New process for preparing 2(4-fluorophenyl) alpha methyl-5-benzoxazole acetic acid
申请人:RAVIZZA S.p.A.
公开号:EP0182061A1
公开(公告)日:1986-05-28
A process for preparing 2(4-fluorophenyl)a-methyl-5-benzoxazole acetic acid starting from 4-hydroxy-3-aminophenylacetic acid, which is firstly reacted with 4-fluorobenzoyl chloride, and the product obtained is reacted with phosphoric acid; the 2(4-fluorophenyl)5-benzoxazole acetic acid obtained in this manner is esterified with ethyl alcohol, and the ester is treated with diethyloxalate; the ethyl 2(4-fluorophenyl)5-benzoxazole oxalacetate obtained is reacted with formaldehyde and potassium carbonate to obtain ethyl 2(4-fluorophenyl)5-benzoxazole acrylate, which is hydrolysed to obtain the corresponding acid, from which the 2(4-fluorophenyl)a-methyl-5-benzoxazole acetic acid is obtained by hydrogenation.
一种以 4-羟基-3-氨基苯乙酸为起始原料制备 2(4-氟苯基)-a-甲基-5-苯并恶唑乙酸的工艺,先将 4-羟基-3-氨基苯乙酸与 4-氟苯甲酰氯反应,得到的产物再与磷酸反应,得到的 2(4-氟苯基)-5-苯并恶唑乙酸再与乙醇酯化,酯化后的产物再与草酸二乙酯处理,得到的 2(4-氟苯基)-5-苯并恶唑草酰乙酸乙酯再与甲醛和碳酸钾反应,得到 2(4-氟苯基)-5-苯并恶唑草酰乙酸乙酯;将得到的 2(4-氟苯基)-5-苯并恶唑草酰乙酸乙酯与甲醛和碳酸钾反应,得到 2(4-氟苯基)-5-苯并恶唑丙烯酸乙酯,水解得到相应的酸,再通过氢化得到 2(4-氟苯基)-a-甲基-5-苯并恶唑乙酸。