The major producers of chemicals have been the Europe, Japan and China. Due to the growing call for a cleaner, greener environment, people will have to find innovative ways to maintain their relevance. Here is a compound 193274-02-1, name is tert-Butyl 3a-benzyl-2-methyl-3-oxo-3a,4,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine-5(3H)-carboxylate. This compound has unique chemical properties. The synthetic route is as follows. HPLC of Formula: C19H25N3O3
Step D. 3a(R)-Benzyl-2-methyl-2,3,3a,4,6,7-hexahydro-pyrazolo[4,3-c]pyridin-3-one (L)-tartrate . To a 2 liter, round bottom flask, equipped with a mechanical stirrer, addition funnel, and a thermocouple was added, sequentially, 3a-(R,S)-benzyl-2-methyl-3-oxo-2,3,3a,4,6,7-hexahydro-pyrazolo[4,3-c]-pyridine-5-carboxylic acid tert-butyl ester (prepared according to Step C, 51.5g, 0.15 moles, 1.0 equivalents) and methylene chloride (515 ml, 10 volumes). The mixture was agitated to form a solution which was then cooled to an internal temperature of 0C-5C. To the cooled mixture was added trifluoroacetic acid (TFA, 130ml, 192g, 1.68 moles, 11.2 eq., 2.5 volumes). The TFA was added via the addition funnel over 15 minutes while maintaining an internal temperature of 0C-5C. The reaction mixture was warmed to about 20C over 3 hours and then the reaction mixture was cooled to 10C-15 C. To the cooled reaction mixture was added sodium carbonate (92g, 0.868 moles) in water (920 mL) over 20 minutes. The pH was 7.5. The reaction mixture was transferred to a 2 liter separatory funnel and allowed to settle. The organic portion was decanted and the aqueous portion was extracted with methylene chloride (130ml, 2.5 volumes). The combined organic portions were transferred back to the 2 liter reactor and to it was added L-tartaric acid (24.77g, 0.165 moles, 1.1 equivalents) dissolved in acetone (354 ml, about 7 volumes) and water (44mL, about 1 volume). The reaction mixture was agitated and heated at about 38C overnight. The resultant slurry was cooled to 0C-5C, granulated for 1 hour, then filtered. The solids were washed with 100ml of cold acetone and then dried in vacuoat 40C-50C for 16 hours to afford 51.86g (87.9% yield) of the title compound of Step D.
With the rapid development of chemical substances, we look forward to future research findings about 193274-02-1.
Reference:
Patent; Pfizer Products Inc.; EP1031575; (2000); A1;,
Pyridine – Wikipedia,
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