Acetaldehyde → HCID 28169010, compound

Temperature

40 °C

NaCNBH3 (1.60 g, 24.2 mmol) was added in batches to a chilled (˜15° C.) water/MeOH (12 mL each) solution of (S)-4-amino-2-(tert-butoxycarbonylamino) butanoic acid (2.17 g, 9.94 mmol). A few minutes later acetaldehyde (2.7 mL, 48.1 mmol) was added drop-wise over 2 min, the cooling bath was removed, and the reaction mixture was stirred at ambient condition for 3.5 hr. An additional acetaldehyde (2.7 mL, 48.1 mmol) was added and the reaction was stirred for 20.5 hr. Most of the MeOH component was removed in vacuo, and the remaining mixture was treated with concentrated HCl until its pH reached ˜1.0 and then heated for 2 hr at 40° C. The volatile component was removed in vacuo, and the residue was treated with 4 M HCl/dioxane (20 mL) and stirred at ambient condition for 7.5 hr. The volatile component was removed in vacuo and the residue was purified with Dowex® 50WX8-100 ion-exchange resin (column was washed with water and the compound was elated with dilute NH4OH, prepared from 18 ml of NH4OH and 282 ml of water) to afford intermediate (S)-2-amino-4-(diethylamino)butanoic acid as an off-white solid (1.73 g).

1. customthe cooling bath was removed
2. stirringthe reaction was stirred for 20.5 hr
3. customMost of the MeOH component was removed in vacuo
4. additionthe remaining mixture was treated with concentrated HCl until its pH
5. customThe volatile component was removed in vacuo
6. additionthe residue was treated with 4 M HCl/dioxane (20 mL)
7. stirringstirred at ambient condition for 7.5 hr
8. customThe volatile component was removed in vacuo
9. customthe residue was purified with Dowex® 50WX8-100 ion-exchange resin (column
10. washwas washed with water
11. customprepared from 18 ml of NH4OH and 282 ml of water)

ORD record

ord-942979ac8dec41d691263d5cea8de22f

Source dataset

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08383094B2