Pentane → 5-Ethyl-4-[(4-methoxyphenyl)sulfonyl]-2-vinyl4,5-dihydrothieno[3,2-c]isoquinoline

Participants

Reaction Conditions

Reaction Steps

A suspension of methyltriphenylphosphonium bromide (2.30 g, 6.44 mmol) in dry tetrahydrofuran (16 mL) was treated dropwise with a pentane solution of t-butyllithium (1.0 M, 3.9 mL, 3.9 mmol) at 0° C. during several min. After the addition was complete, the suspension was warmed to 23° C. and after a further 10 min, a solution of 5-ethyl-4-[(4-methoxyphenyl)sulfonyl]-4,5-dihydrothieno[3,2-c]isoquinoline-2-carbaldehyde (1.33 g, 3.22 mmol) in dry tetrahydrofuran (16 mL+8 mL wash) was added. After a further 15 min, the reaction was quenched with water (160 mL) and extracted with ethyl acetate (160 mL). The extract was washed with brine (160 mL), dried (Na2SO4), and concentrated in vacuo to give the crude product as an orange solid (2.46 g). Flash chromatography on silica gel (24 g) eluting 25-, and then 50% methylene chloride-hexane gave the title compound (1.20 g, 90%, m.p. 131-33° C.) as a pale yellow solid.

Provenance & Evidence