Sodium hydride → (S)-2-[4-(3,4-Dichloro-benzyloxy)-phenyl]-2,3-dihydro-benzo[1,4]dioxine-6-carbonitrile

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Reaction Steps

3-{(S)-2-[4-(3,4-Dichloro-benzyloxy)-phenyl]-2-hydroxy-ethoxy}-4-fluoro-benzonitrile (28.9 g) was dissolved in 30 mL dry NMP and 270 mL dry diglyme under nitrogen and heated to 142° C. internal temperature. A suspension of sodium hydride (2.676 g of 60% NaH in mineral oil) in 6 mL of dry NMP and 54 mL of dry diglyme was added all at once via cannula while stirring. After 15 min the reaction was removed from heating and cooled 5 min, then poured into ice/1 L EtOAc/0.5 L 1 N HCl. The layers were separated and the organic layer washed twice with water, once with brine and dried over Na2SO4. The residue was purified by silica gel flash chromatography (DCM to 1:1 DCM/EtOAc) to provide 31 g of partially purified solid which was then crystallized from refluxing 3:1 MeOH/DCM, to give 15 g of desired product. 1H NMR (400 MHz, CDCl3): 7.54 (d, 1H), 7.46 (d, 1H), 7.33 (m, 2H), 7.28-7.24 (m, 1H), 7.23 (d, 1H) 7.19 (m, 1H), 7.0 (m, 3H), 5.12 (m, 1H), 5.04 (s, 2H), 4.37 (m, 1H), 4.03 (m, 1H).

Provenance & Evidence