[CH3:1][S:2][C:3]1[S:4][C:5]([C:21](O)=[O:22])=[C:6]2[C:20]=1[C:10]1[N:11]=[C:12]([C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=3)[S:13][C:9]=1[CH2:8][CH2:7]2.[C:24](Cl)(=O)[C:25](Cl)=O.C[N:31](C)C=O>O1CCCC1>[CH2:24]([NH:31][C:21]([C:5]1[S:4][C:3]([S:2][CH3:1])=[C:20]2[C:10]3[N:11]=[C:12]([C:14]4[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=4)[S:13][C:9]=3[CH2:8][CH2:7][C:6]=12)=[O:22])[CH3:25]4,5-Dihydro-8-methylthio-2-phenylthieno[3,4-e]benzothiazole-6-carboxylic acid (0.43 g) was suspended in tetrahydrofuran (15 ml); oxalyl chloride (0.23 g) and then N,N-dimethylformamide (6 μl) were added. After this mixture was stirred at room temperature for 2 hours, it was concentrated under reduced pressure. The residue was suspended in tetrahydrofuran (5 ml) and cooled with ice; a 70% aqueous solution of ethylamine (4.0 ml) was added. After the reaction mixture was stirred at room temperature for 1 hour, it was poured over water (150 ml) and extracted with ethyl acetate-tetrahydrofuran (3:1, v/v). The organic layer was washed with water and dried (MgSO4), after which the solvent was distilled off to yield N-ethyl-4,5-dihydro-8-methylthio-2-phenylthieno[3,4-e]benzothiazole-6-carboxamide (0.35 g, 76%), which was then recrystallized from chloroform-ethanol. Yellow needles. Melting point 211-212° C.
読み込み中…
