Sodium Hydroxide → (E)-4-cyclopentyl-2-[4-(5-methyl-tetrazol-1-yl)-3-trifluoromethyl-phenyl]-but-2-enoic acid

Temperature

47.5 °C

A solution of (E)-4-cyclopentyl-2-[4-(5-methyl-tetrazol-1-yl)-3-trifluoromethyl-phenyl]-but-2-enoic acid methyl ester (359 mg, 0.9 mmol) in ethanol (5 mL) was treated E with a 1N aqueous sodium hydroxide solution (3 mL). The solution was heated at 45-50° C. for 15 h, at which time, thin layer chromatography analysis of the reaction mixture indicated the absence of starting material. The reaction mixture was concentrated in vacuo to remove ethanol. The residue was diluted with water (20 mL) and extracted with diethyl ether (1×30 mL) to remove any neutral impurities. The aqueous layer was then acidified with a 1N aqueous hydrochloric acid solution, and the resulting acid was extracted into ethyl acetate (2×30 mL). The combined organic layers were washed with a saturated aqueous sodium chloride solution (1×50 mL), dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo to afford (E)-4-cyclopentyl-2-[4-(5-methyl-tetrazol-1-yl)-3-trifluoromethyl-phenyl]-but-2-enoic acid (340 mg, 98%) as a yellow solid: EI-HRMS m/e calcd for C18H19F3N4O2 (M+) 380.1460, found 380.1460.

1. concentrationThe reaction mixture was concentrated in vacuo
2. customto remove ethanol
3. additionThe residue was diluted with water (20 mL)
4. extractionextracted with diethyl ether (1×30 mL)
5. customto remove any neutral impurities
6. extractionthe resulting acid was extracted into ethyl acetate (2×30 mL)
7. washThe combined organic layers were washed with a saturated aqueous sodium chloride solution (1×50 mL)
8. dry with materialdried over anhydrous magnesium sulfate
9. filtrationfiltered
10. concentrationconcentrated in vacuo

ORD record

ord-6e678f22a2b442a9a4c803cd27efbcc9

Source dataset

uspto-grants-2002_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06388088B1