Electric Literature of 1904-31-0,Some common heterocyclic compound, 1904-31-0, name is 1-Methyl-1H-pyrazol-3-amine, molecular formula is C4H7N3, 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.
Example 113; 4-(3,5-Difluoro-phenoxy)-2,2-dimethyl-2,3-dihydro-benzofuran-6-carboxylic acid (1-methyl-1H-pyrazol-3-yl)-amide; To a mixture of 4-(3,5-difluoro-phenoxy)-2,2-dimethyl-2,3-dihydro-benzofuran-6-carboxylic acid (113b) (0.308 g, 0.00096 mol), EDCI (0.28 g, 0.0015 mol), HOBt (0.21 g, 0.0015 mol) and NMM (0.49 g, 0.0048 mol) in CH2Cl2 (15 mL) was added 1-methyl-1H-pyrazol-3-amine (0.11 g, 0.001 mol) in one portion. The mixture was stirred at room temperature overnight. The reaction mixture was washed with water, aq. citric acid and then sat. NaHCO3. The organic phase was dried over Na2SO4 and concentrated to give a brown oil. The crude oil was purified by prep. HPLC to give the title compound (95 mg, 51percent yield) as a white solid. 1H NMR (400 MHz, CDCl3): delta 8.82 (s, 1H), 7.20 (m, 2H), 7.03 (d, 2H), 6.73 (s, 1H), 6.42 (m, 3H), 3.72 (s, 3H), 2.84 (s, 2H), 1.42 (s, 6H); LCMS for C21H19F2N3O3 m/z 400.4 (M+H)+.
The synthetic route of 1904-31-0 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Pfizer Inc.; US2008/280875; (2008); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics