反应详情

温度

0 °C

To a solution of the title B compound in Example 9, 2-(2,4-dimethoxybenzyl)-1,1-dioxo-1,2,5-thiadiazolidin-3-one (2.0 g, 7.0 mmol) and 4-hydroxymethyl-benzoic acid benzyl ester (2.54 g, 10.5 mmol) in THF (50 mL) is added triphenylphosphine (3.67 g, 14 mmol) and the mixture is stirred until dissolved. The reaction is cooled to 0° C. and diethyl azodicarboxylate (2.20 mL, 14 mmol) dissolved in THF (20 mL) is added dropwise. The reaction is stirred for 16 h, while allowing to warm to RT, then concentrated. The residue is taken up in CH2Cl2, and chromatographed in two portions on a 110 g silica gel RediSep column (Isco, Inc.) with a 30 mL/min gradient elution of 0:100 (EtOAc:hexane) to 5:95 over 10 min. Fractions containing product are combined and concentrated to yield 4-[5-(2,4-dimethoxy-benzyl)-1,1,4-trioxo-1,2,5-thiadiazolidin-2-ylmethyl]-benzoic acid benzyl ester as a white solid.

1. dissolutionuntil dissolved
2. additionis added dropwise
3. stirringThe reaction is stirred for 16 h
4. temperatureto warm to RT
5. concentrationconcentrated
6. customchromatographed in two portions on a 110 g silica gel RediSep column (Isco, Inc.) with a 30 mL/min gradient elution of 0:100 (EtOAc:hexane) to 5:95 over 10 min
7. additionFractions containing product
8. concentrationconcentrated