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LIGHT YELLOW TO BEIGE CRYSTALLINE POWDER

2,6-Pyridinedimethanol can be used as a quantum dot solution for photoelectric device and biomedicine.

The preparation of 2,6-Pyridinedimethanol is as follows:2640g of 2,6-dibromomethylpyridine, 3L of 30% aqueous sodium hydroxide solution, and 10L of ethanol were placed in a 20L reaction flask. Turn on the agitation. The reaction solution was heated to reflux and the reaction was kept for 5h. The TLC to intermediate state reaction is complete. The reaction solution is cooled to room temperature, plus into 20L of ice water, stir for 20min. The aqueous phase was extracted twice with 10L of dichloromethane and the organic phases were combined. The organic phase is concentrated under reduced pressure to dry, a solid of 1232g was obtained, the yield was 88.6%, and the liquid phase was 98%.

General procedure for the synthesis of 2,6-pyridinedimethanol from dimethyl pyridine-2,6-dicarboxylate: dimethyl pyridine-2,6-dicarboxylate (9.75 g, 50 mmol) was dissolved in 40 mL of anhydrous ethanol and stirred under ice-bath conditions. Sodium borohydride (7.8 g, 4 eq.) was added in batches over 15 min and the reaction mixture was kept stirring at 0°C for 1 hr. The ice bath was then removed and the reaction mixture was allowed to continue stirring at room temperature for 2 hours. Next, the reaction mixture was placed on a steam bath and heated to reflux for 10 hours. Upon completion of the reaction, the solvent was removed by vacuum distillation. The residue was mixed with 40 mL of acetone and heated on a steam bath for 1 hour, after which the solvent was again removed by vacuum distillation. The resulting residue was mixed with 40 mL of aqueous potassium carbonate and heated on a steam bath for 1 hour, after which the solvent was removed by vacuum distillation. The final residue was dissolved in 100 mL of water and the aqueous solution was continuously extracted with chloroform for 10 h. The final 2,6-pyridinedimethanol was obtained as 6 g (87% yield). The structure of the product was confirmed by 1H NMR (400 MHz, CDCl3): δ 7.70 (t, J=7.6 Hz, 1H), 7.20 (d, J=7.7 Hz, 2H), 4.78 (s, 4H).

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