Diisopropylamine → HCID 131730229, compound

Participants

Reaction Steps

n-Butyllithium (2.5 M in hexanes, 1.6 mL, 4 mmol) was added to a solution of diisopropylamine (0.56 mL, 4 mmol) in 5 mL of tetrahydrofuran at −78° C. After 30 minutes, ethyl trimethylsilylacetate (0.73 mL, 4 mmol) was added. After stirring 30 minutes, a solution of the compound of Example 16J (787 mg, 2 mmol) in 8 mL of tetrahydrofuran was added, followed by a rinse of 2 mL of tetrahydrofuran. After 2 hours, the reaction was quenched by the addition of 10 mL of saturated aqueous NH4Cl. After warming to ambient temperature, the mixture was poured into 100 mL of 20% NaCl, then extracted twice with 100 mL of tert-butyl methyl ether. The combined tert-butyl methyl ether extracts were dried over MgSO4, filtered and concentrated in vacuo. The residue was purified by silica gel chromatography (300 mL of SiO2, elution with a gradient of 1:1 dichloromethane:hexanes to dichloromethane) to afford 538 mg (58% yield) of a ˜4:1 mixture of isomers favoring the title compound (538 mg, 58%).

Provenance & Evidence