Abstract: Yield and assay (purity) improvements in the reaction of bromine and the Diels-Alder addition product of maleic anhydride and a conjugated diene in the presence of a nitrogenous acid acceptor are realized in the instant process. The heating time after completion of bromine addition is increased to more completely eliminate hydrogen bromide from the reaction medium and thereby drive the reaction to completion. Also, the type of catalyst selected for use is one which will yield a phthalimide by-product impurity having a boiling point which differs enough from the boiling point of the desired product to allow for distillative separation of the impurity and desired product.

Abstract: There is disclosed a process for the production of cinnamic acid wherein different catalysts are used. Suitable catalysts include Lewis acids, transition metal derivatives of acetic acid and halides of alkali metals.

Abstract: Saponifiable impurities are removed from pyrethroid intermediates represented by the structure ##STR1## wherein R represents an alkyl radical having from 1 to about 30 carbon atoms and wherein X.sup.1 and X.sup.2 each represent a halogen by selectively saponifying said impurities by reaction with an aqueous base.