Category: 881668-70-8

Reference of 881668-70-8,Some common heterocyclic compound, 881668-70-8, name is 5-Chloro-1H-pyrazole-3-carboxylic acid, molecular formula is C4H3ClN2O2, 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.

Method E A mixture of TBTU (642 mg, 2.0 mmol), pyrazole-3-carboxylic acid or 5-chloro pyrazole-3-carboxylic acid (intermediate II) (1.0 mmol), the relevant arylamine (1.0 mmol), DIPEA (348 muL, 2.0 mmol) and DMAP (12 mg, 0.1 mmol) in dry DMF (5 mL) was stirred at 80 0C for 3 days. After cooling to rt the mixture was concentrated and hydrochloric acid (IM, 10 mL) was added. The mixture was extracted with EtOAc (4 x 10 mL) , the combined organic phases washed with NaCl (sat., aq.; 20 mL), dried (Na2SO4), concentrated and purified by chromatography (EtO Ac/heptane) to give the desired compound.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 5-Chloro-1H-pyrazole-3-carboxylic acid, its application will become more common.

Reference:
Patent; BIOLIPOX AB; WO2007/51981; (2007); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Synthetic Route of 881668-70-8, 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 881668-70-8 as follows.

Add in 100mL round bottom flask5-chloro-1H-pyrazole-3-carboxylic acid (0.122 g, 0.8355 mmol),1.5 mL of anhydrous DMF as a solvent, Add EDCI (0.16 g, 1.0444 mmol), DIPEA (0.24 mL, 1.3926 mmol) and HOBT (32 mg, 0.2089 mmol), Stir for 20 minutes. Add another starting material (S)-3-amino-N-(4-cyano-3-trifluoromethyl-phenyl)-2-hydroxy-2-methylpropanamide (0.20 g, 0.6963 mmol) a solution of 4.0 mL of anhydrous DMF, Then the reaction solution is under argon protection. Stir at room temperature for 3 days. After confirming the completion of the reaction by thin layer chromatography, ethyl acetate and water were added, the two phases were separated, and the organic phase was drained to obtain Oily substance. Separation by silica gel column chromatography (mobile phase: methylene chloride:methanol = 9:1), purified to give pale yellow powder 0.15 g, the yield was about 51.0%.

According to the analysis of related databases, 881668-70-8, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Yang Guohong; He Junze; Duan Meijuan; (34 pag.)CN108558760; (2018); A;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Related Products of 881668-70-8, 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 881668-70-8 as follows.

4,5-Dichloropyrazole-3-carboxyh’c acid (TV”)Chlorine gas was bubbled slowly through a stirred solution of 5-chloropyrazole-3- carboxylic acid (Intermediate II, 3.00 g, 20.5 mmol) in water (2.0 L) at rt over 3 h. The solution was stirred for 18 h in an open flask and then concentrated in vacuo. The slurry was extracted with ethyl acetate (3×100 mL), the combined extracts were washed with NaCl (sat., aq.; 100 mL) and dried (Na2SO4). The solvent was removed in vacuo to give the product as a white powder. Yield 3.20 g (86 %). MS (MT-H) Wk= 179. 1H NMR (DMSO^6, 400 MHz) delta 14.44 (s, IH), 14.09 (s, IH). 13CNMR (CD3OD, 100 MHz) delta 160.0; 139.6; 133.1; 112.4.

According to the analysis of related databases, 881668-70-8, the application of this compound in the production field has become more and more popular.

Reference:
Patent; BIOLIPOX AB; WO2007/51981; (2007); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics