Reaction #2275707

Reaction equation

N-phenyltrifluoromethanesulfonamide

diisopropylethylamine

2-[(3,5-dihydroxy-pyridine-2-carbonyl)-amino]-2-methyl-propionic acid methyl ester

→

desired compound

Yield 36.0%

2-[(3-hydroxy-5-trifluoromethanesulfonyloxy-pyridine-2-carbonyl)-amino]-2-methyl-propionic acid methyl ester

Yield 36.0%

Solvents

MeOH

Conditions

Workup

1. 1
   OtherThe solvent is removed under reduced pressure
2. 2
   Otherthe crude oil which remains is purified over silica (EtOAc:heptane 1:9)

Procedure

To a solution in 2-[(3,5-dihydroxy-pyridine-2-carbonyl)-amino]-2-methyl-propionic acid methyl ester, 18, (0.312 g, 1.23 mmol) in MeOH (10 mL) containing diisopropylethylamine (0.214 mL, 1.23 mmol) at 0° C. under N2 is added N-phenyltrifluoromethanesulfonamide (0.439 g, 1.23 mmol). The reaction is warmed slowly to room temperature and stirred for 40 hours. The solvent is removed under reduced pressure and the crude oil which remains is purified over silica (EtOAc:heptane 1:9) to afford 0.170 g (36% yield) of the desired compound as a yellow oil. 1H NMR (250 MHz, MeOD) δ ppm 8.85 (1H, br s), 8.19 (1H, d, J=2.4 Hz), 7.46 (1H, d, J=2.3 Hz), 3.74 (3H, s), 1.63 (6H, s). HPLC-MS: m/z 387 [M+H]+.

Source