[C:1]([CH2:7][C:8]#[N:9])(=[O:6])[C:2]([CH3:5])([CH3:4])[CH3:3].[OH-].[Na+].S(O)(O)(=O)=O.[NH2:17]O.Cl>O.S(=O)(=O)(O)O.C(Cl)(Cl)Cl>[NH2:9][C:8]1[CH:7]=[C:1]([C:2]([CH3:5])([CH3:4])[CH3:3])[O:6][N:17]=1
To a suspension of pivaloylacetonitrile (25.03 g) in water (400 ml) is added 96% sodium hydroxide (9.17 g). Hydroxylamine sulfate (18.06 g) is added to the resulting solution at 27° C. The mixture is stirred at room temperature for 30 minutes, adjusted to pH 8 with 10% sulfuric acid (0.97 g), stirred at 60° C. for 22 hours, cooled at 20° C., mixed with conc. hydrochloric acid (7.90 g), and heated at 50° C. for 2 hours. Conc. hydrochloric acid (14.18 g) is added to the mixture, which is heated at 100° C. for 1 hour. After cooling, the reaction mixture is adjusted to pH 11 with 30% sodium hydroxide (49.8 g) and shaken with chloroform. The organic layer is washed with water, dried over anhydrous sodium sulfate and concentrated to remove chloroform, whereby 3-amino-5-t-butylisoxazole (24.16 g) is obtained. Yield, 86.2%. Purity, 95.4%. m.p. 103.5-109° C.
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