Methanol → [(E)-3-(4-formyl-3,5-dimethylphenyl)-allyl]-phosphonic acid diethyl ester

Participants

Reaction Conditions

Reaction Steps

To a suspension of 4-amino-2,6-dimethylbenzaldehyde (3.0 g, 20.1 mmol) (Example 1-60, step B) in enough 42% HBF4 to be stirred at 0° C. was added a solution of NaNO2 (1.39 g, 20.1 mmol) in water (10 ml) slowly. After 30 min at 0° C., MeOH (50 mL) was added and followed by Pd(OAc)2 (677 mg) and diethyl allylphosphonate (5.38 g, 30.2 mmol). The reaction mixture was heated at 80° C. for 30 min and the suspension was filtered through Celite, washed with CH2Cl2. The filtrate was extracted with CH2Cl2 and the combined organic layers were washed with water, brine, dried with MgSO4, and filtered. The solvent was removed under reduced pressure and the residue was purified by flash chromatography using a gradient of heptane/EtOAc (10:1 to 5:1 then followed by 100% EtOAc) to give the title compound as a light yellow oil. MS: m/z 311 (M+1).

Provenance & Evidence