4-Methylmorpholine → (R)-1-[[2-[2-[(R)-2-ethylcarbonyl-2,5-dihydropyrrole-1-yl]-2-oxo-ethoxyl]-phenoxy]acetyl]-2,5-dihydropyrrole-2-carboxylic acid ethyl ester

Participants

Reaction Steps

To a mixture of 0.99 g (0.003 mol) (R)-2,5-dihydro-1H-pyrrole-2-carboxylic acid ethyl ester trifluoroacetate (1:1), 0.34 g (0.0015 mol) 1,2-phenylenedioxydiacetic acid, 1.3 ml (0.012 mol) N-methylmorpholine, and 0.46 g (0.003 mol) 1-hydroxybenzotriazole hydrate in 80 ml dichloromethane were added 0.57 g (0.003 mol) 1-(3-dimethylaminopropyl)-3-ethylcarbodiimid hydrochloride. After stirring at room temperature for 18 hours the mixture was extracted with 1N HCl, water, 10% aqueous sodium bicarbonate and again water. Chromatography over silicagel with ethylacetate yielded 0.45 g (32%) (R)-1-[[2-[2-[(R)-2-ethylcarbonyl-2,5-dihydropyrrole-1-yl]-2-oxo-ethoxyl]-phenoxy]acetyl]-2,5-dihydropyrrole-2-carboxylic acid ethyl ester as colorless oil. ISP-MS: 473 (MH)+.

Provenance & Evidence