1-Bromopentane → 7-Amino-1-(n-pentyl)-1,3-azaphospholo[4,5-d]pyrimidine

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Reaction Steps

7-Amino-1H-1,3-azaphospholo[4,5-d]pyrimidine (compound 10, 0.25 g, 1.64 mmol, dried by coevaporation with dry DMF, 15 mL) was suspended in dry DMF to which sodium hydride (80 mg, 2 mmol, 60% dispersion in mineral oil) was added under argon atmosphere. The mixture was stirred at room temperature for 40 min and 1-bromopentane (0.25 mL, 2 mmol) was added. The reaction was continued for 3 h and the solvent was evaporated. The residue was coevaporated with toluene (25 mL). The solid thus obtained was dissolved in a mixture of dichloromethane and methanol (1:1, 10 mL) and impregnated onto silica gel (10 g). The solvents were evaporated under reduced pressure and the dry powder was loaded on a silica gel column (2×10 cm). The column was flash eluted with dichloromethane containing 0-5% methanol to yield 0.26 g (71%) of the title compound, mp 196-198° C. Ir (KBr): ν690 (=P-C), 1220 (-P=CH), and 3110 and 3280 (NH2) cm-1. Uv (MeOH): λmax266 nm (ε23,300). 31 p nmr (DMSO-d6): δ 62.57. 1H nmr (DMSO-d6): δ 0.83(t, 3 H, CH3), 1.25 (m, 4 H, 2CH2), 1.92 (m, 2 H, CH2), 4.27 (t, 2 H, NCH2), 8.37 and 8.67 (2s, 2 H, NH2), 8.60 (d, 1 H, C5H), and 9.03 (d, 1 H, J =54 Hz, C2H). Anal. Calcd. for C10H15N4P.0.5 CH2Cl2 : C, 47.63; H, 6.09; N, 21.17. Found: C, 47.47; H, 6.09; N, 21.86.

Provenance & Evidence