Diisopropylethylamine → 3-(2-amino-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-N-(3-isopropylphenyl)benzamide

Participants

Reaction Steps

A mixture of 3-(2-amino-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzoic acid (162 mg, 0.60 mmol), N,N-diisopropylethylamine (0.523 mL, 3.0 mmol), and HBTU (250 mg, 0.66 mmol) in 6.0 mL DMF was stirred at room temperature for 3 minutes, briefly warmed to approx. 50° C. to dissolve solids, stirred an additional 10 minutes at room temperature, then 3-isopropylaniline (0.127 mL, 0.90 mmol) added and the reaction heated at 65° C. After 2 hours the mixture was partitioned between EtOAc and aqueous Na2CO3 solution, the EtOAc layer washed with H2O, brine, dried with anhydrous Na2SO4 and rotary evaporated to a solid. The solid was chromatographed eluting with EtOAc/MeOH. The resulting solid was subjected to an EtOAc/NaHCO3 work-up to remove any silica gel impurity and then recrystallized from EtOAc to give the title compound as a pale yellow-beige solid (86 mg, 37%). 1H NMR (DMSO-d6) δ: 10.09 (s, 1H), 8.13 (s, 1H), 7.64-7.66 (m, 1H), 7.58-7.63 (m, 1H), 7.50-7.53 (m, 1H), 7.32-7.40 (m, 2H), 7.18-7.29 (m, 2H), 6.96-7.01 (m, 1H), 6.41 (s, 2H), 4.29 (s, 2H), 3.65 (t, J=6.0 Hz, 2H), 2.88 (spt, J=7.0 Hz, 1H), 2.77 (t, J=5.9 Hz, 2H), 1.22 (d, J=7.0 Hz, 6H).

Provenance & Evidence