Some common heterocyclic compound, 27006-76-4, name is 5-Chloro-1,3-dimethyl-1H-pyrazole-4-carboxaldehyde, molecular formula is C6H7ClN2O, 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. name: 5-Chloro-1,3-dimethyl-1H-pyrazole-4-carboxaldehyde
General procedure: All reactions were carried out in vials under nitrogen atmosphere. Step 1: A solution of compound 8 (100 mumol, 1.0 equiv) and compound 9 (150 mumol, 1.5 equiv) in DMF (0.1 M) was treated with K2CO3 (300 mumol, 3.0 equiv) and stirred at 110 C for 16 h (LCMS check). The reaction was filtered and the filtrate concentrated to afford 10. The crude aldehyde 10 (100 mumol, 1.0 equiv) was dissolved in acetone:water (2:1, 0.1 M) and treated with KMnO4 (600 mumol, 6 equiv) and stirred at 30 C for 16 h (LCMS check). The reaction was filtered and the filtrate concentrated to afford 11. The crude acid 11 (100 mumol, 1.0 equiv) was treated with HATU (120 mumol, 1.20 equiv) followed by the crude amine (100 mumol, 1.0 equiv) and NEt3 (300 mumol, 3.0 equiv). The reaction was stirred at 30 C for 16 h (LCMS check). The reactions were concentrated and purified directly by reversed phase preparative HPLC using a C18 column and eluting with acetonitrile-water (0.225% formic acid or pH = 10 NH4OH) gradient. All compounds were deemed greater than 95% purity by LCMS and HPLC.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 27006-76-4, its application will become more common.