Highly Chlorinated Systems by Ring Closure Reactions

✍ Scribed by Dr. Gunther Beck (lecturer); Dr. Helmut Heitzer; Prof. Dr. Hans Holtschmidt

• Publisher: John Wiley and Sons
• Year: 1974
• Tongue: English
• Weight: 116 KB
• Volume: 13
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.197402101

✦ Synopsis

Cyanornethylated and cyanoethylated secondary aliphatic amines ( I ) are converted by chlorination at 20-50 C cia isolable dichloro derivatives (2) into highly reactive non-isol-aminopropionitrile], or conjugated bicycles [e. 9. (7) from 3-pyrrolidinopropionitrile].

Still further chlorination between 100 and 200 C leads to cleavage of onr of the three N--C bonds marked A, B, and C in (4) (special case of "dealkylating high-temperature chlorination" of amines). Obviously the N-C bonds that are cleaved are those which lead to formation of the thermodynamically most stable end products. X' Cleavage at "A" usually occurs when n = I, and affords pyrimia-chloroalkylamines f 3 ) , which 'yciize f4/ that are dines, ( , , 9-4,5,6-trichloropyrimidine [from (6 )] or ( 8 ) (from 3 ~m o r p ~o ~~n o p r o p ~o n ~~r ~~e ) ~ When 12= 0, cleavage occurs at into fiveand six-membered ring "B" and leads to perchlorodiazaalkadienes, e. g. (9) [from very sensitive to hydrolysis.