Toluene → 8-chloro-7H-purin-6-amine

Participants

Reaction Steps

To a solution of adenosine (2.67 g, 10 mmol) in DMA/HCl (0.5M, 45 mL) was added m-chloroperoxybenzoic acid (MCPBA, 3.22 g, 16 mmol 87%) and stirred at room temperature for 2.5 h. An additional portion of MCPBA (0.9 g, 5 mmol) was added and stirring continued for another 1 h. Toluene (50 mL) was added to the reaction mixture and the solvents evaporated at 60° C. under vacuo to dryness. The residue was dissolved in water (50 mL) and extracted with ether (3×50 mL). The pH of the aqueous phase was adjusted to 5 with 2N NaOH and then diluted with EtOH (100 mL). The solution was stored in the refrigerator overnight. The light yellow solid that separated was collected, washed with cold EtOH (2×25 mL) and dried to give 1.44 g (85.2%) of 1: mp 305°-310° C. (dec.) [Lit. mp>300° C. (dec.)]: IR (KBr): 630 (C-C1), 3100-3300 (NH2) cm-1 : UV: λmax (pH 1) 262 nm (ε 8,700): λmax (pH 7) 268 nm (ε 7,900): λmax (pH 11) 269 nm (ε 8,300): 1H NMR (Me2SO-d6): δ 7.48 (br s, 2, NH2), 8.10 (s, 1, C2H) and 13.60 (br s, 1, N9H).

Provenance & Evidence