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Reaktion von 3‐Dimethylamino‐2,2‐dimethyl‐2 H ‐azirin mit Barbitursäure
Author(s) -
Link Helmut,
Bernauer Karl,
Daly John J.,
Chaloupka Stanislav,
Heimgartner Heinz
Publication year - 1981
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.19810640108
Subject(s) - chemistry , barbituric acid , azirine , yield (engineering) , dimethyl formamide , alkylation , formamide , medicinal chemistry , ethanol , dimethyl sulfate , aqueous solution , nuclear chemistry , organic chemistry , catalysis , solvent , ring (chemistry) , materials science , metallurgy
Reaction of 3‐Dimethylamino‐2,2‐dimethyl‐2 H ‐azirine with Barbituric Acid The reaction of 3‐dimethylamino‐2,2‐dimethyl‐2 H ‐azirine (1) with barbituric acid (4) in dimethyl formamide at room temperature yields a mixture of several compounds. The two main products 5 and 6 have been isolated in 40 and 10% yield, respectively, and their structures established by X‐ray analysis. In Schemes 4–6 reaction mechanisms for the formation of 5 and 6 are postulated, the first step beeing either a C ‐ or an N ‐alkylation of barbituric acid. Reduction of 5 and 6 with NaBH 4 in ethanol at room temperature yields 6,6‐dimethyl‐1,5,6,7‐tetrahydro‐pyrrolo[2,3‐ d ]pyrimidin‐2,4(3 H )‐dione (7) and 3,3‐dimethyl‐2,3‐dihydro‐imidazo[1,2‐ c ]pyrimidin‐5,7(1 H , 6 H )‐dione (8) in 38 and 48% yield, respectively. Treatment of 6 with 3 N aqueous NaOH at room temperature gives 3,3‐dimethyl‐imidazo[1,2‐ c ]pyrimidin‐2,5,7 (1 H , 3 H , 6 H )‐trione (9) in 51% yield ( Scheme 3 ).