반응 #685019

반응 방정식

benzyl 3-oxopyrrolidine-1-carboxylate

ethylene glycol

→

desired product

수율 101.4%

Benzyl 1,4-dioxa-7-azaspiro[4.4]nonane-7-carboxylate

수율 101.4%

용매

EtOAc

benzene

반응 조건

후처리

1. 1
   온도at reflux
2. 2
   온도the reaction mixture was cooled
3. 3
   세척washed with water (2×25 mL), brine (25 mL)
4. 4
   건조dried (MgSO4)
5. 5
   여과filtered
6. 6
   농축concentrated
7. 7
   기타to give yellow oil
8. 8
   기타Flash column chromatography purification on silica gel column with 1:4

실험 절차

A solution of benzyl 3-oxopyrrolidine-1-carboxylate (11.2 g, 51.09 mmol), ethylene glycol (2.4 g, 38.67 mmol) and TsOH.H2O (10 mg) in benzene (100 mL) was heated at reflux using Dean-Stork condenser. After 20 h, the reaction mixture was cooled, diluted with EtOAc (100 mL), washed with water (2×25 mL), brine (25 mL), dried (MgSO4), filtered and concentrated to give yellow oil. Flash column chromatography purification on silica gel column with 1:4 followed by 3:7 EtOAc:hexanes provided desired product (10.32 g, 100%) as colorless liquid. 1H NMR (500 MHz, CDCl3) δ: 7.38-7.28 (5H, m), 5.13 (2H, s), 3.99-3.92 (4H, m), 3.58-3.54 (2H, m), 3.45 (2H, d, J=10.7 Hz), 2.07-2.02 (2H, m).

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