1,1,3,3-Tetramethylguanidine → Rac.-(z)-2-[[2-chloro-4-[1-hydroxy-3-(3-hydroxyphenyl)propan-1-yl]benzoyl]amino]-3-(quinolin-3-yl)propenoic acid methyl ester

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Reaction Steps

1,1,3,3-Tetramethylguanidine (60 μL, 0.48 mmol) was added to a solution of rac.-N-[2-chloro-4-[1-hydroxy-3-(3-hydroxyphenyl)propan-1-yl]benzoyl]-2-(dimethoxyphosphinyl)glycine methyl ester (Example 134; 120 mg, 0.24 mmol) in tetrahydrofuran (5 mL) at −20° C. After 10 min, quinoline-3-carboxaldehyde (39.3 mg, 0.25 mmol) was added and the solution was stirred at room temperature for 16 h. The solvent was evaporated and ethyl acetate (10 mL) was added. The solution was washed with saturated sodium bicarbonate solution (5 mL) and the aqueous layer was extracted with ethyl acetate. The combined organic layers were dried (MgSO4), filtered, evaporated and chromatographed over silica gel (50% ethyl acetate/hexanes) to give rac.-(Z)-2-[[2-chloro-4-[1-hydroxy-3-(3-hydroxyphenyl)propan-1-yl]benzoyl]amino]-3-(quinolin-3-yl)propenoic acid methyl ester (93 mg, 75% yield) as an off-white solid.

Provenance & Evidence