Imidazole → HCID 11608114, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-N,9-bistritylguanine (1.90 g, 3 mmol), I2 (3.88 g, 15 mmol), Ph3P (3.99 g, 15 mmol) and imidazole (1.10 g, 15 mmol) was stirred in toluene (150 mL) at 95° C. for 15 min, and DIPEA (2.9 mL, 2.15 g, 16.6 mmol) was added. The mixture was stirred at 95° C. overnight. After removal of volatiles, the residue was boiled with EtOAc (3×) and filtered hot. The combined EtOAc extracts were evaporated to dryness. The residue was dissolved in TFA/H2O (9:1, 60 mL), and the solution was stirred at 0° C. for 4 h. Volatiles were evaporated in vacuo, and the residue was dissolved in 0.1 N NaOH/H2O//CH2Cl2 (100 mL/100 mL). The organic layer was extracted with 0.1 N NaOH/H2O (50 mL×2), and the aqueous phase was combined, washed [CH2Cl2 (2×50 mL)], and neutralized with CO2. Volatiles were evaporated in vacuo, and the residue was washed (H2O, CH2Cl2) to give 2-amino-6-(imidazol-1-yl)purine (0.40 g, 69%): UV (MeOH) max 222, 320 nm (∈ 29 800, 8700), min 207, 280 nm (∈ 16 100, 1500); 1H NMR (500 MHz, DMSO-d6) δ 12.89 (s, 1H), 8.94 (s, 1H), 8.25 (s, 1H), 8.16 (s, 1H), 7.18 (s, 1H), 6.67 (s, 2H); 13C NMR (125 MHz, DMSO-d6) δ 160.7, 157.5, 145.4, 141.9, 137.2, 130.5, 117.7, 115.4; HRMS m/z 201.0753 (M+[C8H7N7]=201.0763).

Provenance & Evidence