Methanol → (R)-((S)-2-(3,5-dichloropyridin-4-yl)-1-(3,4-dimethoxyphenyl)ethyl) 2-(6-methoxynaphthalen-2-yl)propanoate

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Reaction Steps

((S)-2-(3,5-dichloropyridin-4-yl)-1-(3,4-dimethoxyphenyl)ethyl) 2-(6-methoxynaphthalen-2-yl)propanoate (diastereoisomeric mixture prepared as described in Ex 1, Step 1, 79 g, 146 mmol) was dissolved in CHCl3 (100 ml), and MeOH (30 ml) was slowly added up to persistent opalescence and the mixture left at RT for 2 hours. The solid formed was collected by filtration and re-crystallized by CHCl3/MeOH (70 ml/20 ml) solvent system to obtain 35 g of the desired compound (yield 88%, ee 98%). Chiral HPLC analysis Rt=42.33 min; eluent:hexane:isopropanol 97:3; 1H NMR (600 MHz, CHLOROFORM-d) δ ppm 8.04 (s, 2H), 7.67 (d, J=8.79 Hz, 1H), 7.58 (d, J=8.52 Hz, 1H), 7.53 (m, 1H), 7.12-7.20 (m, 3H), 6.95 (dd, J=8.24, 1.92 Hz, 1H), 6.78-6.88 (m, 2H), 6.14 (dd, J=10.44, 4.12 Hz, 1H), 3.95 (s, 3H), 3.88 (s, 3H), 3.78-3.81 (m, 4H), 3.55 (dd, J=13.73, 10.44 Hz, 1H), 3.14 (dd, J=13.60, 4.26 Hz, 1H), 1.44 (d, J=7.14 Hz, 3H).

Provenance & Evidence