تفاعل #413862

معادلة التفاعل

4-(acetyloxy)-2,2,6,6-tetramethyl 3,5-heptanedione

ammonium acetate

→

1-[4-(1,1-dimethylethyl)-2-methyl-5-oxazolyl]-2,2-dimethyl-1-propanone

المردود 92.5%

المذيبات

acetic acid

water

sodium hydroxide

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةThe reaction mixture is heated
2. 2
   درجة الحرارةat reflux overnight
3. 3
   استخلاصThe product is extracted into ethyl acetate (3×150 mL)
4. 4
   غسيلthe combined organic layers are washed with 0.1N NaOH, water
5. 5
   أخرىThe organic layer is dried
6. 6
   أخرىevaporated
7. 7
   غسيلThe silica pad is eluted with hexane (100 mL)
8. 8
   غسيلThen the product is eluted from the silica with hexane/ethyl acetate (4:1)

الإجراء التجريبي

A solution of 4-(acetyloxy)-2,2,6,6-tetramethyl 3,5-heptanedione (22 g, 0.09 mol) in acetic acid (100 mL) is treated with ammonium acetate (44 g). The reaction mixture is heated at reflux overnight. The reaction mixture is diluted with water and neutralized (to pH 5) by the addition of aqueous sodium hydroxide. The product is extracted into ethyl acetate (3×150 mL) and the combined organic layers are washed with 0.1N NaOH, water, and then brine. The organic layer is dried and evaporated. The residue is taken up in hexane (50 mL) and applied to a pad of silica gel (500 g). The silica pad is eluted with hexane (100 mL). Then the product is eluted from the silica with hexane/ethyl acetate (4:1) to give 18.6 g (91%) of 1-[4-(1,1-dimethylethyl)-2-methyl-5-oxazolyl]-2,2-dimethyl-1-propanone as an oil.

المصدر