Water → HCID 58371984, compound

Participants

Reaction Conditions

Reaction Steps

To a suspension of NaH (52 g, 1.3 mol) in 2.2 L of anhydrous DMF at 8° C., was added a solution of 3-Hydroxy-pyrrolidine-1,3-dicarboxylic acid 1-benzyl ester 3-methyl ester 3a (278 g, 1.0 mol) in 700 DMF, keeping the reaction temperature below 11° C. After complete addition (˜20 min), ice bath was removed, stirred at 16-18° C. for 1 h, and then at ambient temperature for 1 h. Cooled back to 15° C., added MeI (81 mL, 1.3 mol) slowly. Reaction mixture was stirred at ambient temperature for 1 overnight. The reaction mixture was then poured in a cold water (4 L) and then extracted with Et2O (6 L) and EtOAc (2 L), washed the organic later with water (5 L), brine (700 mL), dried over magnesium sulfate, filtered and evaporated to give crude 3-Methoxy-pyrrolidine-1,3-dicarboxylic acid 1-benzyl ester 3-methyl ester 4a 289 g (99% crude yield, contains mineral oil) (stirring/separation with pentane wash gave 4a, 268.2 g (92%).

Provenance & Evidence