Isobutyraldehyde → (4S)-4-Isobutyl-2-isopropyloxazolidine

A solution of (1S)-1-(hydroxymethyl)-3-methylbutylamine (Method B1b; 152 g, 1.3 mol) and isobutyraldehyde (118 mL, 1.3 mol, 1.0 equiv.) in toluene (1.5 L) was heated at the reflux temp. until the theoretical amount of water had been collected in a Dean-Stark trap (23.4 mL). The reaction mixture was concentrated by distillation to approximately 700 mL. The resulting mixture was cooled to room temp. and was concentrated under reduced pressure to a constant weight to give (4S)-2-isopropyl-4-isobutyl-1,3-oxazolidine as a pale yellow oil (223 g, 100%): 1H NMR (CDCl3) δ0.88-0.99 (m, 12H), 1.18-1.35 (m, 1H), 1.42-1.56 (m, 1H), 1.61-1.79 (m, 4H), 3.08 (t, J=7.4 Hz 1H), 3.20-3.34 (m, 1H), 3.85 (t, J=7.4 Hz, 1H), 4.18 (dd, J=7.3, 3.4 Hz, 1H).

1. customuntil the theoretical amount of water had been collected in a Dean-Stark trap (23.4 mL)
2. concentrationThe reaction mixture was concentrated by distillation to approximately 700 mL
3. temperatureThe resulting mixture was cooled to room temp.
4. concentrationwas concentrated under reduced pressure to a constant weight

ORD record

ord-71ca128157574f968e5f7a17729a53c5

Source dataset

uspto-grants-2002_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06353006B1