The synthetic route of 5334-39-4 has been constantly updated, and we look forward to future research findings.
Electric Literature of 5334-39-4, A common heterocyclic compound, 5334-39-4, name is 3-Methyl-4-nitro-1H-pyrazole, molecular formula is C4H5N3O2, 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.
To a solution of 3 -methyl -4-nitro-lH-pyrazole (5 g, 39.34 mmol) in DMF (50 rnL) was added NaH (1.89 g, 47.21 mmol, 60% purity) at 0 C under N2. The mixture was stirred at 20 C for 1 h, then added with ethyl 2-chloropropanoate (10.75 g, 78.68 mmol, 10.05 mL) and stirred for 15 h. The mixture was poured into ice water (250 mL). The aqueous phase was extracted with EtOAc (3 chi 100 mL). The combined organic phase was washed with brine (3 chi 100 mL), dried over anhydrous NaaS&t, filtered and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (PE:EtOAc = 2: 1), to give a mixture of ethyl 2-(5-methyi-4-nitro-pyrazoi-l-yl)propanoate and ethyl 2-(3- methyl-4-nitro-pyrazol-l-yl)propanoate as a yellow oil LCMS: RT 0.745 min, m/z = 228.2 [M+H]+ To a mixture of ethyl 2-(5-methyl-4-nitro-pyrazol-l -yl)propanoate and ethyl 2-(3-methyl-4-nitro- pyrazol-l-yl)propanoate (9.3 g, 40.93 mmol) in MeOH (90 mL) was added NaBH4 (3.87 g, 102.33 mmol) at 0 C under N2. The mixture was stirred at 0 C for 2 h. The mixture was concentrated under reduced pressure and purified by silica gel column chromatography (PE:EtOAc = 3: 1), to give a mixture of 2-(5- methyl-4-nitro-pyrazol- l-yl)propan-l -ol and 2-(3-methyl-4-nitro-pyrazol-l-y])propan-l-ol was obtained as a yellow solid. LCMS: RT 0.707 mm, m/z = 222.1 [M+H]+ To a solution of 2~(5 -methyl – -nitro- pyrazol-l-y])propan-l-ol, 2-(3-methyl-4-nitro-pyrazol-l-yl)propan-l-ol (2.08 g, 1 1.23 ramol) and Cul (428 mg, 2.25 mmol) in CCN (20 mL) was added a solution of 2,2-difluoro-2-fluorosulfonyl-acetic acid (3 g, 16.85 mmol, 1.74 mL) in CH3CN (10 mL) dropwise at 55C over a period of 30 min under N2. The reaction mixture was stirred at 55 C for 2.5 h. The mixture was concentrated under reduced pressure and purified by silica gel column chromatography (PE:EtOAc = 6: 1), to give a mixture of l-[2- (difluoromethoxy)-l -methyl-ethyl]-5-methyl-4-nitro-pyrazole and l-[2-(difluoromethoxy)-l-methyl- ethyi]-3-methyl-4-nitro-pyrazoie was obtained as a yellow oil. LCMS: RT 0.758 min, m/z = 236.52 i H | .To a mixture of l-[2- (ditluoromethoxy)-l-methyl-ethyl]”5-methyi-4-nitro-pyrazole and l-j2-(difiuoromethoxy)-l -methyl – ethyl]-3 -methyl -4 -nitro-pyrazole (760 mg, 3.23 mmol) in EtOH (20 mL) was added Fe (902.38 mg, 16.15 mmol) and NH4CI (864 mg, 16.15 mmol, 564.87 ,uL). The mixture was stirred at 80C for 2 h. The mixture was cooled to 20 C and concentrated under reduced pressure. The residue was poured into ice water (10 mL). The aqueous phase was extracted with EtOAc (3 x 10 mL). The combined organic phase was washed with brine (10 mL), dried over anhydrous NazSC^, filtered and concentrated under reduced pressure, to give a crude l-[2~(difiuoromethoxy)-l~methyl-ethyl]~5-methyi-pyrazol-4-amine and l-[2- (difluoromethoxy)-l-methyl-ethy]]-3-methyl-pyrazol-4-amine, which was used into the next step without further purification. LCMS: RT 1.026 min, nv’z = 186.1 | M ¡¤ 1 1 | To a mixture of 2-chloro-N-methyl-5-(trifluoromediyl)pyrimidin-4-ainine (372 rng, 1.75 mmol), l-[2- (difiuoromethoxy)- 1 -methyl-ethyl] -3 -methyl -pyrazol-4-amme and 1 – [2-(difluoromethoxy)- 1 -methyl – ethyi]-5-methyl-pyrazol-4-amine (300 mg, 1.46 mmol) in 1,4-dioxane (10 mL) was added TEA (295 mg, 2.92 mmol, 404.75 muTau) in one portion under N2. The mixture was stirred at 120 C for 2 h . The mixture was concentrated under reduced pressure. The residue was purified by prep-HPLC (FA). N2-[l-[2-(difluoromethoxy)-l-methyl-ethyl]-5-methyl-pyrazol-4-yl]-5-(difluoromethyl- fluoranyl)-N4-methyl^yrimidine-2,4-diamine (D-48): [H NMR (400 MHz, CDC M: delta 8, 10 (s, 1 H), 7.85 (br. s., 1 H), 6.62 (br, s, 1 H), 5.86 – 6.31 (m, 1 I I). 5.14 (br. s., 1 H), 4,44 – 4.55 (m, 1 H), 4.22 (t, J=9,48 Hz, 1 H), 4.08 (dd, J=10.36, 5.07 Hz, 1 H), 3.00 (d, ,7=4.85 Hz, 3 H), 2.18 – 2.30 (m, 3 H), 1.53 (d, ,7=7.06 Hz, 3 H): HPLC: RT 1.94 mm; MS: m/z = 381.1 j M ‘N2-[l-[2-(difluoromethoxy)-l-methyl-ethyl]-3-methyl-pyrazol-4-yl]-N4-methyl-5- (trifluoromethyl)pyrimidine-2, -diamine (D-21): NMR (400 MHz, CDC13): 5 8.12. (br. s., 1 H), 7.92 (br. s? 1 H), 6,97 (br. s, 1 H), 5.88 – 6.38 (m, 1 H), 5.21 (br. s? 1 H), 4,47 (d, .7=5,52 Hz, 1 H), 3.99 – 4,20 (m, 2 H), 3.06 (d, J=2.89 Hz, 3 1 1). 2.26 (s, 3 H), 1.56 (d, ,7=6.78 Hz, 3 H). HPLC: RT 1.93 mm; MS: m/z: 381.1 [M4-H]+.
The synthetic route of 5334-39-4 has been constantly updated, and we look forward to future research findings.