Triethylamine → Methyl 4,5,6,7-tetrahydro-1-benzothiophene-2-carboxylate

Participants

Reaction Steps

To a solution of 2-chlorocyclohex-1-enecarbaldehyde (50 g, 346 mmol) and methyl-2-mercaptoacetate (40 g, 380 mmol) in Pyridine (100 mL) was added triethylamine (105 g, 1037 mmol) at room temperature. The mixture was stirred for 2 h, and partitioned between ethyl acetate (200 mL) and 1N aqueous HCl (50 mL). The separated organic layer was washed with brine, dried over Na2SO4 and evaporated to dryness, which was dissolved in Methanol (100 mL). To the above solution was added sodium methoxide (1.9 g, 34.6 mmol), then, the mixture was heated at reflux for 3 hrs, which was poured into ice water and partitioned between ethyl acetate (200 mL) and 1N aqueous NaHCO3 (50 mL). The separated organic layer was washed with brine, dried over Na2SO4 and evaporated to dryness, which was purified by silica gel chromatography eluted with PE:ethyl acetate 10:1 to give title product (25 g, 36% yield) as yellow solid. LCMS (m/z) ES+=197 (M+1)

Provenance & Evidence