A common heterocyclic compound, 4522-35-4, name is 3-Iodo-1H-pyrazole, molecular formula is C3H3IN2, 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. 4522-35-4.
l-(But-3-en-l-yl)-3-iodo-lH-pyrazole. To a solution of 5-iodo-lH-pyrazole (1.34 g, 6.91 mmol, 1 equiv) in DMF (23 mL) was added 60% NaH (0.33 g, 8.29 mmol, 1.2 equiv). After 10 min, 4-bromobut-l-ene (0.84 mL, 8.29 mmol, 1.2 equiv) was added. After stirring 3 d, the reaction was added to water and extracted with EtOAc (x3). The combined EtOAc extracts were dried (Na2S04) and concentrated in vacuo. The crude product was purified by flash column chromatography (0-100%) EtOAc in hexane) to provide a 3: 1 mixture of product isomers (1.12 g, 65%>) as a colorless oil. Major isomer: 1H NMR (400 MHz, CDC13) delta 7.21 (d, J= 2.3 Hz, 1H), 6.39 (d, J= 2.3 Hz, 1H), 5.80 – 5.68 (m, 1H), 5.13 – 5.05 (m, 2H), 4.20 (t, J= 7.2 Hz, 2H), 2.61 (qt, J= 7.0, 1.3 Hz, 2H). Minor isomer: 1H NMR (400 MHz, CDC13) 7.53 (d, J= 1.8 Hz, 1H), 6.42 (d, J= 1.8 Hz, 1H), 5.81 (ddt, J= 17.1, 10.2, 6.9 Hz, 1H), 5.14 – 5.05 (m, 2H), 4.27 (t, J= 7.3 Hz, 2H), 2.65 – 2.58 (m, 2H).
The synthetic route of 3-Iodo-1H-pyrazole has been constantly updated, and we look forward to future research findings.