Cesium carbonate → HCID 68313011, compound

Participants

Reaction Steps

To a suspension of 2-(2-isopropyl-5-methyl-2H-[1,2,4]triazol-3-yl)-4,5-dihydro-6-oxa-1,3a-diazabenzo[e]azulen-8-ol from Example 4 (330 mg, 1.013 mmol) in CH3CN (18 mL) was added Cs2CO3 (825 mg, 2.53 mmol) followed by a solution of 2-bromo-4-methylpentanedioic acid diethyl ester (640 mg, 2.276 mmol) in CH3CN (2 mL) and stirring at reflux temperature was continued for 1.5 h. After cooling to RT, the reaction mixture was partitioned between water and EtOAc. The aqueous phase was extracted with EtOAc and the combined organic layers were washed with water, followed by brine, then dried (Na2SO4) and concentrated in vacuo. The resulting residue was purified by column chromatography (Si-PCC, gradient 2-8% MeOH in DCM) affording 2-[2-(2-Isopropyl-5-methyl-2H-[1,2,4]triazol-3-yl)-4,5-dihydro-6-oxa-1,3a-diazabenzo[e]azulen-8-yloxy]-4-methylpentanedioic acid diethyl ester as a pale yellow gum (391 mg, 73%). LCMS: RT 3.59 min [M+H]+ 526.5

Provenance & Evidence