1-Bromo-3-chloropropane → 4-(3-Chloro-propoxy)-2-methyl-benzaldehyde

Temperature

65 °C

4-(3-Iodo-propoxy)-2-methyl-benzaldehyde. 1-Bromo-3-chloropropane (5.03 g, 32.0 mmol, 1.0 equiv) was added to a solution of 2-methyl-4-hydroxybenzaldehyde (4.35 g, 32.0 mmol, 1.0 equiv) and K2CO3 (8.8 g, 64.0 mmol, 2.0 equiv) in acetonitrile (75 mL). The mixture was heated at 65° C. for 16 h, then cooled to rt and filtered through diatomaceous earth. The filtrate was concentrated and the residue was purified by column chromatography (silica gel, 10% ethyl acetate in hexanes) to afford 5.58 g (82%) of 4-(3-chloro-propoxy)-2-methyl-benzaldehyde. To a refluxing solution of 4-(3-chloro-propoxy)-2-methyl-benzaldehyde in acetone (100 mL), KI (58 g) was added portion wise over 3 d. The mixture was cooled to rt and water was added. The aqueous mixture was extracted three times with ethyl acetate and the combined extracts were dried (Na2SO4), filtered, and concentrated. The residue was purified by column chromatography (silica gel, 5% ethyl acetate in hexanes) to afford 6.13 g (77%) of the title compound. 1H NMR (400 MHz, CD3OD): 10.1 (s, 1H), 7.75 (d, J=8.6 Hz, 1H), 6.84 (dd, J=8.6, 2.5 Hz, 1H), 6.74 (d, J=2.2 Hz, 1H), 4.11 (t, J=5.8 Hz, 2H), 3.36 (t, J=6.7 Hz, 2H), 2.65 (s, 3H), 2.29 (m, 2H).

1. temperaturecooled to rt
2. filtrationfiltered through diatomaceous earth
3. concentrationThe filtrate was concentrated
4. customthe residue was purified by column chromatography (silica gel, 10% ethyl acetate in hexanes)

ORD record

ord-c56510e1429a4fa0a8da010b1882ee1b

Source dataset

uspto-grants-2008_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07432378B2