Thieno[2,3-b]pyridine(8CI,9CI)

Thieno[2, 3-b] pyridine: a vigorously stirred mixture (maintained at 30 °C) of 1.08 g (8.3 mmol) of 2-nitrothiophene and 16 mL of concentrated hydrochloric acid was added, in 0.42 g batches, a total quantity of 2.08 g of granular tin. After most of the tin had dissolved, 6 mL of EtOH and 0.5 g of anhydrous ZnCl2.30 g of Thieno[2, 3-b]pyridine (17 mmol), 1.43 g Of NaHCO3 (17 mmol), 4.44 g of K2HPO4 (25.5 mmol) and 2.66 g of MgSO4 (22.1 mmol) are placed into the flask with 80 ml of dichloromethane. The reaction mixture is stirred under reflux. 1.05 ml of bromine (20.4 mmol) is added slowly to the mixture and is stirred overnight. CH2Cl2 and water are added to the cooled reaction mixture and separated. The CH2Cl2 layer is dried over Na2SO4 and evaporated. The crude product is applied onto a silica-gel chromatography column (Hexane: AcOEt=3:l) to give 1.76 g of the title compound. Yield 48%. mass spectrum (m/e):215(M+l); IH-NMR(CDCl3): 8.67(m, IH), 8.13(m, IH), 7.59(s, IH), 7.45(m, IH) ppm.Bromine (2.08 g , 13 mmol) was dropwise added to a mixture of 3-BromoThieno[2, 3-b]pyridine-2-carbaldehyde: In an atmosphere of argon a mixture of 1.3 mL (2.08 mmol) of 0.8 M n-butyllithium in hexane and 0.3 mL (3.3 mmol) of N, N, N?, N?-tetramethylethylenediamine was stirred magnetically at room temperature for 30 minutes, diluted with 5 mL of hexane, cooled in a bath of dry ice-ethanol, and treated (with vigorous stirring) dropwise (from a syringe with a small needle) with 0.23 g (1.7 mmol) of thieno[2, 3-b] pyridine. The mixture was stirred in the bath for 7 h longer and then for 12 h while it warmed to room temperature. It was cooled in ice, treated with 0.15 g (2.1 mmol) of dimethylformamide, stirred for one hour, and then treated successively with 1 mL of ethanol, 3 mL of saturated aqueous ammonium chloride solution, and 4 mL of water. The layers were separated. The organic layer (plus chloroform extracts of the aqueous layer) was dried (magnesium sulfate) and evaporated. The residue was triturated with hexane to give 0.18 g (66%) of brown solid; m.p. 131.5-132.5 C. Recrystallizations from ethanol (once with charcoal) gave white needles. 1H NMR (300 MHz, CDCl3) ppm 7.41 (dd, J = 4.5 Hz, 8.1 Hz, 1 H), 7.99 (s, 1 H), 8.24 (dd, J = 1.8 Hz, 8.1 Hz, 1 H), 8.73 (dd, J = 1.8 Hz, 4.5 Hz, 1 H), 10.12 (s, 1 H). 13C NMR (75 MHz, CDCl3) ppm 120.7, 131.8, 132.3, 134.0, 143.2, 150.5, 163.8, 185.0. IR (CHCl3, cm-1) 1682 (C=O). MS (EI, 70 eV): m/z [%] = 162[M]+ (100), 134[M-CO]+ (26). HRMS (FAB+) calculated for C8H6NOS [M+1] 164.0170, found 164.0167.

Molecular Weight:135.19
XLogP3:2.2
Hydrogen Bond Acceptor Count:2
Exact Mass:135.01427034
Monoisotopic Mass:135.01427034
Topological Polar Surface Area:41.1
Heavy Atom Count:9
Complexity:105
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes