Acetic Acid → Heptanal, 2-methylene-

Participants

Reaction Conditions

Reaction Steps

A 3-L three-neck flask fitted with an overhead stirrer and a condenser was charged with di-n-butylamine (33 g) and acetic acid (31 g). Formaldehyde solution in water (500 mL, 33%) was added and the resulting solution was heated to 50° C. with stirring. Heptanal (500 g) was fed in over about 1.5 hours. A slight exotherm was noticed during the feed. GC analysis showed the consumption of heptanal and the production of 2-methylene heptanal, and a conversion rate of about 95% after the feed was completed. The reaction was cooled to room temperature and the reaction mixture was poured into a separatory funnel and washed once with HCl solution (5%). The organic layer was then washed once with saturated sodium carbonate to provide crude 2-methylene heptanal (553 g), which was loaded into a 2-L stainless steel pressure reactor along with dicyclopentadiene (343 g). The pressure reactor was sealed and heated to 170° C. with stirring for two hours. The reaction was then cooled to room temperature. The resulting crude product was purified by distillation to yield 2-pentylbicyclo[2.2.1]hept-5-ene-2-carbaldehyde (217 g).

Provenance & Evidence