反应详情

温度

-5 °C

To a stirred mixture of 2 M aqueous NaOH (75 mL, 152 mol) and 2-methyltetrahydrofuran (155 ml) was added N-[5-(2-chlorophenyl)-2H-pyrazol-3-yl]-acetamidine, acetate salt (I-1A-1a; 11.5 g, 39.0 mmol), portionwise, over 15 minutes at room temperature. The organic layer was separated, washed with brine (75 ml), and then concentrated to one half volume, at which time a precipitate begins to form. The stirred mixture was diluted with MTBE (70 mL), cooled to −5° C. in an ice/brine bath for 1 hour, and the resulting precipitate collected on a course sintered glass funnel. The solid was washed with ice cold MTBE (50 mL) and then dried, in vacuo, to afford intermediate I-1A-1b as a solid (5.74 g, 63%): +ESI MS (M+1) 235.3; 1H NMR (400 MHz, CD3OD) δ 7.56-7.53 (m, 1H), 7.48-7.44 (m, 1H), 7.36-7.28 (m, 2H), 6.27 (s, 1H), 2.04 (s, 3H).

1. customThe organic layer was separated
2. washwashed with brine (75 ml)
3. concentrationconcentrated to one half volume, at which time a precipitate
4. customto form
5. customthe resulting precipitate collected on a course sintered glass funnel
6. washThe solid was washed with ice cold MTBE (50 mL)
7. customdried, in vacuo