Hydrochloric Acid → 3-Isoxazolamine, 5-(1,1-dimethylethyl)-

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Reaction Steps

A solution of 41.5 g of hydroxylamine hydrochloride in 136 ml of water was added drop-by-drop over a 10-minute period to a stirred, refluxing mixture of 56.1 g of pivaloylacetonitrile (British patent 2,014,992), 700 ml of water and 525 ml of ethanol. The mixture was held under those conditions for 7 hours, the pH of the mixture being periodically adjusted to 6.5 by the addition of either hydrogen chloride or aqueous sodium hydroxide solution, as required. Then the solvent ethanol was evaporated in a rotary evaporator, the residual liquid was dried (MgSO4), and placed in 200 ml of hexane and chilled. Filtration and fractional crystallization of the solid gave 3-amino-5-(tertiary-butyl)-1,2-oxazole (1A), a yellow solid, m.p.: 107°-109° C. A second fraction was 5-amino-3-(tertiary-butyl)-1,2-oxazole (1B), a solid, m.p.: 89°-90° C.

Provenance & Evidence