With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.51677-09-9,Methyl 5-phenylisoxazole-3-carboxylate,as a common compound, the synthetic route is as follows.
51677-09-9, EXAMPLES 32 TO 34General Reaction Sequence[00350] To diisopropylamine (0.04 mL, 0.314 mmol) in THF was added a solution of butyllithium (2.6 M in hexanes, 0.12 mL, 0.314 mmol) at 0 C and stirred for 30 mins. at 0 C. To the reaction mixture was added 6-methoxy-3,4-dihydronaphthalen-l(2H)-one oxime (Intermediate 2) (30 mg, 0.157 mmol) dissolved in 0.5 mL of THF at 0 C and stirred for 30 mins. The corresponding ester (0.102 mmol, 0.65 eqv.) in 0.5 mL of THF was added at 0 C and stirred at room temperature for 40 mins. To the reaction mixture was then added 0.1 mL of concentrated sulfuric acid at 0 C and stirred for 1 h at room temperature. The reaction was monitored by LCMS and when complete conversion to the product was observed, the reaction mixture was concentrated, water added (2 mL) and extracted with ethyl acetate. The ethyl acetate layer was dried over anhydrous sodium sulphate and concentrated to give the crude isoxazole derivative.[00351] To the crude isoxazole derivative was added 0.5 mL of dichloromethane followed by 3 mL of boron tribromide in dichloromethane at 0 C and stirred for 5 h at room temperature. The reaction mixture was quenched with methanol (2 mL) and concentrated. The residue was purified by Prep HPLC (XBridge, 19 x 100, 5u, 20 min. gradient; Solvent A: 10 mM NH4OAc, Solvent B: MeOH) to afford products shown in Table 1. The following esters were employed in the synthesis of final products employing this protocol.
As the paragraph descriping shows that 51677-09-9 is playing an increasingly important role.
Reference£º
Patent; BRISTOL-MYERS SQUIBB COMPANY; DHAR, T.G. Murali; XIAO, Hai-Yun; WATTERSON, Scott Hunter; KO, Soo S.; DYCKMAN, Alaric J.; LANGEVINE, Charles M.; DAS, Jagabandhu; CHERNEY, Robert J.; WO2011/59784; (2011); A1;,
Isoxazole – Wikipedia
Isoxazole | C3H3NO – PubChem