Potassium Hydroxide → 2-((Tert-butoxycarbonyl)amino)-3,3-dimethylpent-4-enoic acid

Temperature

70 °C

To a round bottom flask was added ethyl 2-(tert-butoxycarbonylamino)-3,3-dimethylpent-4-enoate (280 mg, 1.03 mmol), EtOH (20 mL) and aqueous 1 N NaOH (5.16 mL, 5.16 mmol). The reaction was stirred at 70° C. overnight. The reaction was cooled to rt and KOH (232 mg, 4.13 mmol) was added and the reaction was stirred at rt for 3 days. The solvent was removed and the residue was dissolved in water (15 mL). The aqueous solution was washed with DCM (5 mL). The pH of the aqueous layer was then adjusted to <4 using aqueous 1 N HCl. Then, the aqueous solution was extracted with DCM (5×10 mL). The combined organic layers were washed with saturated aqueous NaCl (20 mL). The organic layer was separated, dried over MgSO4, filtered and concentrated to give 2-(tert-butoxycarbonylamino)-3,3-dimethylpent-4-enoic acid (240 mg, 0.986 mmol, 96% yield) as beige solid. 1H NMR (500 MHz, CDCl3) δ ppm 5.87 (dd, J=17.32, 10.72 Hz, 1H), 5.23-5.03 (m, 2H), 4.98 (d, J=8.25 Hz, 1H), 4.17 (d, J=8.80 Hz, 1H), 1.45 (s, 9H), 1.16 (d, J=4.40 Hz, 6H).

1. temperatureThe reaction was cooled to rt
2. stirringthe reaction was stirred at rt for 3 days
3. customThe solvent was removed
4. dissolutionthe residue was dissolved in water (15 mL)
5. washThe aqueous solution was washed with DCM (5 mL)
6. extractionThen, the aqueous solution was extracted with DCM (5×10 mL)
7. washThe combined organic layers were washed with saturated aqueous NaCl (20 mL)
8. customThe organic layer was separated
9. dry with materialdried over MgSO4
10. filtrationfiltered
11. concentrationconcentrated

ORD record

ord-b9c2c5a0245f45dc9742b7ac4a850648

Source dataset

uspto-grants-2016_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09346852B2