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), refridgerated 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. 1H-NMR (400 MHz, CD3OD, ppm): δ 0.97 (t, J=7.20 Hz, 3H), 1.65-1.77 (m, 2H), 2.48 (s, 3H), 2.74 (t, J=7.20 Hz, 2H), 3.71 (s, 3H), 5.87 (s, 1H), 5.98 (s, 2H), 6.85 (d, J=8.00 Hz, 1H), 6.96 (d, J=8.80 Hz, 1H), 7.04 (d, J=1.60 Hz, 1H), 7.07 (dd, J=1.60, 8.00 Hz, 1H), 7.58-7.61 (m, 2H). ESI-MS m/e=421 (M+).

Provenance & Evidence