Kaspar Bott

2,2-(n,n′-dimethyl-ethylendiamino)-ethylendiazonium-ion, ein diazonium-ion mit ungewöhnlichen eigenschaften

Abstract On treating with potassium methoxide at room temperature the donor-substituted ethylenediazonium ion 2 equilibrates with the stable α-diazoolefin 3 . At the same temperature the reaction of 2 with dilute methanesulfonic acid leads to a quantitative elimination of diazo nitrogen. Finally the 1,3-dipolar cycloaddition of 2 to dimethyl acetylenedicarboxylate affords the pyrazole derivative 5 in high yield.

Neue anwendungsmöglichkeiten des reformatzky-reagenz zur syntheses substituierter essigsäureethylester

Abstract When generated in dichloromethane, the Reformatzky reagent from ethyl bromoacetate can react with diphenylcholoromethane, 1-bromoadamantane and 1-phenylethyl chlorides to form the corresponding α -substituted ethyl acetates in excellent to good yields. The mechanism of these Reformatzky reactions is interpreted in terms of a carbocation as intermediate which originates from the interaction of the alkyl halide with the organozinc bromide.

Alkylation of α‐Diazoketones with Alkyldiazonium, Ions: Facile Synthesis of β‐Alkoxyethylenediazonium Salts

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1702. DOI:10.1002/anie.198217020