Sulfur Dioxide → HCID 19434071, compound

Participants

Reaction Steps

To a solution of the product from Example 18, Step D (4.81 g, 14.89 mmol) in anhydrous THF (80 mL) under nitrogen at -70° C. was added n-butyllithium (2.5M, 14.89 mL, 37.22 mmol) over 5 min. After stirring for 1 h, a stream of sulfur dioxide was passed over the surface of the reaction mixture for about 5 min. The mixture was warmed to ambient temperature and evaporated to a residue which was mixed with methylene chloride (250 mL). This suspension was cooled on an ice bath and N-chlorosuccinimide (6.96 g, 52.1 mmol) was added. The reaction mixture was stirred at ambient temperature for 2 h and t-butylamine (15 mL, 143 mmol) was added; the mixture was evaporated to dryness after 16 h. The residue was mixed with a saturated aqueous solution of sodium bicarbonate (200 mL) and extracted with ethyl acetate (2×200 mL). The combined extracts were dried (MgSO4) and evaporated to give a residue which was purified by column chromatography (silica, 40% ethyl acetate/hexane) to give an oil (4.41 g, 62%):

Provenance & Evidence