With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.13391-28-1,5-Methoxybenzofuran,as a common compound, the synthetic route is as follows.
Step A: Preparation of 5-Methoxy-2-sulfamoylbenzo[b]furan A solution of 5-methoxybenzo[b]furan (10.8 g, 73 mmol) in 100 ml of dry THF was cooled to -65 C. A 1.6M solution of n-butyllithium in hexane (50 ml, 80 mmol) was added rapidly, dropwise, such that the temperature did not exceed -55 C. After 15 minutes at -55 C. sulfur dioxide gas was passed into the reaction flask until an aliquot removed from the flask and dissolved in water was no longer basic to pH paper. Hexane (100 ml) was added to precipitate the product. After warming to room temperature, the product was isolated by filtration. The crude product was dried under low vacuum for 18 hours at room temperature, yielding 15.6 g (98%) of a tan powder. The dry sulfinate salt so obtained was suspended in 150 ml CH2 Cl2 and cooled to 5 C. prior to adding 10.7 g of N-chlorosuccinimide (80 mmol). Stirring was continued for 15 minutes at 5 C. and the cooling bath was removed. After an additional 15 minutes the suspension was filtered through a pad of filter aid. Evaporation of the solvent furnished 17.2 g of sulfonyl chloride as a brown solid. This material was dissolved in 50 ml of dry acetone and added over a 1 minute period to a chilled (5 C.) stirring solution of 15 ml NH4 OH in 150 ml acetone. After 30 minutes the solvent was evaporated. The residue was partitioned between water and ethyl acetate. The organic phase was washed with brine and dried (Na2 SO4). Evaporation left 17.2 g of brown solid. The pure compound was obtained by recrystallization from dichloroethane; m.p. 119-120 C. Analysis calculated for C9 H9 NO4 S: C, 47.57; N, 6.16; H, 3.99; Found: C, 47.52; N, 6.14; H, 4.02. ‘H NMR (d6 -acetone) 7:7.50 (1H, d, J=9), 7.30 (1H, s), 7.25 (1H, d, J=3), 7.1 (1H, dd, J=9, 3), 3.83 (3H, s).
As the paragraph descriping shows that 13391-28-1 is playing an increasingly important role.
Reference£º
Patent; Merck & Co., Inc.; US4544667; (1985); A;,
Benzofuran – Wikipedia
Benzofuran | C8H6O – PubChem