Scheme 1
From: Cleavage of pyrene-stabilized RNA bulge loops by trans-(±)-cyclohexane-1,2-diamine
Synthesis of the phosphoramidite of the PyC3 spacer. Regents and conditions: (a) p-anisaldehyde, TsOH, CH2Cl2, 12 h, 83%. (b) NaH, 1-bromomethylpyrene, THF/toluene, 48 h, 77%. (c) TsOH, MeOH/CH2Cl2, 30 h, 30%. (d) Dimethoxytrityl chloride, triethylamine, DMAP, CH2Cl2, 12 h, 65%. (e) N, N'-diisopropyl 2-cyanoethyl phosphoramidic chloride, N, N'-diisopropylethylamine, CH2Cl2, 2 h, 100%.