Dichloromethane → Succinate

Participants

Reaction Steps

The desired solid support 8a was prepared according to reported procedures (References for succinylation: Rajeev et al., Org. Lett., 2003, 5, 3005 and for conjugation to CPG: Kumar et al., Nucleosides Nucleotides, 1996, 15, 879). A mixture of compound 7a (1.00 g, 1.39 mmol), succinic anhydride (0.17 g, 1.69 mmol, purchased from Aldrich) and DMAP (0.21 g, 1.72 mmol) were suspended in 7 mL of anhydrous ethylene dichloride for 24 h. Reaction mixture was diluted to 50 mL by adding dichloromethane and washed with dilute aqueous citric acid solution (20 mL), dried over anhydrous Na2SO4 and evaporated to dryness. The residue obtained was further dried over P2O5 under vacuum to afford an almost pure but crude monosuccinate as a white solid (1.10 g, 96.5%). The product obtained was directly used for subsequent reaction without further purification. 1H NMR (400 MHz, [D6]DMSO, 25° C.): δ 7.94-7.91 (t, J(H,H)=5.19, 5.49 Hz, 1H, exchangeable with D2O), 7.83-7.81 (d, J(H,H)=7.94 Hz, 1H, exchangeable with D2O), 7.76-7.68 (m, 3H), 7.42-7.10 (m, 12H), 6.88-6.86 (d, 4H), 4.18-4.12 (m, 2H), 4.07-3.98 (m, 2H), 3.83 (s, 3H), 3.71-3.66 (m, 7H), 3.00-2.91 (m, 4H), 2.40 (s, 4H), 2.04-2.00 (t, J(H,H)=7.32 Hz, 2H), 1.44-1.22 (m, 7H), 1.19-1.15 (m, 2H).

Provenance & Evidence