tert-BUTYL CHLORIDE → Methyl 5-(tert-butyl)-3-methylthiophene-2-carboxylate

関与物質

反応条件

反応手順

A solution of methyl 3-methylthiophene-2-carboxylate 109a (33 g, 0.211 mol) in dry CH2Cl2 (30 mL) was added dropwise to a mixture of aluminum chloride (40 g, 0.297 mol) and dry CH2Cl2 (200 mL) at −78° C., under nitrogen. The reaction mixture was stirred for 10 min at −78° C., and a solution of tert-butyl chloride (23 mL, 0.211 mol) in dry CH2Cl2 (30 mL) was added dropwise at −78° C. The reaction mixture was stirred for 1 h at −78° C., gradually allowed to warm to room temperature and stirred for 16 h at room temperature. It was poured on ice and extracted with CH2Cl2 (2×200 mL). The organic layer was dried over anhydrous Na2SO4 and the solvent evaporated under vacuum. The obtained residue was purified by fractional distillation to yield methyl 5-tert-butyl-3-methylthiophene-2-carboxylate 109b (19 g, 43%) as a light yellow liquid.

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