N-bromobutanimide → Methyl 2-(4-(4-cyanobenzyl)piperazin-1-yl)thiazole-5-carboxylate

Participants

Reaction Steps

A solution of (E)-methyl 3-methoxyacrylate (290 mg, 280 mL, 2.51 mmol) in 1:1 mixture of dioxane/water (4 mL) was treated with NBS (507 mg, 2.85 mmol) at 0° C. and stirred for 1 hour. The mixture was transferred to a flask containing the thioamide 337 (593 mg, 2.28 mmol) at room temperature and the resulting mixture was refluxed for 1.5 hours. It was cooled down, quenched by adding saturated NH4Cl solution (5 mL) and concentrated. Obtained material was partitioned between EtOAc and water. Organic phase was dried with Na2SO4, filtered and concentrated. The crude product was purified by flash chromatography using 60% EtOAc in hexanes as an eluent, to afford the title compound 338 (602 mg, 77% yield). MS: calc: 342.1; found: 343.1 (M+H)

Provenance & Evidence