4,4'-Bis(methoxycarbonly)-2,2'-bipyridine

Dimethyl 2, 2 '-bipyridine-4, 4'-dicarboxylate (I)To a suspension of 2, 2'-dipyridyl-4, 4'-dicarboxylic acid (2.00 g, 8.10 mmol) in MeOH (150 mL) was added thionyl chloride (1492 μL, 20.48 mmol) dropwise. The mixture was stirred under reflux overnight. Then the solvent was removed under reduced pressure and the residue was partitioned between CHTake the product I obtained 2g and 10mL 98percent H2SO4, 100mL CH3OH into the flask with a stirrer, reflux at 105 ° C overnight, the end of the reaction to a large amount of water appears white flocculent precipitate, slowly adding NaOH solution adjusted to pH 9.0 , With CH2C12 extract to retain the organic phase, anhydrous Na2S04 dry, evaporated to dry the solvent to obtain white crystals, the yield of 88percent.General procedure: The 4, 4'-bis[C(0)OR]-2, 2'-bipyridine ligands (L-COOCi to L-COOC4) were synthesized as described elsewhere for the synthesis of L-COOCi (Liu et al, Polymer 52:3318-3324, 2011), with slight modifications of the procedure. Briefly, concentrated sulfuric acid (20.4 equiv) was slowly added to a suspension of 4, 4'-dicarboxylic acid-2, 2'- bipyridine (1 equiv) in the desired alcohol (~ 25 ml of alcohol per 1 g of diacid used). Once the heat subsided, the reaction mixture was refluxed for 24 hours. At the end of the reaction, the volume of the resulting bright, hot pink solution was reduced using a rotary evaporator. The crude product was precipitated out in ice water and neutralized with a 40percent NaOH solution. The pure product was obtained by recrystallization in ethanol, unless otherwise noted. L-COOCi [00215] Yield: 86percent. Mp = 210.0°C [lit. mp = 210-211°C (Case, J Am Chem Soc 68:2574-2577, 1946). Weigh 4, 4'-dicarboxy-2, 2'-bipyridine 500mg (2.05mmol) was added to the reaction flask, 100mL of methanol was added, 8mL of concentrated sulfuric acid was slowly added dropwise and stirred at 105 for 12h. After the reaction was completed and cooled to room temperature, the reaction was added to 500 mL of water, and the pH was adjusted to 9 using saturated NaOH solution. After the pH was adjusted, 200 mL of dichloromethane solution was added and allowed to stand still. At this time, a white flocculent precipitate was formed and the supernatant was poured out. The lower layer was extracted with dichloromethane and water (3 × 100 mL), the organic phase was extracted and dried to give the product , Yield 76percent.The 2, 2 '-bipyridine, methyl chloroformate, diethylamine, methanol and catalyst were mixed , then passes nitrogen gas and the reaction was carried out at 90 ° C at 3 MPa for 5 hours. In step 1), the molar ratio of 2, 2 '-bipyridine, methyl chloroformate, triethylamine is 1: 2: 5; dose ratio  of 2, 2 '-bipyridine, methanol and catalyst is 1mol: 500ml: 0.3g;the mentioned catalyst was prepared by the following method: The phosphotungstic acid and sodium tungstate were dissolved in water and added a mixture of nanometer titanium dioxide and nano zirconia which is 6 times the weight of phosphotungstic acid (this mixture contained 70percent by weight of titanium dioxide), stirred the reaction at 60 ° C for 30 h, then vacuum dried the moisture , an dried at 160 ° C for 2h; The mass ratio of the phosphotungstic acid, sodium tungstate and water is 1: 0.15: 5;after completion of the reaction, the mixture was filtered to remove insoluble matter, added to water, and extracted with ethyl acetate. After concentration, the product was obtained as a white solid 2, 2'-bipyridinyl-4, 4'-carboxylic acid methyl ester in a yield of 98.2percent.An ether solution (30 mL) of CH2N2 prepared from N-methyl-N-nitrosourea (2.18 g, 21.2 mmol) and 50percent aqueous KOH (10 mL) was added dropwise to stirred suspension of 2, 2'-bipyridine-4, 4'-dicarboxylic acid 4a (1.00 g, 4.10 mmol) in CHCl3 (80 mL) at ambient temperature. Upon the evolution of nitrogen, the reaction mixture was filtered from minor solid impurities and the solvents were removed under reduced pressure (10 Torr) at 20 S. The residue was washed with n-hexane (30 mL) and filtered off to afford 4b as light beige powder. Yield 0.94 g (85percent), mp 215 S (lit.20 mp 214 C); Rf 0.61 (Silica gel, CH2Cl2/MeOH (19:1)). The 1H NMR spectrum corresponds to reported data.

Molecular Weight:272.26
XLogP3:1.2
Hydrogen Bond Acceptor Count:6
Rotatable Bond Count:5
Exact Mass:272.07970687
Monoisotopic Mass:272.07970687
Topological Polar Surface Area:78.4
Heavy Atom Count:20
Complexity:327
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes