Sodium Hydroxide → 3-Benzyl-2-propylthieno[2,3-d]pyrimidin-4(3H)-one

Participants

Reaction Conditions

Reaction Steps

A mixture of N-benzyl-2-(butyrylamino)thiophene-3-carboxamide (2-3, 230 mg, 0.76 mmol, 1 equiv) and sodium hydroxide (3 mg, 0.08 mmol, 0.1 equiv) in ethylene glycol (5 mL) was heated at 130° C. for 5 h. The reaction mixture was allowed to cool, then partitioned between a half-saturated aqueous sodium chloride solution and ethyl acetate (2×75 mL). The combined organic layers were dried over sodium sulfate and concentrated. The residue was purified by flash column (hexanes initially, grading to 100% ethyl acetate) to provide 3-benzyl-2-propylthieno[2,3-d]pyrimidin-4(3H)-one (2-4) as a colorless oil which solidified upon standing. 1H NMR (300 MHz, CDCl3) δ 7.48 (d, 1H, J=5.8 Hz), 7.31 (m, 3H), 7.19 (d, 1H, J=5.8 Hz), 7.17 (d, 2H, J=7.9 Hz), 5.42 (s, 2H), 2.72 (t, 2H, J=7.6 Hz), 1.78 (sextet, 2H, J=7.6 Hz), 0.97 (t, 3H, J=7.3 Hz). 3-benzyl-5,6-dibromo-2-(1-bromopropyl)thieno[2,3-d]pyrimidin-4(3H)-one (2-5) and 3-benzyl-6-bromo-2-(1-bromoyropyl)thieno[2,3-d]pyrimidin-4(3H)-one (2-6)

Provenance & Evidence