Hydrochloric Acid → 4-Methyl-7-(phenylmethyl)-4,7-diazaspiro[2.5]octane

Temperature

0 °C

4-Methyl-7-(phenylmethyl)-4,7-diazaspiro[2.5]octane-5,8-dione (1.535 g, 6.284 mmol) was dissolved in THF (100 mL) and the mixture was cooled to 0° C. Borane-THF complex (25.13 mL, 25.13 mmol) was added portionwise over 10 min. The mixture was heated to 60° C. for 4 h and was then checked by LCMS. If greater than 15% of the starting material remained, an additional portion of Borane-THF complex (12.56 mL, 12.56 mmol) was slowly added, and the reaction was allowed to stir for an additional 45 min. When the reaction was complete as determined by LCMS, the reaction mixture was cooled to room temperature. 1N HCl (25 mL) was added, and the mixture was heated to 80° C. for 1 h. The reaction mixture was then cooled to room temperature, and 6 N aq. NaOH was added to adjust the pH to 14. The mixture was extracted with CH2Cl2 (3×50 mL). The combined organic layers were dried over Na2SO4, filtered, and concentrated in vacuo. The resulting crude product was purified via reverse phase HPLC to provide 4-methyl-7-(phenylmethyl)-4,7-diazaspiro[2.5]octane (1.43 g, 94%). LCMS: (M+H)+:217.2.

1. additionBorane-THF complex (25.13 mL, 25.13 mmol) was added portionwise over 10 min
2. temperatureThe mixture was heated to 60° C. for 4 h
3. additionan additional portion of Borane-THF complex (12.56 mL, 12.56 mmol) was slowly added
4. temperaturethe reaction mixture was cooled to room temperature
5. temperaturethe mixture was heated to 80° C. for 1 h
6. temperatureThe reaction mixture was then cooled to room temperature
7. extractionThe mixture was extracted with CH2Cl2 (3×50 mL)
8. dry with materialThe combined organic layers were dried over Na2SO4
9. filtrationfiltered
10. concentrationconcentrated in vacuo
11. customThe resulting crude product was purified via reverse phase HPLC

ORD record

ord-13079190020042548a7f45aeabdfde72

Source dataset

uspto-grants-2011_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07893056B2