Carbon Dioxide → 3-Fluoro-p-toluic acid

Beteiligte Stoffe

Reaktionsschritte

2.96 gms. of 3-fluoro-4-(5-pentyl-1,3-dioxan-2-yl)-benzoic acid (prepared from 2-fluoro-4-bromotoluene by reaction with magnesium according to Grignard and reaction with carbon dioxide giving 3-fluoro-4-methyl-benzoic acid, esterification thereof with ethanol/sulfuric acid giving ethyl 3-fluoro-4-methyl-benzoate, bromination by bromine or N-bromo-succinimide giving ethyl 3-fluoro-4-bromomethylbenzoate, oxidation by dilute nitric acid giving 3-fluoro-terephthalic aldehydic acid and ketalization thereof with 2-pentyl-propane-1,3-diol) and 2.0 gms. of SOCl2 are boiled for 1 hour, then evaporated and the crude acid chloride thus obtained is dissolved in 20 ml of toluene and then 1.5 ml of pyridine and 1.10 gms. of 4-cyano-phenol are added and then boiled for two hours. After separation the organic phase is washed with water, dried over sodium sulfate and evaporated leaving behind 4-cyanophenyl 3-fluoro-4-(5-pentyl-1,3-dioxan-2-yl)-benzoate.

Herkunft & Nachweise