N-Iodosuccinimide → 7-iodo-2,4-bis-benzyloxy-5H-pyrrolo[3,2-d]pyrimidine

Participants

Reaction Steps

To a stirred solution of 2,4-bis-O-benzyl-5H-pyrrolo[3,2-d]pyrimidine 15 (1.43 g, 4.3 mmol) in anhydrous CH2Cl2 (15 mL) under N2, NIS (1.069 g, 4.7 mmol) was added at which point the reaction mixture turned from pink to orange. The mixture was stirred overnight until the TLC indicated the absence of starting material. The reaction mixture was washed with aqueous Na2S2O3 (15 mL) followed by brine (15 mL). The organic layer was dried over MgSO4, loaded onto silica and purified using column chromatography eluting with 4:1 then 1:1 hexanes/EtOAc to obtain compound 16 as a pale-yellow solid (1.77 g, 3.88 mmol, 90%). Rf 0.4 in 1:3 hexanes/EtOAc. Mp 157.8-158.4° C. 1H NMR (400 MHz, CDCl3): δ 5.53 (s, 4H), 7.32-7.41 (m, 9H), 7.55-7.57 (m, 2H), 8.71 (br s, 1H, NH). 13C NMR: 57.3, 68.7, 69.3, 111.9, 127.9, 128.3, 128.6, 128.66, 128.7, 128.9, 132.4, 135.8, 137.2, 152.0, 156.9, 160.1. FAB-MS m/z for C20H16IN3O2 calculated [M+H]+ 458.0360. found 458.0357.

Provenance & Evidence