Triethylamine → tert-butyl 4-[2,5-dioxo-1-(tetrahydro-2H-pyran-4-ylmethyl)-5-{5-[(tetrahydro-2H-pyran-2-yloxy)methyl]-1,3-thiazol-2-yl}pentyl]benzoate

Participants

Reaction Steps

To a solution of tert-butyl 4-[2-oxo-1-(tetrahydro-2H-pyran-4-ylmethyl)but-3-en-1-yl]benzoate (1.50 g) in ethanol (15 mL) were added 5-[(tetrahydro-2H-pyran-2-yloxy)methyl]-1,3-thiazole-2-carbaldehyde (1.20 g), 3-benzyl-5-(2-hydroxyethyl)-4-methyl-1,3-thiazol-3-ium chloride (130 mg) and triethylamine (260 μL), and the mixture was stirred with heating under reflux for 4 hr. After cooling to room temperature, the reaction mixture was diluted with ethyl acetate and washed with water. The ethyl acetate layer was washed with saturated brine, dried (MgSO4) and concentrated. The residue was subjected to silica gel column chromatography, and the title compound (2.37 g, yield 95%) was obtained as a colorless amorphous solid from a fraction eluted with ethyl acetate-hexane (1:1, volume ratio). MS: 488 (MH+).

Provenance & Evidence