1192-21-8, A common heterocyclic compound, 1192-21-8, name is 1-Methyl-1H-pyrazol-5-amine, molecular formula is C4H7N3, 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.
Heat a solution of 2,4-dichloropyridine (15.3 g, 103 mmol), L-methyi5 aTninopyrazole (ii g, 113 mmoi), cesium carbonate (6 g, 10 nimol) and tris(dibenzyiideneacetone)dipaiiadium(0) (4.7 g, 5 mmoi) in 1 ,4dioxane (750 niL) in asealed vessel at 75 ¡ãC overnight. Cool the reaction to room temperature and dilute with water (1.5 L). Extract the mixture with three portions DCM, Filter the aqueous layer to remove solids and extract the filtrate with two portions EtOAc. Combine all organic extracts, dry over magnesium sulfate, filter and concentrate the filtrate. Purify the residue by silica gel column chromatography by loading the product onto a 260 g pre-coiumn andeluting the pre-colunin onto a 750 g column with a gradient from 1-5percent MeOH in DCM to give the title compound 16.8 g (78percent). MS (m/z): 209 (M+i),
The synthetic route of 1-Methyl-1H-pyrazol-5-amine has been constantly updated, and we look forward to future research findings.