Tetrahydrofuran → Methyl 2-(acetylthio)-4-bromobutanoate

Temperatur

-20 °C

10.0 g (38.4 mmol) of methyl 2,4-dibromobutanoate in 100 ml of dry THF at 20° C. was added drop wise the mixture of 2.75 ml (38.5 mmol) of thiolacetic acid in 8.5 ml (48.9 mmol) of DIPEA and 50 ml of dry THF in 1.5 hour. After stirring overnight at −20° C. then 0° C. for 2 hours under Ar, the mixture was concentrated, diluted with EtAc/Hexane, washed with 1.0 M NaH2PO4, dried over MgSO4, filtered, evaporated, and SiO2 chromatographic purification (1:12 to 1:10 EtAc/Hexane) to afford 9.5 g (96%) of the title compound. 1H NMR (CDCl3) 4.38 (1H, t, J=7.1 Hz), 3.74 (s, 3H), 3.40 (m, 2H), 2.57˜2.47 (m, 1H), 2.37 (s, 3H), 2.36˜2.21 (m, 1H); 13C NMR 193.24, 171.36, 53.15, 44.45, 34.67, 30.46, 29.46; MS m/z+276.9 (M+Na), 278.9 (M+2+Na)

1. wait0° C. for 2 hours under Ar
2. concentrationthe mixture was concentrated
3. additiondiluted with EtAc/Hexane
4. washwashed with 1.0 M NaH2PO4
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. customevaporated
8. customSiO2 chromatographic purification (1:12 to 1:10 EtAc/Hexane)

ORD-Eintrag

ord-c54f375f643f4e4da28943cfdc5096d9

Quelldatensatz

uspto-grants-2012_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08236319B2