Methyl imidoesters

Endomethylene tetrahydrophthalic anhydride and the methyl derivate are also claimed for imide formation with aminoethanol [209]. The reaction of the endomethylene tetrahydrophthalic anhydride with hexahydro-p-aminobenzoic acid followed by a esterification with ethylene glycol and terephthalic acid yields an unsaturated imidoester curable by Michael addition with polyamines [210]. 

The methylation of 14, prepared via imidoester 13 [36], takes place exclusively at the amidic nitrogen. 

Preparation of Heavy-atom Derivatives.— The problems of X-ray analysis of large proteins have also stimulated further study of the preparation of specific heavy-atom derivatives. Perham and Thomas have investigated the use of the imidoester methyl-3-mercaptopropionimidate. This reacts selectively with the amino-groups of proteins. The thiol group introduced can be used for the attachment of heavy-atom derivatives. There is a specific reaction of the imidoester with one of the two lysine residues of the protein subunit of intact tobacco mosaic virus (Scheme 1). However, the reagent... 

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