Lithium aluminum hydride → (8-Bromo-4,5-dihydro-6-oxa-3-thia-1-aza-benzo[e]azulen-2-yl)-methanol

Participants

Reaction Conditions

Reaction Steps

Lithium tetrahydroaluminate (0.363 g, 9.56 mmol) was suspended in tetrahydrofuran (30 mL) and cooled to 0° C. A solution of 8-Bromo-4,5-dihydro-6-oxa-3-thia-1-aza-benzo[e]azulene-2-carboxylic acid (1.04 g, 3.19 mmol) in tetrahydrofuran (1 mL) was then added dropwise over a 10 min period. The resulting reaction mixture was stirred while warming to r.t. for 12 h. LCMS indicated that the reaction was completely converted with a minor uncharacterized impurity present (<5%). The reaction was quenched by diluting with saturated Rochelle's salt solution and EtOAc (1:1, 200 mL). The mixture was stirred very vigorously until the phases separated. The layers were then partitioned and the aqueous layer was extracted with EtOAc (3×). The combined organic portions were dried over MgSO4, filtered and concentrated. The crude residue was purified by ISCO chromatography (40 g column, 0-75% EtOAc/heptane) to provide 0.63 g (63% yield) of (8-Bromo-4,5-dihydro-6-oxa-3-thia-1-aza-benzo[e]azulen-2-yl)-methanol. LC/MS (ESI+): m/z 313.2 (M+H).

Provenance & Evidence