Hydrochloric Acid → 5-(1-Methoxy-2-methylpropan-2-yl)-1,2-oxazol-3-amine

Temperature

100 °C

To a stirred solution of 1.68 g (10.8 mmol) of 5-methoxy-4,4-dimethyl-3-oxo-pentanenitrile and 0.49 g (11.9 mmol) of sodium hydroxide in water (13 mL) is added a solution of 0.98 g (5.9 mmol) of hydroxylamine sulfate in water (4 mL). The reaction mixture is heated to 100° C. for 1.5 h. After this time, the reaction mixture is cooled to room temperature and 0.8 mL (9.7 mmol) of 37% aqueous HCl solution is added. The reaction is heated to 100° C. for 0.5 h. After cooling, the pH of the reaction mixture is adjusted to pH˜12 by addition of 1M aqueous NaOH solution and extracted with DCM (3×20 L). The organic layers are combined and washed with brine (20 mL), dried over Na2SO4 and filtered. The filtrate is concentrated under reduced pressure. The residual brown oil is purified by column chromatography (Biotage, eluent DCM, MeOH) to yield 0.94 g of 5-(2-methoxy-1,1-dimethyl-ethyl)-isoxazol-3-ylamine as a yellow oil. Yield 51%; m/z 171 [M+H]; 1H NMR (400 MHz, DMSO-d6) δ ppm 1.17 (6H, 2), 3.22 (3H, s), 3.26 (2H, s), 5.40 (2H, m) 5.53 (1H, s).

1. temperatureAfter this time, the reaction mixture is cooled to room temperature
2. temperatureThe reaction is heated to 100° C. for 0.5 h
3. temperatureAfter cooling
4. extractionextracted with DCM (3×20 L)
5. washwashed with brine (20 mL)
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationThe filtrate is concentrated under reduced pressure
9. customThe residual brown oil is purified by column chromatography (Biotage, eluent DCM, MeOH)

ORD record

ord-1873b8d4c671491bb8c1ae40bd62051e

Source dataset

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08372874B2