반응 #942052

반응 방정식

Ethyl azodicarboxylate

PPh3

Methyl 7-hydroxy-8-methyl-2-(trifluoromethyl)-2H-chromene-3-carboxylate

methyl 7-hydroxy-8-methyl-2-(trifluoromethvl)-2H-chromene-3-carboxylate

2-ethyl butanol

→

methyl 7-(2-ethylbutoxy)-8-methyl-2-(trifluoromethyl)-2H-chromene-3-carboxylate

용매

THF

반응 조건

후처리

1. 1
   workup.STIRRINGthe mixture was stirred at room temperature overnight
2. 2
   여과The polymer was filtered off through celite pad
3. 3
   세척the pad was washed with ether
4. 4
   농축The filtrate was concentrated
5. 5
   기타The undissolved solid was removed by filtration
6. 6
   기타the filtrate was evaporated
7. 7
   기타dried in vacuo
8. 8
   기타to afford yellow solid, (1.76 g, 98%)
9. 9
   기타to use without further purification

실험 절차

Polymer bound PPh3 was suspended in THF for 15 min. Methyl 7-hydroxy-8-methyl-2-(trifluoromethyl)-2H-chromene-3-carboxylate from Step 1 (1.5 g, 5.21 mmole) and 2-ethyl butanol (0.96 mL, 7.81 mmole) were added to the above slurry and stirred for 15 min. Ethyl azodicarboxylate (1.23 mL, 7.81 mmole) was added to above mixture dropwise and the mixture was stirred at room temperature overnight. LCMS indicated product formation and that there was no 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 undissolved solid was removed by filtration and the filtrate was evaporated and dried in vacuo to afford yellow solid, (1.76 g, 98%): LCMS m/z395.15 (M+Na). 1H NMR (CDCl3/400 MHz) 7.68 (s, 1H), 7.00 (d, 1H, J=8.4 Hz), 6.48 (d, 1H, J=8.4 Hz), 5.68 (q, 1H, J=7.2 Hz), 3.89 (m, 2H), 3.82 (s, 3H), 2.09 (s, 3H), 1.72 (m, 1H), 1.53 (m, 4H), 0.95 (m, 6H). This ester was of suitable purity to use without further purification.

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