3-(3,4-亚甲基二氧苯基)-5-苯基异噁唑啉的合成

以3,4-亚甲基二氧苯甲醛为起始原料,经缩合、氯化和1,3-偶极环加成三步反应合成3-(3,4-亚甲基二氧苯基)-5-苯基异噁唑啉(3),其中第一、二步反应分别得到相应的肟(1)和氯代肟(2),第三步经氯代肟与三乙胺反应生成的腈氧化合物再与苯乙烯发生1,3-偶极环加成生成异噁唑啉。研究了三乙胺的用量和反应温度对反应的影响,在较好条件下,以氯代肟为基准,第三步1,3-偶极环加成得3-(3,4-亚甲基二氧苯基)-5-苯基异噁唑啉(3)的收率为92%。

Synthesis of 3-(3,4-Methylenedioxyphenyl)-5-Phenyl-2-Isoxazoline

In order to synthesize 3-(3,4-methylenedioxyphenyl)-5-phenyl-2-isoxazoline (3), a three-step synthetic procedure was developed, which involved condensation, chlorination and 1,3-dipolar cycloaddition. In the first two steps, the oxime (1) and hydroximoyl chloride (2) were synthesized from heliotropin. In the presence of triethylamine (Et₃N), a series of hydroximoyl chloride was transformed into nitrile oxide, followed by reacting with styrene via 1,3-dipolar cycloaddition to afford (3). Dosage of Et₃N and temperature of reaction were optimized. Under the optimized conditions, the yield of (3) is 92%.