Application
1-Chloro-N,N,2-trimethylpropenylamine (TMCE) is used to mild halogenation of alcohols and acids under neutral conditions; conversion of N-protected amino acids into
peptides without racemization; coupling of acids and allylic alcohols with organometallics; [2 + 2]
cycloaddition synthons, more reactive than dimethylketene.
Preparation
1-chloro-N,N,2-trimethylpropenylamine is conveniently prepared by the reaction of N,N,2-
trimethylpropanamide with Phosgene followed by dehydrochlorination of the intermediate α-chloroiminium
chloride (eq 1).
[1,2] Recent unpublished results of our laboratory have shown that Phosphorus Oxychloride or dior triphosgene can also be used for the preparation of TMCE.
storage
1-chloro-N,N,2-propenylamines are thermally
stable. It must be transferred in the absence of moisture and stored under nitrogen in sealed tubes. In spite of
these precautions, light precipitates sometimes may form. 1-Iodo-N,N,2-trimethylpropenylamine is less stable and
should be used when freshly prepared.
References
1. Ghosez, L.; Marchand-Brynaert, J. In Advances in Organic Chemistry; Raphael, R. A.; Taylor, E. C.; Wynberg, H.,
Eds.; Interscience: New York, 1976; Part 1, pp 421-523.
2. (a) Haveaux, B.; Dekoker, A.; Rens, M.; Sidani, A. R.; Toye, J.; Ghosez, L. OS 1979, 59, 26. (b) Ghosez, L.; Koch, I.
Swiss Pat. 681 623A, 1993.
