反応 #942042

反応方程式

Ethyl azodicarboxylate

PPh3

Ethyl 7-hydroxy-2-(trifluoromethyl)-2H-chromene-3-carboxylate

ethyl 7-hydroxy-2-(trifluoromethyl)-2H-chromene-3-carboxylate

2-ethyl-1-butanol

→

ethyl 7-(2-ethylbutoxy)-2-(trifluoromethyl)-2H-chromene-3-carboxylate

溶媒

THF

反応条件

後処理

1. 1
   workup.STIRRINGthe mixture was stirred at room temperature overnight
2. 2
   ろ過The polymer was filtered off through celite pad
3. 3
   洗浄the pad was washed with ether
4. 4
   濃縮The filtrate was concentrated
5. 5
   ろ過The suspension was filtered
6. 6
   その他the filtrate was evaporated
7. 7
   その他dried in vacuo
8. 8
   その他to afford yellow oil, (2.37 g, 92%)
9. 9
   その他to use without further purification

実験手順

The polymer bound PPh3 was suspended in THF for 15 min. Ethyl 7-hydroxy-2-(trifluoromethyl)-2H-chromene-3-carboxylate from Example 1a, Step 1 (2.0 g, 6.94 mmole) and 2-ethyl-1-butanol (1.3 mL, 10.35 mmole) were added to above slurry and the mixture was stirred at r.t. for 15 min. Ethyl azodicarboxylate (1.6 mL, 10.35 mmole) was added to above mixture dropwise and the mixture was stirred at room temperature overnight. LCMS indicated product formation and that there was a trace amount of starting material present. The polymer was filtered off through celite pad and the pad was washed with ether. The filtrate was concentrated and the product mixture was suspended in hexane. The suspension was filtered and the filtrate was evaporated and dried in vacuo to afford yellow oil, (2.37 g, 92%): LCMS m/z 394.95 (M+Na). This ester was of suitable purity to use without further purification.

出典