Electric Literature of 3994-50-1,Some common heterocyclic compound, 3994-50-1, name is 1-Methyl-4-nitro-1H-pyrazole, molecular formula is C4H5N3O2, 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 N2 flushed pressure vial was added 5.6:1 of (S)-N-[( 15)-i -(6- chloropyridin2-yl)but-3-en- 1 -yl]-2-methylpropane-2-sulfinamide: (S)-N-[(iR)- 1 -(6-chloropyridin-2-yl)but-3 -en-i -yl] -2-methylpropane-2-sulfinamide (2. 18 g, 7.60 mmol), 1 -methyl-4-nitro- iH-pyrazole (0.966 g, 7.60 mmol), prepared as described in Intermediate 32A, di(adamant-i-yl)(butyl)phosphine (0.954 g, 2.66 mmol), PvOH (0.300 ml, 2.58 mmol), K2C03 (3.62 g, 26.2 mmol), Pd(OAc)2 (0.341 g, 1.52 mmol) and DMF (15.2 mL). The vial was purged with Ar. The vial was sealed and heated at 120 C overnight. Thereaction mixture was cooled to rt, partitioned between water and EtOAc, and the layers were separated. The aqueous layer was extracted with EtOAc (3x) and the organic layers were combined and concentrated. The crude product was purified using normal phase chromatography followed a second purification by reverse phase chromatography to give (S)-2-methyl-N-[( 1 R)- 1 -[6-( 1 -methyl-4-nitro- 1 H-pyrazol-5-yl)pyridin-2-yl]but-3-en- 1- yl]propane-2-sulfinamide (Diastereomer A) (0.275 g, 13%), MS(ESI) m/z: 274.4 (M+H) and (S)-2-methyl-N- [(1 S)- 1- [6-( 1 -methyl-4-nitro- 1 H-pyrazol-5 -yl)pyridin-2-yl]but-3-en-i-yl]propane-2-sulfinamide (Diastereomer B) (1.2 g, 57%); MS(ESI) m/z:274.4 (M+H).
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 1-Methyl-4-nitro-1H-pyrazole, its application will become more common.