1-Methoxy-1,3,5-cycloheptatriene → 7-Methoxycycloheptatriene

Participants

Reaction Steps

An improved multi-step process for synthesizing the liquid irritant 1-methoxycycloheptatriene through the steps of reacting cycloheptatrienyl tetrafluoroborate in aqueous solution with methanol and sodium bicarbonate to produce 7-methoxycycloheptatriene, thermally isomerizing the 7-methoxycycloheptatriene to 3-methoxycycloheptatriene by heating at 150° C. for 2 hours and isomerizing the 3-methoxycycloheptatriene to 1-methoxycycloheptatriene by acid, catalyzed rearrangement employing methanolic hydrogen chloride followed by neutralization with sodium bicarbonate, filtration and fractional distillation to give the final product the improvement comprising the step of utilizing a polymerization/condensation inhibitor to increase the overall yield and purity of the 1-methoxycycloheptatriene product. The overall yield and purity of the product can further be increased through the step of conducting the thermal isomerization of 7-methoxy to 3- and 1-methoxycycloheptatriene at 180° C. under reduced pressure, e.g., by heating in a sealed reactor.

Provenance & Evidence