Application of 77199-09-8, As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 77199-09-8, name is Ethyl 5-bromopicolinate, molecular formula is C8H8BrNO2, The compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below.
A suspension of 5-bromo-2-pyridinecarboxylic acid (1.0 g, 4.95 mmol) and thionyl chloride (1.4 mL, 19.8 mmol) was heated at 70 C. for 2 hours. The reaction was cooled to room temperature and the excess thionyl chloride was removed under a stream of nitrogen. Toluene (5 mL) and ethanol (2.91 mL, 49.5 mmol) were added and heated at 80 C. for 18 hours. Excess ethanol was removed under reduced pressure. Ethyl acetate was added and the mixture was neutralized with sat. NaHCO3. The organic layer was washed with water and sat. NaCl. Extract was dried over MgSO4, filtered and solvent removed under reduced pressure to give 1.07 g of ethyl 5-bromopicolinate.Ethyl 5-bromopicolinate (1.0 g, 4.35 mmol) was mixed with 4.3 mL hydrazine and 4 mL ethanol and heated at 90 C. for 70 minutes then the excess reagent and ethanol was removed with a stream of nitrogen. The wet solid was triturated with ether then 90:10 Ether:MeOH to give a gray/green solid which was dried on the vacuum pump. The yield of 5-bromopicolinohydrazide was 0.536 g.5-Bromopicolinohydrazide (0.2 g, 0.926 mmol) was mixed with 0.4 mL acetic acid and 4.0 mL phosphorus oxychloride and heated at 100 C. for 1 hour then at 120 C. for 1.5 hours. Excess reagents were removed with a stream of nitrogen. The residue was dissolved in ethyl acetate and sat. NaHCO3 was added until the mixture was slightly basic. The organic layer was washed again with sat. NaHCO3, water and finally sat. NaCl. The organic layer was dried over MgSO4, filtered and solvent was removed under reduced pressure to give 0.236 g of 2-(5-bromopyridin-2-yl)-5-methyl-1,3,4-oxadiazole.2-(5-Bromopyridin-2-yl)-5-methyl-1,3,4-oxadiazole e (0.222 g, 0.925 mmol) was mixed with 4-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (0.226 g, 0.971 mmol), palladium tetrakis triphenyl phosphine (0.012 g, 0.046 mmol), 2M K3PO4 (0.957 mL), and 3.2 mL dioxane. The reaction was purged with nitrogen, sealed in a tube and put in an oil bath at 95 C. under a balloon filled with nitrogen for 18 hours. The reaction was cooled to room temperature and filtered through a plug of Celite washing with water and ethyl acetate. The layers were separated and the water layer was extracted with ethyl acetate (2×25 mL). The combined organic layers were washed with 20 mL sat. NaCl, dried with MgSO4, filtered and solvent removed under reduced pressure. The crude product was purified by column chromatography on 100 mL Silica Gel eluting with 100% ethyl acetate followed by 90:10 ethyl acetate:MeOH to give 0.147 g of 4-methyl-3-(6-(5-methyl-1,3,4-oxadiazol-2-yl)pyridin-3-yl)aniline.Phosgene solution (0.146 mL, 0.278 mmol) in 1 mL DCM was cooled to 0 C. A solution of 4-(2-amino-5-tert-butylthiophene-3-carbonyl)-1,3,3-trimethylpiperazin-2-one (0.030 g, 0.093 mmol) in 1 mL DCM was added to the cooled phosgene solution over 5 minutes. The ice bath was removed and after 20 minutes the reaction was checked by LC/MS. The excess phosgene and solvents were removed in a stream of Nitrogen and the residue was taken up in 1 mL of DCM. 4-Methyl-3-(6-(5-methyl-1,3,4-oxadiazol-2-yl)pyridin-3-yl)aniline (0.024 g, 0.090 mmol) and DIEA (0.019 mL, 0.107 mmol) were mixed with 1 mL DCM and cooled in salt ice bath. The carbamoyl chloride solution was added dropwise to the amine solution. LC/MS of the reaction mixture 20 minutes later showed completion of the reaction. The reaction was diluted with DCM and washed with sat. NaHCO3, water and sat. NaCl. The combined organic layers were dried over MgSO4, filtered and solvent removed under reduced pressure. Purification by column chromatography on silica gel eluting with 90:10 ethyl acetate:Hex then 100% ethyl acetate gave the material contaminated with some residual aniline. This material was dissolved in DCM and two drops of Acetyl chloride were added to form the acetate of the aniline impurity. The reaction was run for 30 minutes then it was diluted with DCM and washed with sat. NaHCO3 and sat. NaCl. The organic layers were dried over MgSO4, filtered and solvent removed under reduced pressure. The solid was purified by column chromatography on silica gel eluting with 100% ethyl acetate to give 0.0168 g of 1-(5-tert-butyl-3-(2,2,4-trimethyl-3-oxopiperazine-1-carbonyl)thiophen-2-yl)-3-(4-methyl-3-(6-(5-methyl-1,3,4-oxadiazol-2-yl)pyridin-3-yl)phenyl)urea.H-1 NMR (400 MHz, CDCl3): (ppm) 10.05 (s, 1H), 8.70 (d, J=1.4 Hz, 1H), 8.24 (d, J=8.2 Hz, 1H), 7.85 (dd, J=8.2, 2.1 Hz, 1H), 7.75 (s, 1H), 7.45 (d, J=2.1 Hz, 1H), 7.30 (dd, J=8.2, 2.3 Hz, 1H), 7.21 (d, J=8.4 Hz, 1H), 6.40 (s, 1H), 3.73 (t, J=5.0 Hz, 2H), 3.46 (t, J=5.0 Hz, 2H), 3.02 (s, 3H), 2.67 (s, 3H), 2.22 (s, 3H), 1.72 (s, 6H), 1.31 (s, 9H).
While traditionally a conservative industry, chemical producers will need to modernize their PR strategies to stay relevant.we look forward to future research findings about 77199-09-8, Ethyl 5-bromopicolinate.
Reference:
Patent; LOCUS PHARMACEUTICALS, INC.; US2010/41642; (2010); A1;,
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