HCID 86740358, compound → HCID 86740356, compound

Participants

Reaction Steps

In a manner analagous to Example 2, a solution of 3.42 g of (Z)-[5-(4-methoxy-2,3,6-trimethylphenyl)-3-methyl-2-penten-4-ynyl]triphenylphosphonium bromide in 240 ml of methanol was hydrogenated in the presence of 1.8 g of palladium/barium sulphate (5%). 188 ml of hydrogen were taken up within 2 hours. The crude product (3.4 g) of (2Z,4Z)-[5-(4-methoxy-2,3,6-trimethylphenyl)-3-methyl-2,4-pentadienyl]triphenylphosphonium bromide (chemical yield 54.6% in accordance with HPLC) obtained after filtration and evaporation was dissolved in 20 ml of methylene chloride and crystallized by the dropwise addition of 50 ml of ethyl acetate while stirring. The suspension was left to stand at 0° C. overnight and filtered. The crystals were washed with a small amount of ethyl acetate/methylene chloride (volume ratio 5:1) and dried at room temperature/0.01 mbar. There was thus obtained 1.0 g of 94.9% (2Z,4Z)-[5-(4-methoxy-2,3,6-trimethylphenyl)-3-methyl-2,4-pentadienyl]triphenylphosphonium bromide; m.p. 202°-205° C.

Provenance & Evidence