Some common heterocyclic compound, 930-36-9, name is 1-Methylpyrazole, molecular formula is C4H6N2, 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. Quality Control of 1-Methylpyrazole
Step 1) Method A: Phosphorus oxychloride (6.92 g, 45.1 mmol, 1.5 eq.) was cooled to 0C and then added drop- wise to anhydrous DMF (3.50 mL, 45.2 mmol, 1.5 eq.) at 0C. The colorless DMF solution soon becomes orange. The mixture was stirred for 1 hour at room temperature and then heated to 80C. 1 -Methyl- IH-pyrazole (2.5 mL, 30.2 mmol) is then added drop-wise to the reaction, and the resulting mixture was stirred 3 hours at 95C. The reaction was then quenched by slow addition to ice (40 g) via Pasteur pipette. The pH of the resulting solution was 2, and it was raised to 5 by slowly adding 12N aqueous sodium hydroxide solution (11.2 mL total). The resulting aqueous solution was extracted with dichloromethane (3 x 40 mL). At this point, the pH of the aqueous layer had dropped to 3, therefore additional 12 N NaOH solution (1 mL) was added to bring the pH to 6. The aqueous layer was then extracted further with ether (4 x 40 mL). The combined extracts were then dried over sodium sulfate, filtered and concentrated (at about 40-50C). After drying for 30 minutes under vacuum, a brown oil was recovered (3.79 g) which NMR indicated consisted of a mixture of product, starting material and DMF (52 wt %, 22 wt %, and 26 wt %, respectively). The calculated yield of was 59% and the calculated yield for recovery of unreacted starting material, was 34%. This crude material may be used without further purification in the next step.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 930-36-9, its application will become more common.