To a suspension of LiAlH4 (85 mg, 2.23 mmol) in THF (1 mL) at 0° C. was added a solution of 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 (391 mg, 0.744 mmol) in THF (20 mL) and stirring at RT was continued for 2.5 h. To the reaction mixture was added EtOAc (2 mL) and stirring was continued for 30 min. An aqueous solution (10%) of Rochelle's salt was then added and the mixture was stirred for 5 min. Organic solvents were removed under reduced pressure and the resulting aqueous phase was extracted with EtOAc (×2). The combined organic phases 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 3-18% 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-methylpentane-1,5-diol as a colorless gum (181 mg, 55%). LCMS: RT 2.49 min [M+H]+ 442.3
