Reference of 98353-08-3, Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps,and cheap raw materials. 98353-08-3, name is 5-Ethoxypicolinic acid. A new synthetic method of this compound is introduced below.
5-Ethoxypicolinic acid (53.6 mg, 320 muiotaetaomicron) was suspended in dichloromethane (5 mL), the suspension was cooled to 0-5C (ice bath) and oxalyl chloride (56.9 mg, 39.3 mu, 448 muiotaetaomicron) as well as dimethylformamide (0.308 M in toluene, 51.9 mu, 16 muiotaetaomicron) were added. The mixture was stirred for 2.5 h at room temperature. Then, it was concentrated in vacuo (40C, 5 mbar) and dried azeotropically by two cycles of addition of toluene (3 mL) followed by concentration in vacuo to afford 5-ethoxypicolinoyl chloride as purple oil (59 mg, quant.). After that, tert-butyl ((3aS,4R,8R)-4-(5-amino-2-fluorophenyl)-4,7,7-trimethyl-8-oxido-3,3a,4,7-tetrahydro-2H- isothiazolo[l,5-a][l,4]thiazin-6-yl)carbamate (Int-16ABp, 80 mg, 188 muiotaetaomicron) was dissolved in dichloromethane (5 mL), the solution cooled to 10C and N,N-diisopropylethylamine (36.5 mg, 49.4 mu, 283 muiotaetaomicron) was added, followed by a solution of 5-ethoxypicolinoyl chloride (vide supra, 47.5 mg, 256 muiotaetaomicron) in dichloromethane (4 mL). The reaction mixture was stirred for 15 min at 10C. Then, methanol (2 mL) was added, the mixture was stirred for 5 min at room temperature and concentrated in vacuo. The crude was purified by column chromatography (silica gel, 24 g, eluting with 2 M ammonia in methanol / dichloromethane, gradient 1:99 to 3:97) to yield, after drying in vacuo (40C, 5 mbar), the title compound as a colorless viscous oil (95 mg, 88% yield). HPLC (method LCMS_fglm) tR = 1.36 min. MS (ES+) m/z 574.4 [M+H].
At the same time, in my other blogs, there are other synthetic methods of this type of compound,98353-08-3, 5-Ethoxypicolinic acid, and friends who are interested can also refer to it.
Reference:
Patent; F. HOFFMANN-LA ROCHE AG; HOFFMANN-LA ROCHE INC.; BARTELS, Bjoern; DOLENTE, Cosimo; GUBA, Wolfgang; HAAP, Wolfgang; OBST SANDER, Ulrike; VIFIAN, Walter; WOLTERING, Thomas; (89 pag.)WO2017/25491; (2017); A1;,
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem