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

Temperature

-20 °C

10.0 g (38.4 mmol) of methyl 2,4-dibromobutanoate in 100 ml of dry THF at −20° C. was added dropwise 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 record

ord-b09d96c1fd2341b19c963d162914d05b

Source dataset

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09061995B2