2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → HCID 67195229, compound

Participants

Reaction Steps

methyl-5-bromo-isoquinoline-3-carboxylate was prepared using the following procedure describe in US054777252 for methyl-6,7-dimethoxy-isoquinoline-3-carboxylate: 5-bromo-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid methyl ester (880 mg, 3.26 mmol) was treated with 2,3-Dichloro-5,6-dicyanobenzoquinone (1.62 mg, 7.19 mmol) in dry tetrahydrofuran (19 ml) at reflux temperature for 18 hours. The cooled dark mixture was filtered and the solid washed with dichloromethane. The filtrate was treated with a 1M aqueous sodium hydroxide solution and the aqueous layer was extracted twice with dichloromethane. The organic layer was washed with water, brine, dried over sodium sulfate and concentrated to dryness. The residue was purified by flash chromatography over silica gel (gradient cyclohexane/ethyl acetate: 0-100%) to yield methyl 5-bromo-isoquinoline-3-carboxylate (793 mg, 91%) as beige solid.

Provenance & Evidence