Methanol → Methyl alpha-(2-n-propyl-4-methylaminosulfonylphenoxy)-3,4-methylenedioxyphenylacetate

Participants

Reaction Steps

To a solution of 2.19 g (5.38 mmol) of the product of Step C dissolved in 20 mL of anhydrous THF was added 2.41 mL (16.1 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene and the reaction mixture was magnetically stirred under a nitrogen atmosphere for 25 minutes at room temperature. Iodomethane (1.00 mL; 16.1 mmol) was added and the reaction mixture was stirred an additional 15 hours at room temperature. The reaction mixture was diluted with EtOAc and a precipitate formed which was redissolved by addition of methanol. The mixture was further diluted with warm EtOAc (150 mL total), refrigerated overnight and a solid separated which was removed by filtration. The filtrate was evaporated in vacuo and the residue was purified on a silica gel flash chromatography column eluted with 5% EtOAc--CHCl3. Combination of the purified fractions and evaporation in vacuo afforded 0.164 g of the title compound and a number of impure fractions which were reserved for repurification.

Provenance & Evidence