimethylformamide → 3-butyl-1-methyl-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purine-8-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

A pre-dried flask was charged with 3-butyl-1-methyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (300 mg, 1.14 mmol) and anhydrous THF (6 ml), cooled to −75° C. under nitrogen, then treated with LiHMDS (1.37 ml of a 1.0M solution in THF). The resulting solution was allowed to warm to −60° C. over 1.5 hours before the addition of anhydrous DMF (177 ul, 2.29 mmol). The solution was allowed to warm to −10° C. over 3 hours then it was quenched with sat. NH4Cl (aq) solution. The mixture was partitioned between 1M HCl (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated giving a brown oil (350 mg). The product was purified by SPE (Si, 10 g) eluting with EtOAc/cyclohexane mixtures to give the title compound as a white solid (131 mg, 39%); NMR; δH (400 MHz, d6-DMSO) 0.91 (t, 3H, J=7.5 Hz), 1.28-1.39 (m, 2H), 1.63-1.73 (m, 2H), 3.25 (s, 3H), 4.02 (t, 2H, J=7.5 Hz), 5.03 (dd, 1H, J=17 and 1 Hz), 5.17 (dd, 1H, J=10 and 1 Hz), 5.31 (app. d, 2H, J=5.5 Hz), 5.98-6.09 (m, 1H), 9.88 (s, 1H).

Provenance & Evidence