1-Aminocyclopropanecarboxylic acid diazotization

Diazotization of cyclopropylamines in the presence of a chloride source is also a useful method for the preparation of some chlorocyclopropanes. When 1-aminocyclopropanecarboxylic acid was treated with nitrous acid in the presence of potassium chloride, 1-chlorocyclopropanecarb-oxylic acid (9) was isolated in 75% yield. Similarly, a modified Sandmeyer reaction of 7-ami-nocyclopropanoacenaphthylene (10) yielded 7-chlorocyclopropanoacenaphthylene (11). ... 

Diazotization of 1-aminocyclopropanecarboxylic acid with nitrous acid in the presence of lithium bromide gave 1-bromocyclopropanecarboxylic acid (16) in 75% yield. ... 

Diazotization of 1-aminocyclopropanecarboxylic acid in the presence of ethanethioic S-acid proceeded uneventfully and gave l-(sulfanylacetoxy)cyclopropanecarboxylic acid in 60% isolated yield.C—Si bond cleavage took place when cyclopropyltrimethylsilane and trimethyl-silyl chlorosulfonate were refluxed in cyclohexane giving trimethylsilylcyclopropanesulfonate in 70% yield. 

Diazotization of 1-aminocyclopropanecarboxylic acid in the presence of a carbon nucleophile gives a-substituted cyclopropanecarboxylic acids in moderate yields. When this amino acid was allowed to react with sodium nitrite in trifluoroacetic acid or with nitrosyl tetrafluoroborate in acetonitrile in the presence of potassium cyanide, 1-cyanocyclo-propanecarboxylic acid (1) was obtained in 64% yield. Similarly, l-(3-trimethylsilylprop-yl)cyclopropanecarboxyIic acid (2) was isolated in 30% yield when diazotization was carried out in the presence of allyl trimethylsilane. ... 

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