Reference of 42098-25-9,Some common heterocyclic compound, 42098-25-9, name is 5-Chloro-1-methyl-4-nitro-1H-pyrazole, molecular formula is C4H4ClN3O2, 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.
Step 1: tert-Butyl 2-(2,6-difluorophenyl)-4-(1-methyl-5-(tert-butyloxycarbonylpyrrolidin-3-yl)-1H-pyrazol-4-ylcarbamoyl)thiazol-5-ylcarbamate 5-Chloro-1-methyl-4-nitro-1H-pyrazole (0.2 g, 1.24 mmol), tert-butyl 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,5-dihydro-1H-pyrrole-1-carboxylate (0.437 g, 1.48 mmol) and aqueous Na2CO3/KOAc solution (1:1, 1.1 M, 1.5 mL) were suspended in MeCN (5 mL). The mixture was degassed under a stream of nitrogen for 5 min. Pd(dppf)2Cl2 (0.1 g, 0.123 mmol) was added and the mixture was heated at 130 C. in a microwave for 90 min. A further portion of Pd(dppf)2Cl2 (50 mg, 0.06 mmol) was added and the mixture was heated at 130 C. for a further 90 min. The solvents were removed under reduced pressure and the crude residue partitioned between EtOAc and water. The organic layer was separated, dried over MgSO4 and concentrated under reduced pressure. The crude product was purified via silica gel column chromatography (40-60% EtOAc/isohexane) to give the intermediate nitro-pyrazole as a yellow oil (76 mg, 21%).
The synthetic route of 42098-25-9 has been constantly updated, and we look forward to future research findings.