反应详情

The 2-ethoxy-5-(4-ethylpiperazin-1-yl-sulfonyl)benzamidine hydrochloride prepared in the above preparation example 1 was dissolved into ethanol (200 ml), and 85% hydrazine hydrate (5.9 g, 0.1 mol) was slowly dropped into the solution under ice bath. The mixture was stirred for 30 minutes and then at room temperature for 1 hour. Then, the solution was concentrated to dryness, and added with ethyl acetate to perform a recrystallization. The separated crystal was dried under vacuum to obtain 28 g of product with a yield of 74%. 1H NMR (CDCl3, 300 MHz) δ: 1.02 (3H, t), 1.49 (3H, t), 2.39 (2H, q), 2.51 (4H, t), 3.05 (4H, t), 4.18 (2H, q), 7.00 (1H, d), 7.69 (1H, dd), 8.13 (1H, d). ESI-MS m/z 356.3 (M++1, 100).

1. additionwas slowly dropped into the solution under ice bath
2. waitat room temperature for 1 hour
3. concentrationThen, the solution was concentrated to dryness
4. additionadded with ethyl acetate
5. customa recrystallization
6. customThe separated crystal was dried under vacuum