异噁唑基取代的1,2,4-噁二唑啉和吡唑啉类化合物的合成

通过3-乙酰基-5-羟甲基异噁唑衍生的Schiff碱2与由醛肟原位生成的腈氧化物的1,3-偶极环加成反应, “一锅法”制备了5-甲基-5-5-(叔丁基二甲基硅氧基甲基)-3-异噁唑基]-3-芳基-4-(4-甲氧基苯基)-4,5二氢-1,2,4-噁二唑类化合物4a～4e; 同时由3-乙酰基-5-羟甲基异噁唑衍生的α,β-不饱和酮(5)与取代苯肼的环化反应制备了5-(叔丁基二甲基硅氧基甲基)-3-(1,5-二芳基)-3-(4,5-二氢吡唑基)]-异噁唑类化合物6a～6i. 所有新化合物的结构经核磁共振谱氢谱和碳谱、质谱、红外光谱以及高分辨质谱等进行了确证.

Synthesis of Isoxazolyl Substituted 1,2,4-Oxadiazolines and Pyrazolines

A facile method for preparation of 5-methyl-5-5-(tert-butyldimethylsiloxy-methyl)-3-isoxazolyl]-3-aryl-4-(4-methyloxyphenyl)-4,5-dihydro-1,2,4-oxadiazoles (4a～4e) via 1,3-dipolar cycloaddition of Schiff bases derived from 3-acetyl-5-hydroxymethylisoxazoles and nitrile oxides in situ generated from oximes was described. 5-(tert-Butyldimethylsiloxymethyl)-3-(1,5-diaryl-4,5-dihydropyrazol-3-yl)isoxazoles (6a～6i) were also prepared through cycloaddition of aryl hydrazine and α,β-unsaturated ketones (5) derived from 3-acetyl-5-hydroxylmethylisoxazoles. The structures of all new compounds were characterized by ¹H NMR, ¹³C NMR, MS, IR and HRMS spec-tra.