Preparation background and overview of 2,2′-bipyridyl-6,6′-dicarboxaldehyde
2,2′-Bipyridyl-6,6′-dicarboxaldehyde is an organic intermediate that can be prepared by substitution of 6,6′-dibromo-2,2′-bipyridine or by 6,6′ -Bis-(hydroxymethyl)-2,2′-bipyridine is obtained by oxidation.
Preparation of 2,2′-bipyridyl-6,6′-dicarboxaldehyde
Preparation report of 2,2′-bipyridyl-6,6′-dicarboxaldehyde 1.
A warm solution (ca. 50°C) of 6,6′-dibromo-2,2′-bipyridine (1.0 g, 3.18 mmol) in THF (50 mL) was slowly added to 2.5Mn-BuLi (3.84 mL, 9.6 mmol, 3.0 equiv) in THF (60 mL) at -78°C, add slowly so that the temperature does not rise above -70°C and to avoid precipitation. The resulting dark red solution was stirred below -75 °C for 45 min and then quenched with DMF (0.74 mL, 9.6 mmol, 3.0 equiv). The solution was allowed to warm to -30 °C and aqueous HCl (4M, 20 mL) was added. The reaction mixture was then allowed to reach room temperature. Separate the aqueous layer from the organic phase. The aqueous layer was basified to pH 14 with saturated KOH solution. And wash with warm (about 40°C) CHCl3 (2×30mL). The combined organic extracts were washed with brine (2 x 100 mL), dried over MgSO and concentrated in vacuo. The obtained solid was slurried with MeOH (20 mL), the product was collected by filtration, and recrystallized from toluene to obtain 2 subbismuth carbonate, 2′-bipyridyl-6,6′-dicarboxaldehyde, solid, yield 0.41g, 70%.
Preparation Report 2 of 2,2′-bipyridyl-6,6′-dicarboxaldehyde
Dissolve oxalyl chloride (452 mg, 0.30 mL, 3.56 mmol, 2.2 equiv) in CH2Cl under N2 and -60°C. 2 (20 mL), a solution of dry DMSO (556 mg, 7.12 mmol, 4.4 equivalents) was dissolved in anhydrous CH2Cl2 (5 mL) . The mixture was stirred at this temperature for 5 min, then 6,6′-bis-(hydroxymethyl)-2,2′-bipyridine (8) (350 mg, 1.62 mmol, 1.0 equiv) in CH2 A solution of Cl2 (50mL, add the minimum amount of dry DMSO dropwise to dissolve all substances) was slowly added dropwise to the above system. After 15 minutes, dry NEt3 (16.2 mmol, 1.63 g, 2.26 mL, 10 equiv) was added and the mixture was allowed to reach room temperature over the course of approximately 200°C. Water (75 mL) was added at 5 hours, the phases were separated, and the aqueous layer was extracted with CH2Cl2 (2 × 50 mL). After drying the combined organic phases (MgSO4), the solvent was removed under reduced pressure and the remaining light brown solid was subjected to column chromatography (SiO2, CH2Cl2/MeOH, 24:1, detection: UV). The solid product was isolated as a colorless solid, yield 196 mg, 57%. 1HNMR (200MHz, CDCl3): δ10.19 (s, 2H), 8.85-8.81 (m, 2H), 8.078.02 (m, 4H) ppm .
References
[1]GennadiyIlyashenko, Rahela Choudhury, Majid Motevalli, et al.Concentration-DependentChemoandRegioselectiveMetalationof6,6′-Dibromo-2,2′-bipyridine[J]. Synlett, 2006, 2006(11):1759-176 Lithium tetrafluoroborate 1 .
[2]DependenceofthePhotophysicalPropertiesontheNumberof2,2′-BipyridineUnitsinaSeriesofLuminescentEuropiumandTerbiumCryptates,ByAlzakhem,Nicolaetal,FromInorganicChemistry,51(17),9343-9349;2012
