تفاعل #1999

معادلة التفاعل

benzyl alcohol

diphenylphosphoryl azide

2,2-dimethylbutanedioic acid-4-methyl ester

triethylamine

→

product

المردود 75.1%

3-Benzyloxycarbonylamino-3-methylbutanoic acid, methyl ester

المردود 75.1%

المذيبات

benzene

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةThe mixture was heated under nitrogen
2. 2
   درجة الحرارةat reflux for 45 minutes
3. 3
   درجة الحرارةrefluxing
4. 4
   درجة الحرارةThe mixture was cooled
5. 5
   ترشيحfiltered
6. 6
   تركيزthe filtrate concentrated to a minimum volume under vacuum
7. 7
   workup.DISSOLUTIONThe residue was redissolved in 250 mL of ethyl acetate
8. 8
   غسيلwashed with water, saturated aqueous sodium bicarbonate (2×) and brine
9. 9
   أخرىThe organic layer was removed
10. 10
    تجفيفdried over magnesium sulfate
11. 11
    ترشيحfiltered
12. 12
    تركيزthe filtrate concentrated to a minimum volume under vacuum
13. 13
    أخرىThe crude product was purified by medium pressure liquid chromatography on silica
14. 14
    غسيلeluting with hexane/ethyl acetate (4:1)

الإجراء التجريبي

To 14.7 g (91.8 mmol) of 2,2-dimethylbutanedioic acid-4-methyl ester in 150 mL of benzene was added 13 mL of triethylamine (9.4 g, 93 mmol) followed by 21.8 mL of diphenylphosphoryl azide (27.8 g, 101 mmol). The mixture was heated under nitrogen at reflux for 45 minutes then 19 mL (19.9 g, 184 mmol) of benzyl alcohol was added and refluxing continued for 16 hours. The mixture was cooled, filtered and the filtrate concentrated to a minimum volume under vacuum. The residue was redissolved in 250 mL of ethyl acetate, washed with water, saturated aqueous sodium bicarbonate (2×) and brine. The organic layer was removed, dried over magnesium sulfate, filtered and the filtrate concentrated to a minimum volume under vacuum. The crude product was purified by medium pressure liquid chromatography on silica, eluting with hexane/ethyl acetate (4:1), to afford 18.27 g (68.9 mmol, 75%) of the product.

المصدر