n-Butyl lithium → 8-(1-(1-((Tert-butyldimethylsilyl)oxy)-4-methyl-1,3-dihydroisobenzofuran-5-yl)-1-hydroxy-2-methylpropan-2-yl)-2,8-diazaspiro[4.5]decan-1-one

Participants

Reaction Conditions

Reaction Steps

To a solution of ((5-bromo-4-methyl-1,3-dihydroisobenzofuran-1-yl)oxy)(tert-butyl)dimethylsilan (3.9 g, 11.36 mmol) in tetrahydrofuran (50 ml) at −78° C. was added N-butyllithium (5.00 ml, 12.50 mmol). After 15 min, 2-methyl-2-(1-oxo-2,8-diazaspiro[4.5]decan-8-yl)propanal (0.892 g, 3.98 mmol) was added in one portion. The resulting solution was stirred at −78° C. for 3.5 h before being quenched by addition of methanol (6 mL) and saturated sodium bicarbonate (100 mL). The mixture was extracted with 30% isopropanol/methylene chloride (3×100 mL). The combined organic phase was dried over sodium sulfate, concentrated and the residue was purified on silica gel using methanol/methylene chloride to give the title compound. LC/MS: (M+1)+: 489.15.

Provenance & Evidence