Low-temperature depolymerization of nylon-6 and other polyamides mediated by boron-based Lewis acids.

An efficient depolymerization of nylon-6 to 6-aminocaproic acid hydrochloride (6ACA·HCl) in >99% yield is reported. The reaction proceeds under mild conditions and generates no detectable organic by-products, thereby eliminating the need for tedious purification. The obtained 6-ACA·HCl is a commercially valuable compound that can be converted to ε-caprolactam in 78% yield.