Cesium carbonate → HCID 85827663, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of the purine 8-(2,5-Dimethoxy-benzyl)-9H-purine-2,6-diamine (19.0 g, 63 mmol), 5-chloro-pent-1-yne (12.3 ml, 116 mmol), and Cs2CO3 (37.8 g, 116 mmol) in DMF (180 g) was heated to 50° C. for 16 h. Filtration and washing (2×200 ml H2O) afforded some desired product (5.8 g, 25%). The mother liquor was concentrated, diluted with EtOAc, and heated to reflux for 1 h to yield additional product (6.0 g, 26%). After cooling to room temperature, addition of 1 volume hexane to the EtOAc mother liquor gave additional product (2.6 g, 11%). Final work-up (CH2Cl2:MeOH 4:1—water) yielded additional product (5.3 g, containing 1 equivalent penty-4-yn-1-ol, 18%). Rf=0.65 in 1:10 MeOH:EtOAc. 1H NMR (DMSO-d6) δ 6.92 (d, J=8.9 Hz, 1H), 6.98 (dd, J=8.9 & 3.0 Hz, 1H), 6.59 (s, J=2.9 Hz, 1H), 6.58-6.53 (br. s, 2H), 5.72-5.68 (br. s, 2H), 4.02 (s, 2H), 3.92 (t, J=7.4 Hz, 2H), 3.73 (s, 3H), 3.62 (s, 3H), 2.84 (t, J=2.5 Hz, 1H), 2.13 (td, J=7.0 & 1.7 Hz, 2H), 1.74 (quint., J=7.3 Hz, 2H); MS 367 (M+1).

Provenance & Evidence