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

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.

1. customround bottom 3-neck flask there was placed
2. temperatureWhile this mixture was refluxed
3. additionAt the end of the addition
4. waitAfter 1 hour the pH was about 6.2
5. waitAt 1.5 hours the pH was about 6.6
6. waitAt 2 hours the pH was about 6.7
7. custom2 hours
8. waitAt 3 hours the pH was about 7.0
9. waitAfter 20 hours the pH was about 7.0
10. temperatureThe reaction mixture was cooled
11. customThe solid which precipitated
12. filtrationwas filtered off
13. customdried

ORD record

ord-d4dd725c59234f7e9aa63952ebc7b2fb

Source dataset

uspto-grants-1981_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04259501