Deamination oftrans-2-Methyl- andtrans-2-Phenylcyclopropylamines

Abstract

The deaminations of trans-2-methyl- and 2-phenylcyclopropylamine hydrochlorides in acetic acid solution have been examined. A major product in each case was an allylic chloride, and the amount of chlorides increased when the chloride ion concentration was increased. With the methyl-substituted amine, increasing the chloride ion concentration changed the major chloride product from crotyl chloride to methallyl chloride. The addition of lithium perchlorate led to a reduction in the amount of chlorides formed. These results indicate that an ion pair is involved in the reaction. The deamination of the related open chain amines gave only small amounts of chlorides. B3LYP/6-31G* calculations found cyclopropyldiazonium chloride to prefer to have the chloride ion over the cyclopropyl ring. The transition state was located, and when followed down to products, allyl chloride was found. Similar calculations for the methyl-substituted series led to crotyl chloride from the ion pair with one chloride ion and to methallyl chloride from the ion-triplet with two chloride ions. The deaminations of the corresponding nitrosoureas in basic methanol also were studied. The products were the expected ethers. The addition of azide ion led to azides that were largely formed by initial reaction with the diazonium ion to give a pentazene that lost nitrogen to give the azide. However, some of the azide was formed by an SN2 displacement.