Mono- and Difluoromethyl Amino Acids

Preparation of a-monofluoromethyl amino acids is not easy. Indeed, although the amino acids can easily be hydroxymethylated, substitution of the hydroxyl by a fluorine atom is not always easy (SF4, DAST). On the other hand, preparation of monofluoroketones (substrates of the Strecker reaction) involves the use of highly toxic fluoroacetonitrile. °  

The ban of halogenofluoromethanes (halons) for environmental reasons may reduce the benefit of this straightforward method, at least on the industrial level. Difluoromethyl ornithine (DFMO) was prepared industrially by this path (alkylation with CHCIF2). New approaches are currently the focus of research in order to restart its production. 

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Figure 5.26 Mono- and difluoromethyl amino acids from malonates.

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