Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.
Procedure: Orthoethoxybenzamide (33.0 g, 0.20 mol) was added into a mixture of chlorosulfonic acid (60 mL) and thionyl chloride (20 mL) cooled by an ice bath in batches, and the temperature of the reaction system was kept below 20° C. After the completion of reaction identified by TLC, the reactant liquid was poured into chopped ice to separate a white solid. The product was extracted out with dichloromethane (200 mL), and N-ethylpiperazine (45.6 g, 0.40 mol) was added therein under an ice bath. The reaction mixture was reacted for 30 minutes under an ice bath, and then stirred for 1 hour at room temperature. Water (10 mL) was added therein to separate the liquid, and the organic phase was washed with saturated aqueous ammonium chloride solution (100 mL), dried over anhydrous sodium sulfate, and concentrated to 50 mL. Petroleum ether (100 mL) was dropped therein to separate a white acicular crystal, 58.6 g, and the final product was obtained by vacuum filtration with a yield of 86%. 1H NMR (CDCl3, 300 MHz) δ: 1.01 (3H, t), 1.56 (3H, t), 2.38 (2H, q), 2.50 (4H, t), 3.03 (4H, t), 4.28 (2H, q), 6.14 (1H, s), 7.06 (1H, d), 7.67 (1H, s), 7.82 (1H, dd), 8.58 (1H, d).
cooled by an ice bath in batches
was kept below 20° C
After the completion of reaction
the reactant liquid was poured into chopped ice
to separate a white solid
was added
The reaction mixture was reacted for 30 minutes under an ice bath
to separate the liquid
the organic phase was washed with saturated aqueous ammonium chloride solution (100 mL)
dried over anhydrous sodium sulfate
concentrated to 50 mL
Petroleum ether (100 mL) was dropped
to separate a white acicular crystal, 58.6 g
Source ID: ord-3445d395222949d19c832725e88c5481