In the chemical reaction process, reaction time, type of solvent, can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product. An updated downstream synthesis route of 5334-40-7 as follows. 5334-40-7
A 2OL reaction vessel equipped with a digital thermometer and stirrer was charged with A- nitro-1H-pyrazole-3-carboxylic acid (1.117Kg, 7.11mol, 1wt) and methanol (8.950L, deltavol). The reaction mixture was stirred under nitrogen, cooled to 0 to 50C, thionyl chloride (0.581 L, delta.Omol, 0.52vol) added over 180 minutes and the resultant mixture allowed to warm to and stir at 18 to 22C overnight after which time 1H NMR analysis (d6-DMSO) indicated reaction completion. The reaction mixture was concentrated under reduced pressure at 40 to 450C, the residue treated with toluene and re-concentrated (3x 2.250L, 3x 2vol) under reduced pressure at 40 to 450C to give 4-nitro-1 /-/-pyrazole-3-carboxylic acid methyl ester as an off-white solid (1.210Kg, 99.5%th).4-Nitro-1H-pyrazole-3-carboxylic acid (1.00kg, 6.37mol, 1.0wt) and methanol (8.00L, delta.Ovol) were charged to a flange flask equipped with a mechanical stirrer, condenser and thermometer. The suspension was cooled to 0 to 5C under nitrogen and thionyl chloride (0.52L, 7.12mol, 0.52vol) was added at this temperature. The mixture was warmed to 15 to 25C over 16 to 24 hours. Reaction completion was determined by 1H NMR analysis (d6- DMSO). The mixture was concentrated under vacuum at 35 to 45C. Toluene (2.00L, 2.0vol) was charged to the residue and removed under vacuum at 35 to 450C. The azeotrope was repeated twice using toluene (2.00L, 2.0vol) to give 4-nitro-1 H-pyrazole-3- carboxylic acid methyl ester (1.071 Kg, 98.3%) as an off white solid.Thionyl chloride (2.90 ml, 39.8 mmol) was slowly added to a mixture of 4-nitro-3- pyrazolecarboxylic acid (5.68 g, 36.2 mmol) in MeOH (100 ml) at ambient temperature and the mixture stirred for 48 hours. The mixture was reduced in vacuo and dried through azeotrope with toluene to afford 4-nitro-1 H-pyrazole-3-carboxylic acid methyl ester as a white solid.1H NMR (400 MHz, DMSO-d6) delta 14.4 (s, 1 H), 8.9 (s, 1 H), 3.9 (s, 3H)4-Nitro-1H-pyrazole-3-carboxylic acid (1.350Kg, 8.59 MoI, 1.0 wt) and methanol (10.80L, 8.0 vol) were charged to a flange flask equipped with a mechanical stirrer, condenser and thermometer. The suspension was cooled to O to 50C under nitrogen and thionyl chloride (0.702L, 9.62 MoI, 0.52 vol) added at this temperature. The mixture was warmed to 15 to 25C over 16 to 24 hours. Reaction completion was determined by 1H NMR analysis (d6- DMSO). The mixture was concentrated under vacuum at 35 to 45C and toluene (2.70L, 2.0 vol) charged to the residue and removed under vacuum at 35 to 45C. The toluene azeotrope was repeated twice using toluene (2.70L, 2.0 vol) to give 4-nitro-1 H-pyrazole-3- carboxylic acid methyl ester [1.467Kg, 99.8%th, 108.7% w/w, 1H NMR (d6-DMSO) concordant with structure, no entrained solvent] as an off-white solid.
According to the analysis of related databases, 5334-40-7, the application of this compound in the production field has become more and more popular.