Lithium Hydroxide → (1R,2S,4R)-3-[Isopropyl-(2-hydroxy-4-methyl-cyclohexanecarbonyl)-amino]-5-phenyl-thiophene-2-carboxylic acid

Temperature

50 °C

(1R,2S,4R)-3-[Isopropyl-(2-Acetoxy-4-methyl-cyclohexanecarbonyl)-amino]-5-phenyl-thiophene-2-carboxylic acid methyl ester (36 mg, 0.17 mmol) was dissolved in a mixture of dioxane:H2O (4:1) (700 μl) and then 470 μl of LiOH 1N was added to it. After 3 h at 50° C. the reaction mixture was cooled to room temperature and the solvents were removed. The residue was then partitioned between 10 ml of H2O acidified to pH 4 and 10 ml of EtOAc. The organic layer was separated and the aqueous phase was washed with ethyl acetate (2×10 ml). The combined ethyl acetate layers were dried (Na2SO4), concentrated and the residue was purified by preparative chromatography to obtain 9 mg (29%) of (1R,2S,4R)-3-[Isopropyl-(2-hydroxy-4-methyl-cyclohexanecarbonyl)-amino]-5-phenyl-thiophene-2-carboxylic acid. NMR 1H (CDCl2, 400 MHz): 3:2 mixture of rotamers 7.76-7.73 ppm (m, 2H, Haro); 7.50-7.38 ppm (m, 3H, Haro); 7.36 ppm (s, 1H, Haro); 4.93-4.87 ppm (m, 1H); 4.25 ppm (s, 0.70H, major rotamer); 3.97 ppm (s, 0.3H, minor rotamer); 2.35-2.28 ppm (m, 1H); 1.99-1.53 ppm (m, 5H); 1.28 ppm (d, 0.6H, minor rotamer); 1.25 ppm (d, 1.4H, major rotamer); 1.06-1.03 ppm (m, 3H), 0.96-0.72 ppm (m, 1H); 0.79 ppm (d, 3H); 0.67-0.56 ppm (m, 1H).

1. customthe solvents were removed
2. customThe residue was then partitioned between 10 ml of H2O
3. customThe organic layer was separated
4. washthe aqueous phase was washed with ethyl acetate (2×10 ml)
5. dry with materialThe combined ethyl acetate layers were dried (Na2SO4)
6. concentrationconcentrated
7. customthe residue was purified by preparative chromatography

ORD record

ord-d181a01479454076b6764d4040988e25

Source dataset

uspto-grants-2012_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08329924B2