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1, 5, 6, 7‐Tetrahydro‐2H‐[1,4]diazepin‐5,7‐dione aus Malonimiden und 3‐Dimethylamino‐2,2‐dimethyl‐2H‐azirin
Author(s) -
Scholl Bernhard,
Bieri Jost H.,
Heimgartner Heinz
Publication year - 1978
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19780610830
Subject(s) - chemistry , sodium borohydride , imidazole , diazepine , derivative (finance) , medicinal chemistry , amine gas treating , ring (chemistry) , ethanol , sodium ethoxide , stereochemistry , organic chemistry , catalysis , financial economics , economics
1, 5, 6, 7‐Tetrahydro‐2H‐[1, 4]diazepin‐5, 7‐diones from Malonimides and 3‐Dimethylamino‐2, 2‐dimethyl‐2H‐azirine Reaction of the aminoazirine 1 with malonimides of type 7 in 2‐propanol at room temperature leads to the 1,4‐diazepine derivatives of type 9 ( Scheme 3 ). The structure of 6, 6‐diethyl‐3‐dimethylamino‐2,2‐dimethyl‐1,5,6, 7‐tetrahydro‐2H‐ [1,4] diazepin‐5, 7‐dione ( 9a ) has been proved by single crystal X‐ray analysis (Chapter 4). Reduction of the 7‐membered heterocycle 9a with sodium borohydride yields the perhydro‐[1,4]diazepin‐5, 7‐dione 10 , while 9a in ethanol at 60° undergoes a ring contraction to the 4 H‐imidazole derivative 11a ( Scheme 4 ): Mechanisms of these two reactions are discussed in comparison with previously reported reactions (Chapter 5).