In:
Zeitschrift für Naturforschung B, Walter de Gruyter GmbH, Vol. 75, No. 9-10 ( 2020-11-26), p. 865-880
Abstract:
N,N,N′,N′ -Tetramethylurea diethylacetal reacts with CH 2 -acidic compounds as benzylcyanide, cyanoacetic acid derivatives malonodinitrile and nitromethane to give ketene aminals or ketene-O,N-acetales. Low polar solvents favour mostly the formation of ketenaminals. The yields of ketenaminals and ketene-O,N-acetals can be improved in some cases by addition of trimethylsilyldimethylamine. The reactions of the urea acetal with diethylmalonate, ore acetyl acetone, stops at the stage of the N , N ′, N″ -permethylated guanidinium salts with carbanionic counterions. The formation of bis(dimethylamino)methylene-diethylmalonate from the urea acetal and diethylmalonate can be initiated by addition of trimethylsilyldimethylamine/trimethylsilylcyanide. N,N,N′,N′,N″,N″- Hexamethylguanidinium cyanide is formed in the analogous reactions of the urea acetal with N,N- dimethylcyanacetamide or diethylsuccinate. The N,N′,N″ -Hexamethyl-guanidinium nitrite can be obtained from the urea acetal and nitropropane.
Type of Medium:
Online Resource
ISSN:
1865-7117
,
0932-0776
DOI:
10.1515/znb-2020-0072
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
2020
detail.hit.zdb_id:
2078109-X
detail.hit.zdb_id:
124635-5
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