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Halogen‐ und Pseudohalogen‐substituierte Penta‐ und Tetramethylcyclopentadine
Author(s) -
Jutzi Peter,
Schwartzen KarlHeinz,
Mix Andreas
Publication year - 1990
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19901230431
Subject(s) - cyclopentadiene , chemistry , halogen , halide , alkyl , medicinal chemistry , halogenation , organic chemistry , catalysis
Halogen‐ and Pseudohalogen‐Substituted Penta‐ and Tetramethylcyclopentadienes The alkyl halides 5‐bromo‐1,2,3,4,5‐pentamethyl‐1,3‐cyclopentadiene ( 2 ), 5‐iodo‐1,2,3,4,5‐pentamethyl‐1,3‐cycloentadiene ( 3 ), and 5‐bromo‐1,2,3,4‐tetramethyl‐1,3‐cyclopentadiene ( 8 ) are formed in good yields by treatment of pentamethylcyclopentadienyllitium ( 1 ) and tetramethylcyclopentadienyllithium ( 7 ), respectively, with the corresponding cyanogen halides. Reaction of 1 with cyanogen chloride or cyanogen leads to 5‐cyano‐1,2,3,4,5‐pentamethyl‐1.3‐cyclopentadiene ( 4 ). Treatment of 1 with thiocyanogen yields 5‐isothiocyanato‐1,2,3,4,5‐pentamethyl‐1,3‐cyclopentadiene ( 5 ). 5‐Chloro‐1,2,3,4,5‐pentamethyl‐1,3‐cyclopentadiene ( 6 ) is obtained fro 1 and a mixture of tetrachloromethane and triphenylphosphane. Analogously, the halides 2 and 3 can be synthesized by the reaction of 1 with a mixture of triphenylphosphane and tetrabromomethane or tetraiodomethane. Treatment of 7 with tetrachloromethane and triphenylphosphane yields a mixture of isomers of chlorotetramethylcyclopentadiene.