Premium
Reaction of sulfene and dichloroketene with open‐chain N,N ‐disubstituted α‐aminomethyleneketones. Synthesis of 4‐dialkylamino‐3,4‐dihydro‐5,6‐dimethyl‐1,2‐oxathiin 2,2‐dioxides and of 6,(5)(di)alkyl‐3‐chloro‐4‐methylphenylamino‐2 H ‐pyran‐2‐ones
Author(s) -
Bargagna Alberto,
Sche Pietro,
Bondavalli Francesco,
Longobardi Mario
Publication year - 1980
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.5570170107
Subject(s) - chemistry , yield (engineering) , alkyl , cycloaddition , pyran , derivative (finance) , medicinal chemistry , stereochemistry , organic chemistry , catalysis , materials science , economics , financial economics , metallurgy
Cycloaddition of sulfene to N,N ‐disubstituted 4‐amino‐3‐methyl‐3‐buten‐2‐ones (III) occurred in fair to good yield only in the case of aliphatic N ‐substitution to give 4‐dialkylamino‐3,4‐dihydro‐5,6‐dimethyl‐1,2‐oxathiin 2,2‐dioxides, whereas N,N ‐disubstituted 1‐amino‐1‐penten‐3‐ones (II) did not react at all. Cycloaddition of dichloroketene to II, III and N,N ‐disubstituted 4‐amino‐3‐buten‐2‐ones occurred only in the case of the methylphenylamino derivative, giving in good to moderate yield 6,(5)(di)alkyl‐3,3‐dichloro‐3,4‐dihydro‐4‐methylphenylamino‐2‐ H pyran‐2‐ones, which were dehydrochlorinated with DBN to 6,(5)(di)alkyl‐3‐chloro‐4‐methylphenylamino‐2 H ‐pyran‐2‐ones.