Triphenylphosphine → Purine

Participants

Reaction Conditions

Reaction Steps

To the dried resin (0.29 mmol) was added a homogeneous suspension of 6-chloro-2-fluoro-9H-purine (0.50 g, 2.9 mmol) and triphenylphosphine (0.38 g, 1.44 mmol) in 1.75 mL of THF. The RV was cooled to 0° C. (Julabo chiller) and then added, under an atmosphere of N2, 2.0 mL (1.44 mmol) of a 0.72M solution of DEAD (diethyl azodicarboxylate) in THF. The resin mixture was warmed, while agitating, to ambient temperature over 1.5 h and then agitated for an additional 22 h, upon which the RV was drained and the resin washed successively with THF (5×5.0 mL), DMA (5×5.0 mL), CH2Cl2 (5×5.0 mL), Et2O (2×5.0 mL), CH2Cl2 (1×5.0 mL), Et2O (1×5.0 mL), and CH2Cl2 (2×5.0 mL). Excess solvent was removed via N2 flow overnight to provide the purine resin 1b. The following analytical data was obtained upon cleavage of 1b (3–5 mg) with 30% TFA/CH2Cl2 (˜5 min): 65% HPLC purity, ˜5:1 major/minor peaks (no apparent 3-hydroxyphenethyl alcohol HPLC peak).

Provenance & Evidence