Each compound has different characteristics, and only by selecting the characteristics of the compound suitable for a specific situation can the compound be applied on a large scale. 33146-99-5, name is Dimethyl 1-methyl-1H-pyrazole-3,5-dicarboxylate, This compound has unique chemical properties. The synthetic route is as follows., name: Dimethyl 1-methyl-1H-pyrazole-3,5-dicarboxylate
Sodium carbonate (2.14 kg, 20.2 mol) was added to a stirring solution of dimethyl 1 – methyl-1 H-pyrazole-3,5-dicarboxylate (7.95 kg, 40.1 mol) in MeOH (80 L) at 20±5 C. The slurry was stirred for 0.5 h and then filtered. The filter cake was washed with 2-methylTHF (16 L) and then the filtrates were returned to the reactor, followed by 2-methylTHF (24 L). The solution was cooled to 15±3 C and sodium borohydride (3.05 kg, 80.7 mol) was charged in ten portions at 15±3 C. The mixture was stirred for 2 h at 18±3 C after adding NaBH4. It was then quenched by gradually charging acetone (16.4 kg, 283 mol) at 18±3 C, then stirred for 1 h at 20±5 C. Aq. HCI (37 wt%, -8.6 Kg, 87 mol) was then slowly added, keeping the temperature below 30 C, to adjust the pH to 2-3, then the mixture was stirred for 1 h. Saturated aq. Na2CC>3 (~4L) was then slowly added to adjust the pH to 5-6, then the mixture was stirred for 3 h. The mixture was filtered and the filter cake was washed with DCM (16 L). The filtrates were concentrated to approximately 20 L by distillation under reduced pressure, not heating above 40C, then diluted with DCM (40 L) and concentrated again by distilling off solvent (approx. 40 L) under reduced pressure. DCM (80 L) and purified water (32 L) were charged and the resulting mixture was stirred for at least 10 min. The lower (organic) phase was collected and the upper (aqueous) phase was extracted four times with more DCM (40 L per portion). The combined organic phases were concentrated to approximately 20 L by vacuum distillation below 40 C. DCM (80 L) was added and the solution was concentrated again by distilling off solvent (approx. 40 L). The resulting methyl 5-(hydroxymethyl)-1-methyl-1 H-pyrazole-3-carboxylate solution was then diluted with DCM (80 L) and cooled to 10±5 C, whereupon thionyl chloride (4.80 kg, 40.4 mol) was gradually added while keeping the temperature below 15 C. The mixture was then stirred for 1 h at 20±5 C. The mixture was concentrated to not more than 20 L by vacuum distillation below 40 C, then DCM (64 L) and purified water (80 L) were added. After phase separation, the lower (organic) phase was washed twice with aq. Na2CC>3 (9 wt%, 80 L per portion) and then with purified water (80 L). The washed organic phase was concentrated to approximately 14 L by vacuum distillation below 40 C. Two cycles of slowly adding heptane (40 L) and then vacuum distilling to approximately 24 L at below 45 C were then completed. More heptane (40 L) was slowly added and the resulting slurry was stirred at 20±5 C for at least 0.5 h before filtering. The filter cake was washed with heptane (8.0 L) and then dried in a 45 C vacuum oven to give methyl 5-(chloromethyl)-1-methyl-1 H-pyrazole-3- carboxylate (Intermediate 10, 4.87 kg, 64%); m/z (ES+), [M+H]+ = 189. NMR (500 MHz, CDCIs, 27 C) delta 3.91 (s, 3H), 3.99 (s, 3H), 4.59 (s, 2H), 6.82 (s, 1 H).
According to the analysis of related databases, 33146-99-5, the application of this compound in the production field has become more and more popular.