Diisopropylethylamine → ethyl-2-[1-[[5-methyl-3-(trifluoromethyl)-1H-pyrazol-1-yl]acetyl]-4-piperidinyl]-4-thiazolecarboxylate

To a solution of (5-methyl-3-trifluoromethyl-pyrazol-1-yl)-acetic acid (9.1 g, 36.1 mmol) in DMF (100 mL) is added diisopropylethylamine (45 mL, 216 mmol), followed by O-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate (15.5 g, 39.7 mmol). After stirring 15 min at RT, 2-piperidin-4-yl-thiazole-4-carboxylic acid ethyl ester hydrochloride (10 g, 36.1 mmol) is added to the reaction mixture. After stirring overnight at RT, solvent is evaporated and the resulting yellow oil is dissolved in ethylacetate (300 mL), washed with saturated aqueous sodium bicarbonate solution (300 mL), 1M HCl solution (300 mL), and brine (100 mL). The organic layer is dried over sodium sulfate, filtered, and evaporated under reduced pressure. The crude mixture is purified by column chromatography on silica gel (dichloromethane/methanol 10:1) to give 2-{1-[2-(5-methyl-3-trifluoromethyl-pyrazol-1-yl)-acetyl]-piperidin-4-yl}-thiazole-4-carboxylic acid ethyl ester (13.6 g, 88%). 1H-NMR (400 MHz, CDCl3): δ=1.40 (t, 3H), 1.70-1.85 (m, 2H), 2.16-2.30 (m, 2H), 2.32 (s, 3H), 2.79-2.89 (m, 1H), 3.22-3.43 (m, 1H), 4.03-4.12 (m, 1H), 4.42 (q, 3H), 4.54-4.69 (m, 1H), 4.93-5.08 (2 d, 2H (diastereotopic)), 6.35 (s, 1H), 8.10 (br, 1H). MS: m/z=209 (M+1).

1. stirringAfter stirring overnight at RT
2. customsolvent is evaporated
3. dissolutionthe resulting yellow oil is dissolved in ethylacetate (300 mL)
4. washwashed with saturated aqueous sodium bicarbonate solution (300 mL), 1M HCl solution (300 mL), and brine (100 mL)
5. dry with materialThe organic layer is dried over sodium sulfate
6. filtrationfiltered
7. customevaporated under reduced pressure
8. customThe crude mixture is purified by column chromatography on silica gel (dichloromethane/methanol 10:1)

ORD record

ord-75cd0adfd50f4f5683435fd8b89de29c

Source dataset

uspto-grants-2014_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08748431B2