Dimethylformamide → HCID 21278869, Verbindung
Reaktionsgleichung
[O:1]=[C:2]1[N:6]([CH2:7][C:8]([OH:10])=O)[C:5]2[CH:11]=[CH:12][CH:13]=[CH:14][C:4]=2[S:3]1.O[N:16]1[C:20](=O)[CH2:19][CH2:18][C:17]1=O.C[N:24](C)C=O>>[N:16]1([C:8]([CH2:7][N:6]2[C:5]3[CH:11]=[CH:12][CH:13]=[CH:14][C:4]=3[S:3][C:2]2=[O:1])=[O:10])[CH2:20][CH2:19][NH:24][CH2:18][CH2:17]1Komponenten
4
Versuchsvorschrift
To an ice-cooled solution of 2-oxo-3-benzothiazolineacetic acid [J. Prakt. Chem. 27 (3-4), 220-4 (1965); 8.1 g] and N-hydroxysuccinimide (5.4 g) in N,N-dimethylformamide (50 ml) was gradually added N,N-dicyclohexylcarbodiimide (9.6 g), and the mixture was stirred for an hour at ambient temperature. The dicyclohexylurea that precipitated from the reaction mixture was filtered off. To a stirred solution of piperazine (16.7 g) in N,N-dimethylformamide (200 ml) was added dropwise the filtrate for a period of 40 minutes below 20° C. The final mixture was stirred for 3.5 hours at ambient temperature and then filtered. The filtrate was concentrated under reduced pressure. The residue was dissolved in 2N hydrochloric acid and the solution was washed with chloroform. The aqueous layer was adjusted to pH 9 with an aqueous solution of sodium hydrogen carbonate, and the turbid solution was extracted with chloroform (80 ml×3). The extracts were combined and dried over magnesium sulfate. After evaporation of the solvent, 3-[(1-piperazinyl)carbonylmethyl]-2-benzothiazolinone (9.50 g) was obtained as white powders.