Diisopropylethylamine → 2-{4-[5-(2-Diethylamino-6-methyl-pyrimidin-4-yl)-[1,2,4]oxadiazol-3-yl]-phenyl}-ethanol

Participants

Reaction Steps

To a suspension of 2-diethylamino-6-methylpyrimidine-4-carboxylic acid (1.31 g, 6.28 mmol) in DMF (20 mL) is added DIPEA (3.23 mL, 18.8 mmol) followed by TBTU (2.62 g, 8.17 mmol). The mixture is stirred at rt for 10 min before N-hydroxy-4-(2-hydroxy-ethyl)-benzamidine (1.24 g, 6.91 mmol) is added. After stirring for 1 h, the reaction mixture is diluted with EtOAc and the solution is washed with sat. aq. NaHCO3. The aq. phase is extracted with EtOAc and the combined org. extracts are dried over MgSO4, filtered and concentrated to give the crude hydroxyamidine ester intermediate (3.56 g). This material is dissolved in dioxane (50 mL) and the resulting solution is stirred at 85° C. for 16 h. The solvent is evaporated and the crude product is purified by CC (eluting with EtOAc/Heptane 1:4) to give 2-{4-[5-(2-diethylamino-6-methyl-pyrimidin-4-yl)-[1,2,4]oxadiazol-3-yl]-phenyl}-ethanol as a yellow solid (1.30 g); LC-MS: tR=1.07 min; [M+H]+=354.07. 1H NMR (CDCl3): δ 1.25 (t, J=7.0 Hz, 6H), 1.45 (m, 1H), 2.47 (s, 3H), 2.98 (t, J=6.5 Hz, 2H), 3.75 (q, J=7.0 Hz, 4H), 3.95 (m, 2H), 7.23 (s, 1H), 7.41 (d, J=7.8 Hz, 2H), 8.15 (d, J=7.5 Hz, 2H).

Provenance & Evidence