为了实现4H-噻吩[3,2-b]吡咯-5-羧酸乙酯的方便简易合成,本文采用了一种新的方法。具体而言,可以以2-噻吩甲醛和叠氮乙酸乙酯为原料,在常温条件下进行反应,合成4H-噻吩[3,2-b]吡咯-5-羧酸乙酯;或者以4H-噻唑[3,2-B]吡咯-5-甲酸为起始物料,并与乙醇反应制备得到目标产物。合成过程中的具体反应方程式如下图所示:
中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
4H-噻唑[3,2-B]吡咯-5-甲酸 | 4H-thieno[3,2-b]pyrrole-5-carboxylic acid | 39793-31-2 | C7H5NO2S | 167.188 |
中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
4H-噻唑[3,2-B]吡咯-5-甲酸 | 4H-thieno[3,2-b]pyrrole-5-carboxylic acid | 39793-31-2 | C7H5NO2S | 167.188 |
2-溴-4H-噻吩并[3,2-b]吡咯-5-羧酸乙酯 | ethyl 2-bromo-4H-thieno[3,2-b]pyrrole-5-carboxylate | 238749-50-3 | C9H8BrNO2S | 274.138 |
2-氯-4H-噻吩并[3,2-b]吡咯-5-羧酸乙酯 | ethyl 2-chloro-4H-thieno[3,2-b]pyrrole-5-carboxylate | 332099-38-4 | C9H8ClNO2S | 229.687 |
2-甲酰基-4H-噻吩并[3,2-B]吡咯-5-羧酸乙酯 | ethyl 2-formyl-4H-thieno[3,2-b]pyrrole-5-carboxylate | 59958-27-9 | C10H9NO3S | 223.252 |
4-甲基-4H-噻吩并[3,2-b]吡咯-5-羧酸乙酯 | ethyl 4-methylthieno[3,2-b]pyrrole-5-carboxylate | 106200-65-1 | C10H11NO2S | 209.269 |
—— | ethyl 6-methyl-4H-thieno[3,2-b]pyrrole-5-carboxylate | 39582-78-0 | C10H11NO2S | 209.269 |
—— | ethyl 2-nitrothieno<3,2-b>pyrrole-5-carboxylate | 91545-58-3 | C9H8N2O4S | 240.24 |
—— | 2-cyano-4H-thieno[3,2-b]pyrrole-5-carboxylic acid | 332099-48-6 | C8H4N2O2S | 192.198 |
—— | (4H-thieno[3,2-b]pyrrol-5-yl)methanol | 878657-01-3 | C7H7NOS | 153.205 |
—— | thieno[3,2-b]pyrrole-5-carbaldehyde | 1404187-18-3 | C7H5NOS | 151.189 |
—— | ethyl 4-ethylthieno[3,2-b]pyrrole-5-carboxylate | —— | C11H13NO2S | 223.296 |
4-甲基-4H-噻吩并[3,2-b]吡咯-5-羧酸 | 4-methylthieno[3,2-b]pyrrole-5-carboxylic acid | 841222-62-6 | C8H7NO2S | 181.215 |
—— | ethyl 6-formyl-4H-thieno[3,2-b]pyrrole-5-carboxylate | 94521-10-5 | C10H9NO3S | 223.252 |
—— | 2-(4-nitrophenyl)-4H-thieno[3,2-b]pyrrole-5-carboxylic acid ethyl ester | 898552-84-6 | C15H12N2O4S | 316.337 |
—— | ethyl 4-benzyl-4H-thieno[3,2-b]pyrrole-5-carboxylate | 606102-24-3 | C16H15NO2S | 285.367 |
—— | 4H-thieno[3,2-b]pyrrol-5-ylmethyl methanesulfonate | 1263413-88-2 | C8H9NO3S2 | 231.296 |
—— | 4H-thieno[3,2-b]pyrrole-5-carboxylic acid amide | 881888-43-3 | C7H6N2OS | 166.203 |
—— | ethyl 6-[(dimethylamino)methyl]-4H-thieno[3,2-b]pyrrole-5-carboxylate | 15811-13-9 | C12H16N2O2S | 252.337 |
4H-噻吩并[3,2-B]吡咯-5-甲酰肼 | 4H-thieno[3,2-b]pyrrole-5-carbohydrazide | 119448-43-0 | C7H7N3OS | 181.218 |
—— | Ethyl 4-(3,4-dichlorobenzyl)thieno[3,2-b ]pyrrole-5-carboxylate | 238748-91-9 | C16H13Cl2NO2S | 354.257 |
—— | 4-benzyl-4H-thieno[3,2-b]pyrrole-5-carboxylic acid | 837390-55-3 | C14H11NO2S | 257.313 |
—— | ethyl 6-nitrothieno<3,2-b>pyrrole-5-carboxylate | 91545-60-7 | C9H8N2O4S | 240.24 |
—— | 6-piperidin-1-ylmethyl-4H-thieno[3,2-b]pyrrole-5-carboxylic acid ethyl ester | 97375-51-4 | C15H20N2O2S | 292.402 |
—— | 4-(4-chlorobenzyl)-4H-thieno[3,2-b]pyrrole-5-carboxylic acid | 924643-46-9 | C14H10ClNO2S | 291.758 |
—— | N-phenyl-4H-thieno[3,2-b]pyrrole-5-carboxamide | —— | C13H10N2OS | 242.301 |
The 2,7-dilithiated substrates of 3,6-dimethylthieno[3,2-b]thiophene, N,N′-dimethylpyrrolo[3,2- b]pyrrole and N-methylthieno[3,2-b]pyrrole were reacted with W(CO)6 to give, after subsequent alkylation with Et3OBF4, the ditungsten biscarbene complexes [(CO)5WC(OEt)XXC(OEt)} W(CO)5] (XX = condensed heteroaromatic spacers). Sites of attack during the dilithiation of the condensed rings were studied and compared, and the yields of the desired ditungsten biscarbene complexes optimized by changing the reaction conditions according to the role of the heteroatoms in the rings. The crystallographic data of the three ditungsten biscarbene complexes are reported and their structural features compared. The methyl substituents on the condensed heteroaromatic rings play an important role in determining the molecular configurations.