2.2.2- Trifluoroethyl isocyanate

Reaction of 2-cyanomethylpyridine with iV-(l-aryl-l-chloro-2,2,2-trifluoroethyl)-iV -(4-methylphenyl)carbodiimides, and with (1,1,2,2,2-pentachloro- and l,l-dichloro-2,2,2-trifluoroethyl)isocyanates or A-methoxycarbonyl-l,2,2,2-tetrachloro-, — l-chloro-2,2-trifluoroacetaldehyde imines afforded 3-aryl-4-cyano-l-(4-methylphenyl)imino-3-trifluoromethyl-2,3-dihydro-17/-pyrido[l,2-f]pyrimidines and 4-cyano-3-trichloro-, 4-cyano-3-trifluoro-17/-pyrido[l,2-4pyrimidin-l-ones, respectively <2004CHE47>. Refluxing 2-cyanomethylpyridine and iV-(l-aryl-l-chloro-2,2,2-trifluoroethyl)isocyanates in benzene furnished l-aryl-4-cyano-l-trifluoromethyl-l,2-dihydro-3//-pyrido[l,2-4pyrimidin-3-ones. However, when the solution of the isocyanate was added dropwise to the solution of 2-cyanomethylpyridine, and the reaction mixture was then treated with NEt at room temperature, the isomeric 3-aryl-4-cyano-3-trifluoromethyl-2,3-dihydro-l//-pyr-ido[l,2-dpyrimidin-l-ones were obtained. Reaction of l-(acetyl- and benzoylmethylene)-6,7-dimethoxy-l,2,3,4-tetra-hydroisoquinolines with PhCONCS yielded 1-acetyl-, 1 -benzoyl-9,10-dime thoxy-3-pheny 1-6,7-dihydro-2//-pyrimido[6,l- ]isoquinoline-2-thiones <2003SL2369>. 

In the thermal cyclization of 3-alkoxyphenyl A -(l-aryl-2,2,2-trifluoroethylidene)carbamates 287, obtained from 3-alkoxyphenols 285 and l-aryl-l-chloro-2,2,2-trifluoroethyl isocyanates 286, 2-aryl-2-trifluoromethyl-2,3-dihydro-477-l,3-benzoxazin-4-ones 290 were formed instead of the regioisomeric l,3-benzoxazin-2-ones 288 (Scheme 53). The formation of 290 was explained by a thermal isomerization of 287 involving a skeletal 1,3-rearrangement of the electron-rich aryloxy group to the azomethine carbon, which is electron deficient due to the electron-withdrawing CF3 group <2002JFC(116)97>. 

Trifluoromethyl)quinazolin-4(3//)-one (6) is formed quantitatively from a-azido-a-phenyl-/1-trifluoroethyl isocyanate (3) via a nitrene intermediate 4 which undergoes rearrangement to a-(A -phenylimino)- 8-trifluoroethyl isocyanate (5) followed by cyclization to 6 (cf. p 58). °... 

For use in plastics, this might require chain extension with diisocyanates, bisoxazolines, carbodiimides, bis(an-hydrides), and such. One use of the oligomers would be to form polyurethanes by reaction with isocyanates. The use of acid chlorides can be avoided if the polymers are made by ester exchange or made enzymatically, with compounds such as divinyl adipate. Poly(butylene sebacate) with a molecular weight of 46,400 has been made has been made from bis(2,2,2-trifluoroethyl)sebacate and 1,4-butane diol.150 One polyester with a molecular weight of 24,000 has been made by ester exchange from isosorbide and a... 

Of interest is the reaction of aryl isocyanates with NaBH4 and trifluoroacetic acid., V,A-Bis(2,2,2-trifluoroethyl)anilines are generated in good yields. ... 

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