Dimethylformamide → HCID 58669398, compound

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Reaction Steps

A solution of 2-bromo-4-[(4-methoxyphenyl)sulfonyl]-5-ethyl-4,5-dihydrothieno[3,2-c]isoquinoline (2.3 g, 5.0 mmol) in dry tetrahydrofuran (45 mL) was cooled to −78° C. and treated with a solution of butyllithium in hexanes (1.35 M, 3.7 mL, 5.0 mmol) during ca. 2 min followed immediately by the fast addition of dry dimethylformamide (1.9 mL, 25 mmol). After 30 min further at −78° C., the reaction was quenched with 10% aqueous ammonium chloride (100 mL) and extracted with ethyl acetate (3×50 mL). The combined extracts were washed with brine (75 mL), dried (MgSO4), and concentrated in vacuo to give the crude product as a light orange solid (2.0 g) which was taken up in methylene chloride (ca. 8 ML) and pre-adsorbed on silica gel (8 g). Flash chromatography on silica gel (72 g) eluting 50-, then 75% methylene chloride-hexane, and then methylene chloride gave the title compound (1.7 g, 81%, m.p. 129-32° C.) as a pale yellow solid.

Provenance & Evidence