반응 #474384

반응 방정식

NaBH4

PCC

methylchloroformate

HCl

2,3-Dihydrobenzofuran-7-carboxylic acid

→

2,3-dihydrobenzofuran-7-carbaldehyde

수율 60.7%

용매

H2O

diethyl ether

THF

반응 조건

후처리

1. 1
   기타The white precipitates
2. 2
   기타were removed by filtration
3. 3
   workup.STIRRINGThe resulting solution was stirred overnight
4. 4
   추출extracted with EtOAc
5. 5
   세척The organic layer was washed with brine
6. 6
   건조dried over anhydrous Na2SO4
7. 7
   농축concentrated in vacuo
8. 8
   workup.DISSOLUTIONThe crude alcohol was dissolved in DCM
9. 9
   workup.STIRRINGThe mixture was stirred for 2 hours at room temperature
10. 10
    기타ether layers were decanted
11. 11
    여과Combined organic layer was filtered though a layer of Celite®
12. 12
    농축The filtrate was concentrated
13. 13
    기타to give crude product
14. 14
    기타The crude was purified from column with 10% EtOAc/hexane

실험 절차

2,3-Dihydrobenzofuran-7-carboxylic acid (820 mg, 5 mmol) was dissolved in THF (10 mL). To the solution was added TEA (0.7 mL, 5 mmol) and methylchloroformate (0.43 mL, 5 mmol). The solution was stirred for 0.5 hour. The white precipitates were removed by filtration, the filtrate was added to a solution of NaBH4 (437 mg, 12.5 mmol) in H2O (5 mL). The resulting solution was stirred overnight. The reaction mixture was neutralized with 2 M aqueous HCl solution and then extracted with EtOAc. The organic layer was washed with brine, dried over anhydrous Na2SO4 and concentrated in vacuo. The crude alcohol was dissolved in DCM. To the solution was added PCC (1.83 g, 7.5 mmol). The mixture was stirred for 2 hours at room temperature and diluted with diethyl ether, then ether layers were decanted. Combined organic layer was filtered though a layer of Celite®. The filtrate was concentrated to give crude product. The crude was purified from column with 10% EtOAc/hexane to afford 450 mg of 2,3-dihydrobenzofuran-7-carbaldehyde as a slightly yellow solid. HPLC 4.3 min.

출처