The bromination of naphthalene V. A theoretical treatment of the non‐catalytic mono‐bromination of gaseous naphthalene above 300°

Abstract In the non‐catalytic bromination of gaseous naphthalene below 300° the main product is α‐monobromonaphthalene. Between 300° and 500° the ratio of β‐bromonaphthalene to α‐bromonaphthalene increases rapidly with the temperature. At still higher temperatures this ratio remains constant and is approximately equal to unity. It is assumed that the bromination of naphthalene proceeds as an electrophylic substitution at relatively low temperatures, whereas at high temperatures a radical substitution develops. A formula is derived which gives satisfactory agreement with the experimental values of the ratio of β‐ to α‐bromonaphthalene.