1,2-Dichloroethane → 4-[4-(6-Chloro-pyridin-3-yl)-buta-1,3-diynyl]-benzoic acid methyl ester

Participants

Reaction Steps

DIEA (9.7 ml, 55.1 mmol) was added to a stirred solution of 4-iodo-benzoic acid (5.49 g, 22.2 mmol), HOAT (3.08 g, 22.6 mmol), EDC (4.33 g, 22.6 mmol) in DMF (85 ml). After 2 min., the H-DAP(Boc)-OMe (1) was added in one portion. After 12 hours, the reaction was found complete by LCMS. The reaction was diluted with EtOAc/hexane (1:1) (500 ml). The organic phase was washed with 1N HCl (2×80 ml), 1N NaOH (2×80 ml), water (2×80 ml), sat. brine (80 ml), dried with Na2SO4, filtered and concentrated under reduced pressure to give crude product. The residue was filtered through a filter plug of silica eluting with EtOAc/hexane (1:1). The fractions with product were evaporated to give 9.3 g of product (3-tert-Butoxycarbonylamino-2-(4-iodo-benzoylamino)-propionic acid methyl ester) in 93% yield. This product was converted to analogues in a similar manner as the aforementioned Examples.

Provenance & Evidence