1,1,3,3-Tetramethylguanidine → (Z)-2-[[2-chloro-4-[[(3-hydroxybenzyl)amino]carbonyl]benzoyl]amino]-3-[2-(1-methylethyl)-4-methylthiazol-5-yl]propenoic acid methyl ester

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Reaction Steps

1,1,3,3-Tetramethylguanidine (55 μL, 0.44 mmol) was added to a solution of rac.-N-[2-chloro-4-[[(3-hydroxybenzyl)amino]carbonyl]benzoyl]-2-(dimethoxyphosphinyl)glycine methyl ester (Example 141; 100 mg, 0.20 mmol) in tetrahydrofuran (4 mL) at about −20° C. After 5 min, a solution of 2-(1-methylethyl)-4-methylthiazole-5-carboxaldehyde (Example 57; 38 mg, 0.225 mmol) in tetrahydrofuran (1 mL) was added. After 2 min, the cooling bath was removed and the solution was stirred at room temperature for 66 h. The solvent was evaporated and ethyl acetate (10 mL) and 10% aqueous acetic acid (5 mL) were added to the residue. The mixture was filtered to give (Z)-2-[[2-chloro-4-[[(3-hydroxybenzyl)amino]carbonyl]benzoyl]amino]-3-[2-(1-methylethyl)-4-methylthiazol-5-yl]propenoic acid methyl ester (65 mg, 62% yield) as a colorless solid.

Provenance & Evidence