Application of 360056-45-7,Some common heterocyclic compound, 360056-45-7, name is Methyl 4-amino-1H-pyrazole-3-carboxylate, molecular formula is C5H7N3O2, 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.
A solution of 4-amino-1 H-pyrazole-3-carboxylic acid methyl ester (0.634 Kg, 4.49 mol, 1 wt) in 1 ,4-dioxane (8.90 L, 9 vol) under nitrogen was treated with triethylamine (0.761 L, 5.46 mol, 1.2 vol) followed by 2,6-dichlorobenzoyl chloride (0.710 L, 4.96 mol, 0.72 vol) such that the internal temperature was maintained in the range 20 to 25 0C. Residual 2,6- dichlorobenzoyl chloride was washed in with a line rinse of 1 ,4-dioxane (0.990 L, 1 vol) and the reaction mixture stirred at 18 to 25 C until complete (16 hours) by TLC analysis (eluent: ethyl acetate: heptanes 3:1 ; Rf amin80.25, Rf product 0.65). The reaction mixture was filtered, the filter-cake washed with 1 ,4-dioxane (2x 0.990 L, 2x 1 vol) and the combined filtrates (red) progressed to Stage 4 without further isolation.Triethylamine (1.42L, 10.20 MoI, 1.2 vol) was added to solution of 4-amino-1H-pyrazole-3- carboxylic acid methyl ester (1.184Kg, 8.39 MoI, 1.0 wt) in 1,4-dioxane (10.66L, 9.0 vol) at 15 to 25C under nitrogen. 2,6-Dichlorobenzoyl chloride (1.33L, 9.28 MoI, 1.12 vol) was charged at 15 to 250C followed by a line rinse of 1 ,4-dioxane (1.18L, 1.0 vol) and the reaction mixture stirred at 15 to 25C for 14 to 24 hours. Reaction completion was determined by 1H NMR analysis2. The reaction mixture was filtered, the filter-cake washed with 1 ,4-dioxane (2x 1.18L, 2x 1.0 vol) and the combined filtrates progressed to Stage 4 without further isolation.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Methyl 4-amino-1H-pyrazole-3-carboxylate, its application will become more common.
Reference:
Patent; ASTEX THERAPEUTICS LIMITED; WO2008/1101; (2008); A2;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics