3,4-Dimethoxythiophene

Production Method:

Under argon protection, 21 g of sodium methoxide and 72 g of methanol were added to a 100 mL four-necked flask (the initial concentration of sodium methoxide in methanol was 22.6 wt%), and stirred until completely dissolved. Then, 0.83 g of cuprous bromide was added as a catalyst, and 15 g of 3,4-dibromothiophene was slowly added dropwise. The reaction solution gradually changed from colorless to black and transparent. After the addition was complete, 50 g of methanol was removed by distillation (at this point, the concentration of sodium methoxide in the remaining methanol increased to 48.8 wt%). The reaction mixture was heated to 97 °C and refluxed. Gas chromatography monitoring showed that after 5 hours of reaction, the contents of 3,4-dibromothiophene and 3-bromo-4-methoxythiophene were both below the detection limit. After the reaction was complete, water was added to the mixture, and after filtration, the crude product was extracted with toluene. The toluene layer was washed with water and dried over magnesium sulfate. After filtering to remove the desiccant, the toluene layer was concentrated by rotary evaporation, followed by vacuum distillation to obtain 7.28 g of 3,4-Dimethoxythiophene, with a yield of 81.5%. Gas chromatography (Agilent 6890N network GC, FID detector) showed a product purity of 98.01%.

Applications:
To synthesize the structural unit of the N2S2-N4 porphyrin dimer, which will be used to study photoinduced energy transfer.