Bromide ion → 4-Bromo-3-(trifluoromethoxy)benzaldehyde

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Reaction Steps

In Scheme 31 are shown 2 methods that may be used for the synthesis of 4-bromo-3-(trifluoromethoxy)benzaldehyde or 4-chloro-3-(trifluoromethoxy)benzaldehyde. Method 1: Commercially available 4-amino-3-(trifluoromethoxy)benzoic acid can be converted into the ester followed by a Sandmeyer reaction, described in Scheme 30, to provide the bromide or chloride. Reduction of the ester provides 4-bromo-3-(trifluoromethoxy)benzyl alcohol. The alcohol can be oxidized to the aldehyde to give the desired substituted benzaldehyde. Method 2: Commercially available 4-bromo-2-(trifluoromethoxy)aniline can be protected on the amino group with a suitable amino protecting groups well known to those skilled in the art of organic chemistry. The bromine can then be converted to the lithio or magnesio derivative and reacted directly with dimethylformamide to provide the 4-aminoprotected-3-(trifluoromethoxy)benzaldehyde derivative. Removal of the N-protecting group followed by protection of the aldehyde provides 4-(1,3-dioxolan-2-yl)-2-(trifluoromethoxy)aniline. Conversion of the amine to a bromide via the Sandmeyer method of Scheme 30 followed by hydrolysis of the dioxolane provides 4-bromo-3-(trifluoromethoxy)benzaldehyde.

Provenance & Evidence