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Reaction of ketenes with N,N ‐Disubstituted 2‐Aminomethylenecycloalkanones III. Synthesis of N,N ‐Disubstituted 3,3‐Diehloro‐4‐amino‐5,6‐polymethylene‐3,4‐dihydro‐α‐pyrones
Author(s) -
Bignardi G.,
Fvangelisti F.,
Sche P.,
Bargagna A.
Publication year - 1972
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570090520
Subject(s) - chemistry , adduct , cycloaddition , nitrogen atom , medicinal chemistry , pyrone , stereochemistry , organic chemistry , ring (chemistry) , catalysis
The reaction of dichloroketene with N,N ‐Disubstituted 2‐aminomethylenecyclopentanones, cyclohexanones, cycloheptanones and cyclooctanones gave the 1,4‐cycloadducts, namely N,N ‐Disubstituted 3,3‐dichloro‐4‐amino‐5,6‐polymethylene‐3,4‐dihydro‐α‐pyrones. The structures of these products were determined by uv, ir and nmr spectral data, as well as by dehydrochlorination of the adduct, 3,3‐dichloro‐4‐diphenylamino‐5,6‐tetramethylene‐3,4‐dihydro‐α‐pyrone, which led to 3‐chloro‐4‐diphenylamino‐5,6‐tetramethylene‐α‐pyrone. The by‐product of the cycloaddition reaction was the N,N ‐Disubstituted dichloroacetamide, the formation of which varies according to the substituents on the nitrogen atom.