m-Chloroperbenzoic acid → HCID 71293128, compound

Participants

Reaction Conditions

Reaction Steps

To a suspension of 2-((S)-2-o-tolyl-chroman-6-yloxy)-thiazole-5-carboxylic acid (2-hydroxy-ethyl)-amide (1 g, 2.44 mmol) and tetrazole (222 mg, 3.17 mmol, 1.3 eq) in dichloromethane (14 ml) and acetonitrile (14 ml) at 0° C., dibenzyl-N,N-diisopropylphosphoramidite (1.01 g, 2.92 mmol, 1.2 eq) was added and the mixture stirred at 0° C. for 70 min. To the resulting solution 3-chloro-perbenzoic acid (65%, 776 mg, 2.92 mmol, 1.2 eq) was added in one portion and vigorous stirring at 0° C. was continued for 10 min. The mixture was diluted with dichloromethane and the organic layer washed with a saturated aqueous solution of sodium hydrogencarbonate and subsequently with a saturated aqueous solution of ammonium chloride. The combined organic layers were dried over sodium sulfate and filtered, and the solvent removed under reduced pressure. The crude product was purified by column chromatography (silica gel, ethyl acetate). Phosphoric acid dibenzyl ester 2-{[2-((S)-2-o-tolyl-chroman-6-yloxy)-thiazole-5-carbonyl]-amino}-ethyl ester was obtained as a colorless oil (1.30 g, 80%).

Provenance & Evidence