Formaldehyde → (S)-3-[4-(3,4-Dichloro-benzyloxy)-phenyl]-1-methyl-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

To a solution of (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 (298 mg) in THF/DCE (30 mL, 2:1) was added paraformaldehyde (90 mg, 4 eq.) and sodium triacetoxy-borohydride (208 mg) and the mixture stirred 4 hours. DCM was added to the mixture and the organic washed with 10% Na2CO3 solution and brine. The organic was dried over sodium sulfate and the solvent removed under reduced pressure to afford the crude amine. The residue was purified by flash chromatography (hexanes/ethyl acetate from 80:20 to 60:40) to provide the product (277 mg).

Provenance & Evidence