Electric Literature of 3469-69-0,Some common heterocyclic compound, 3469-69-0, name is 4-Iodopyrazole, molecular formula is C3H3IN2, 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.
1-(ethoxyethyl)-4-iodo-1H-pyrazole (20).; A 22 L 4-neck flask equipped with an mechanical stirrer, thermowell, N2 inlet and condenser was charged with 4-iodo-1H-pyrazole (14, 1.00 Kg, 5.16 mol) and toluene (10 L) and ethyl vinyl ether (18, 557 g, 740 mL, 7.73 mol, 1.5 equiv) was added. To the suspension 4 M HCl in dioxane (32 mL, 0.128 mol, 0.025 equiv) was added over 5 min with formation of a slightly thicker white suspension. The mixture was heated carefully to 35-40 C. at which point a mild exotherm to about 40 C. occurred with rapid dissolution of all solids to give a clear light yellow solution. The reaction mixture was heated at about 40 C. for an additional 0.5 hr until the GC analysis indicated the reaction was complete. The solution was allowed to cool to 25-30 C. and solid NaHCO3 (108 g, 1.29 mol, 0.25 equiv) was added. The suspension was stirred for 1 hr at room temperature to ensure the complete neutralization of HCl. The mixture was then filtered and the filtrate was concentrated under reduced pressure. The residual liquid was fractionally distilled to afford 1-(ethoxyethyl)-4-iodo-1H-pyrazole (20, 1.346 Kg, 1.373 Kg theoretical, 98%) as a pale yellow liquid (bp 89-93 at about 1 torr). For 20: 1H NMR (CDCl3, 250 MHz) delta ppm 7.61 (s, 1H), 7.47 (s, 1H), 5.46 (q, 1H, J=6.0 Hz), 3.48-3.23 (m, 2H), 1.60 (d, 3H, J=6.0 Hz), 1.11 (t, 3H, J=7.0 Hz); C7H11IN2O (MW, 266.08), LCMS (EI) m/e 267 (M++H).
The synthetic route of 3469-69-0 has been constantly updated, and we look forward to future research findings.