Electric Literature of 5932-27-4, These common heterocyclic compound, 5932-27-4, name is Ethyl 1H-pyrazole-3-carboxylate, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.
DMF (40 mL) was added to a flask containing ethyl 1H-pyrazole-3-carboxylate (1.5 g, 10.70 mmol), sodium hydride (0.5 14 g, 12.84 mmol, 60percent dispersion in mineral oil) at 0 °C. After 15 mm at 0 °C, the reaction mixture was allowed to warm up to RT and stirred at RT for 30 mm. The reaction mixture was cooled to 0 °C and a solution of 2-(3-bromopropyl)-2-methyl-1,3- dioxolane (2.69 g, 12.84 mmol), and potassium iodide (0.355 g, 2.141 mmol) in DMF (20 mL)was added. The reaction mixture was stirred at 0 °C for 15 mm, then allowed to warm up to RT and stirred at RT for 16 h. After cooling to 0 °C, the reaction mixture was quenched with aq NH4C1 (30 mL), and all DMF was removed under high vacuum. The residue was diluted withEtOAc (200 mL), washed with brine, dried over Na2SO4, filtered, and concentrated. Flash chromatography (EtOAc/hexanes) afforded Example 113A (0.88 1 g, 3.28 mmol, 31 percent yield) and Example 113B (1.724 g, 6.43 mmol, 60 percent yield). LCMS (ES): m/z 269.10 [M+Hjt Example 113A: 1H NMR (400 MHz, CDC13) oe 7.43 (d, J1.7 Hz, 1H), 6.79 (d, J2.0 Hz, 1H), 4.55 (t,J7.3 Hz, 2H), 4.30 (q,J7.1 Hz, 2H), 3.88 (br d,J=2.9 Hz, 4H), 1.97- 1.84 (m, 2H), 1.71 – 1.57(m, 2H), 1.34 (t,J=7.1 Hz, 3H), 1.26 (s, 3H). Example 113B: 1HNMR(400 MHz, CDC13) oe 7.38(d, J1.7 Hz, 1H), 6.74 (d, J1.7 Hz, 1H), 4.34 (q, J=7. 1 Hz, 2H), 4.17 (br t, J=7.2 Hz, 2H), 3.98-3.69 (m, 4H), 2.02- 1.90 (m, 2H), 1.67- 1.52 (m, 2H), 1.34 (t,J=7.1 Hz, 3H), 1.24 (s, 3H).
The synthetic route of 5932-27-4 has been constantly updated, and we look forward to future research findings.