Acetic Anhydride → 2-Ethoxymethyleneamino-3,5-dicarbethoxy-4,6-dihydrothieno[3,2-c]pyrrole
Reaction equation
[C:1]([O:4][C:5](=O)C)(=O)[CH3:2].[NH2:8][C:9]1[S:16][C:15]2[CH2:14][N:13]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[CH2:12][C:11]=2[C:10]=1[C:22]([O:24][CH2:25][CH3:26])=[O:23]>C(OC(OCC)OCC)C>[CH2:1]([O:4][CH:5]=[N:8][C:9]1[S:16][C:15]2[CH2:14][N:13]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[CH2:12][C:11]=2[C:10]=1[C:22]([O:24][CH2:25][CH3:26])=[O:23])[CH3:2]Participants
4
Procedure
0.3 ml of acetic anhydride was added to 1.4 g (4.8 mM) of 2-amino-3,5-dicarbethoxy-4,6-dihydrothieno[3,2-c]pyrrole in 14 ml of triethylorthoformate and refluxed under nitrogen for 1 h. The mixture was then completely evaporated in a rotary evaporator at 80° C. 1.6 g (99%) of crude product were isolated as a viscous oil which is sufficiently pure for further reactions.