Cesium carbonate → Ethyl 5-(4-methyl-1,4-diazepan-1-yl)thiophene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

Palladium(II)acetate (0.135 g, 0.60 mmol) was added to ethyl 5-bromothiophene-2-carboxylate (1.411 g, 6 mmol), 1-methyl-1,4-diazepane (0.822 g, 7.20 mmol), BINAP (0.374 g, 0.60 mmol) and cesium carbonate (2.74 g, 8.40 mmol) in dioxane (40 mL) warmed to 80° C. for 18 h under nitrogen. The crude reaction mixture was purified by ion exchange chromatography, using a SCX column. The desired product was eluted from the column using 7M NH3/MeOH. Fractions were evaporated to dryness to afford the crude product. The crude product was purified by silica column chromatography, eluting with a gradient of 0 to 5% 3M ammonia/MeOH in DCM. Pure fractions were evaporated to dryness to afford ethyl 5-(4-methyl-1,4-diazepan-1-yl)thiophene-2-carboxylate (0.204 g, 12.67%) as a yellow gum.

Provenance & Evidence