반응 #42194

반응 방정식

(±)-1-(3,6,7,8-tetrahydro-2H-indeno[4,5-b]furan-2-yl)methanamine

diisopropylethylamine

benzyl chloroformate

→

(±)-benzyl 3,6,7,8-tetrahydro-2H-indeno[4,5-b]furan-2-ylmethylcarbamate

수율 68.3%

용매

tetrahydrofuran

반응 조건

후처리

1. 1
   기타The reaction mixture was quenched by the addition of saturated aqueous ammonium chloride (100 mL)
2. 2
   추출extracted with diethyl ether (2×150 mL)
3. 3
   세척The combined organic extracts were washed with saturated aqueous sodium chloride (100 mL)
4. 4
   건조dried (magnesium sulfate)
5. 5
   기타the solvent was removed in vacuo
6. 6
   기타to provide a crude oil
7. 7
   기타Purification by flash column chromatography (silica, ethyl acetate:hexanes 1:9)

실험 절차

To a solution of (±)-1-(3,6,7,8-tetrahydro-2H-indeno[4,5-b]furan-2-yl)methanamine (0.568 g, 3.00 mmol) in tetrahydrofuran (30 mL) cooled to 0° C. was added diisopropylethylamine (0.427 g, 3.30 mmol) followed by benzyl chloroformate (0.538 g, 3.15 mmol) and the reaction mixture was allowed to stir at 0° C. for 1 h. The reaction mixture was quenched by the addition of saturated aqueous ammonium chloride (100 mL) and extracted with diethyl ether (2×150 mL). The combined organic extracts were washed with saturated aqueous sodium chloride (100 mL), dried (magnesium sulfate), and the solvent was removed in vacuo to provide a crude oil. Purification by flash column chromatography (silica, ethyl acetate:hexanes 1:9) afforded 0.663 g (68%) of (±)-benzyl 3,6,7,8-tetrahydro-2H-indeno[4,5-b]furan-2-ylmethylcarbamate as a white solid. Rf=0.30 (silica, ethyl acetate:hexanes 1:9); mp 99-101° C.; Anal. calcd. for C20H21NO3: C, 74.28; H, 6.55; N, 4.33. Found: C, 73.82; H, 6.53; N, 4.25. Chiral HPLC separation of (±)-benzyl 3,6,7,8-tetrahydro-2H-indeno[4,5-b]furan-2-ylmethylcarbamate (Chiralcel OJ, isopropanol:hexane 7:3) provided two fractions. Fraction 1 (Rt=13.237 min, Chiralcel OJ, isopropanol:hexanes 3:7); Fraction 2 (Rt=16.526 min, Chiralcel OJ, isopropanol:hexanes 3:7).

출처