Benzyl Alcohol → Benzyl 5-bromopentanoate

Temperature

0 °C

To a dry, nitrogen purged 100 mL round bottomed flask was added benzyl alcohol (2.98 g, 0.027 mol), triethylamine (2.79 g, 0.027 mol) and CH2Cl2 (50 mL). The solution was stirred and cooled to 0° C. and 5-bromovaleryl chloride (5.00 g, 0.025 mol) added dropwise. A white suspension formed and this mixture was stirred at 0° C. for 0.5 h then warmed to rt over 1 h. After stirring at rt for 15 h, the suspension was poured into water (100 mL) and the phases separated. The aqueous layer was extracted with CH2Cl2 (1×100 mL) and the combined CH2Cl2 layers were dried over Na2SO4. Filtration and concentration produced a light brown suspension, which was diluted with EtOAc (50 mL) and then re-filtered. After concentration, the resulting amber oil was chromatographed on silica gel using 10% EtOAc in hexanes to give 6.79 g (100%) of Preparation 12 as a clear, colorless oil. Rf=0.80 (SiO2, 50% EtOAc in hexanes). 1H NMR (500 MHz, CDCl3): δ=7.33 (m, 5H), 5.11 (s, 2H), 3.38 (t, J=6.5 Hz, 2H), 2.38 (t, J=7.0 Hz, 2H), 1.88 (m, 2H) and 1.79 (m, 2H).

1. customTo a dry, nitrogen purged 100 mL round bottomed flask
2. customA white suspension formed
3. stirringthis mixture was stirred at 0° C. for 0.5 h
4. temperaturethen warmed to rt over 1 h
5. stirringAfter stirring at rt for 15 h
6. customthe phases separated
7. extractionThe aqueous layer was extracted with CH2Cl2 (1×100 mL)
8. dry with materialthe combined CH2Cl2 layers were dried over Na2SO4
9. filtrationFiltration and concentration
10. customproduced a light brown suspension, which
11. filtrationre-filtered
12. concentrationAfter concentration
13. customthe resulting amber oil was chromatographed on silica gel using 10% EtOAc in hexanes
14. customto give
15. custom6.79 g (100%) of Preparation 12 as a clear, colorless oil

ORD record

ord-2ace6dc7e9e74de4b9046eada3e07df1

Source dataset

uspto-grants-2009_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07550458B2