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

Participants

Reaction Steps

In a 100 ml. round bottom 3-neck flask there was placed 2 g. of pivalyl acetonitrile, 25 ml. of ethanol, and 10 ml. of water. While this mixture was refluxed, a solution of 0.89 g. of lithium hydroxide and 1.5 g. of hydroxylamine hydrochloride in 25 ml. of water was added. At the end of the addition, the pH of the reaction mixture was about 7.2. The pH was adjusted to about 6.8 using concentrated aqueous hydrochloric acid. After 30 minutes the pH was about 6.0 and was readjusted to about 6.5 using an aqueous solution of lithium hydroxide. After 1 hour the pH was about 6.2 and was adjusted to about 6.8 using an aqueous solution of lithium hydroxide. At 1.5 hours the pH was about 6.6. At 2 hours the pH was about 6.7. At 21/2 hours the pH was about 6.8. At 3 hours the pH was about 7.0 and was adjusted to about 6.5 using concentrated aqueous hydrochloric acid. After 20 hours the pH was about 7.0. The reaction mixture was cooled and the ethanol stripped on the rotovapor. The solid which precipitated was filtered off and dried. It weighed 1.4 g., had a melting point of about 105°-106° C., and was determined by vpc to contain 98.5% of 3-amino-5-(t-butyl)isoxazole and 1% of 5-amino-3-(t-butyl)isoxazole. Yield: 62.5% of desired isomer.

Provenance & Evidence