Diethyl Ether → 2-Cyclopropyl-6-methyl-benzaldehyde

Temperature

60 °C

This compound was prepared using methodology described in Synthesis 1999, 2138-2144. A solution of cyclopropylmagnesium bromide was first prepared by dropwise addition of a solution of 3.06 ml (38.2 mmol) cyclopropyl bromide in 15 ml diethyl ether to 0.93 g (38.2 mmol) magnesium turnings followed by heating at reflux for 5 min. Meanwhile, to a solution of 3.20 g (15.3 mmol) butyl-[1-(2-chloro-6-methyl-phenyl)-meth-(E)-ylidene]-amine in 30 ml tetrahydrofuran at 0° C. was added 0.19 g (1.53 mmol) manganese(II) chloride. The freshly prepared solution of cyclopropylmagnesium bromide in diethyl ether was then added dropwise, during which the temperature of the reaction mixture rose to 50° C. After the addition was complete, the reaction mixture was heated at 60° C. for 16 h. The reaction mixture was then cooled to room temperature and quenched by dropwise addition of water before being diluted with ethyl acetate. The mixture was then washed sequentially with water and with saturated brine. The phases were separated and the organic phase was dried over Na2SO4, filtered and concentrated in vacuo. The residue was purified by flash chromatography (silica gel, ethyl acetate/heptane gradient) to afford 1.60 g (65%) of the title compound as a yellow oil. 1H-NMR (CDCl3): 0.75 (2H, m, CH2), 1.04 (2H, m, CH2), 2.39 (1H, m, CH), 2.59 (3H, s, CH3), 7.07 (1H, t, ArH), 7.33 (2H, m, ArH), 10.9 (1H, s, CHO).

1. customThis compound was prepared
2. customdescribed in Synthesis 1999, 2138-2144
3. temperatureby heating
4. temperatureat reflux for 5 min
5. customrose to 50° C
6. additionAfter the addition
7. temperatureThe reaction mixture was then cooled to room temperature
8. customquenched by dropwise addition of water
9. additionbefore being diluted with ethyl acetate
10. washThe mixture was then washed sequentially with water and with saturated brine
11. customThe phases were separated
12. dry with materialthe organic phase was dried over Na2SO4
13. filtrationfiltered
14. concentrationconcentrated in vacuo
15. customThe residue was purified by flash chromatography (silica gel, ethyl acetate/heptane gradient)

ORD record

ord-f4c40aff964e405d8d8320de45e30c41

Source dataset

uspto-grants-2011_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07875645B2