Dichloromethane → (S)-3-[4-(3,4-Dichloro-benzyloxy)-phenyl]-1,2,3,5,7,8-hexahydro-4-oxa-1,6-diaza-anthracene-6,7-dicarboxylic acid 6-tert-butyl ester 7-methyl ester

Participants

Reaction Steps

[4-(3,4-Dichloro-benzyloxy)-phenyl]-oxo-acetaldehyde (616 mg) was dissolved in DCE (25 mL), and (S)-6-amino-7-hydroxy-3,4-dihydro-1H-isoquinoline-2,3-dicarboxylic acid 2-tert-butyl ester 3-methyl ester (644 mg) and sodium triacetoxyborohydride (520 mg) were added. The mixture was stirred overnight at room temperature. DCM (50 mL) was added to the reaction mixture and poured into water (25 mL). The organic layer was washed with 10% Na2CO3 solution and brine, and dried over sodium sulfate. The solvent was removed under reduced pressure and the residue was purified by flash chromatography (hexanes/ethyl acetate from 90:10 to 70:30) to give (S)-3-[4-(3,4-Dichloro-benzyloxy)-phenyl]-1,2,3,5,7,8-hexahydro-4-oxa-1,6-diaza-anthracene-6,7-dicarboxylic acid 6-tert-butyl ester 7-methyl ester (855 mg).

Provenance & Evidence