Electric Literature of 345637-71-0,Some common heterocyclic compound, 345637-71-0, name is 2-(5-Methyl-3-(trifluoromethyl)-1H-pyrazol-1-yl)acetic acid, molecular formula is C7H7F3N2O2, 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.
Preparation of Starting Materials of the Formula (IVb): 1-[4-(4-Acetyl-1,3-thiazol-2-yl)piperidin-1-yl]-2-[5-methyl-3-(trifluoromethyl)-1H-pyrazol-1-yl]ethanone (IV-1); Oxalyl chloride (1.74 g) and a drop of N,N-dimethylformamide are added to a solution of [5-methyl-3-(trifluoromethyl)-1H-pyrazol-1-yl]acetic acid (1.00 g) in dichloromethane (10 ml). The reaction mixture is then stirred for 24 hours. Excess oxalyl chloride is then removed under reduced pressure, and the residue is once more dissolved in dichloromethane (10 ml). With ice-bath cooling, the solution is then added to a suspension of 1-[2-(piperidin-4-yl)-1,3-thiazol-4-yl]ethanone hydrochloride (1.13 g) in dichloromethane (10 ml) and N,N-diisopropylethylamine (1.77 g). The reaction mixture is then allowed to warm to room temperature and stirred for a further 2 hours. Saturated aqueous ammonium chloride solution (5 ml) is then added to the reaction mixture. The aqueous phase is separated off and extracted with dichloromethane. All the organic phases are combined and dried using anhydrous sodium sulphate. The solid is then filtered off, and the solvent is removed under reduced pressure. Purification by column chromatography (silica gel, ethyl acetate:hexane 0%-100% elution gradient) gives 1-[4-(4-acetyl-1,3-thiazol-2-yl)piperidin-1-yl]-2-[5-methyl-3-(trifluoromethyl)-1H-pyrazol-1-yl]ethanone (1.00 g, 52%) (log P(pH2.7)=2.25).1H NMR (DMSO-d6, 400 MHz): deltappm: 1.65 (bs, 1H), 1.80 (bs, 1H), 2.18-2.11 (m, 2H), 2.23 (s, 3H), 2.55 (s, 3H), 2.90 (bs, 1H), 3.28 (bs, 1H), 3.39 (m, 1H), 4.00 (bs, 1H), 4.33 (bs, 1H), 5.22 (bs, 2H), 6.45 (s, 1H), 8.36 (s, 1H)MS (ESI): 401 ([M+H]+)
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 2-(5-Methyl-3-(trifluoromethyl)-1H-pyrazol-1-yl)acetic acid, its application will become more common.