반응 #158403

반응 방정식

sodium cyanoborohydride

tert-butyl azetidine-3-carboxylate acetic acid salt

4-cyanobenzaldehyde

→

tert-butyl 1-(4-cyanobenzyl)azetidine-3-carboxylate

수율 89.0%

용매

methanol

반응 조건

후처리

1. 1
   온도to warm to room temperature
2. 2
   농축The reaction mixture was concentrated under reduced pressure
3. 3
   workup.ADDITIONthe residue was diluted with a 10% aqueous solution of sodium bicarbonate
4. 4
   추출extracted with ethyl acetate
5. 5
   세척washed with brine
6. 6
   건조dried over anhydrous sodium sulfate
7. 7
   농축Concentration under reduced pressure
8. 8
   기타followed by purification by flash silica gel column chromatography

실험 절차

To a solution of tert-butyl azetidine-3-carboxylate acetic acid salt (92.0 g, 0.423 mol) in methanol (1.0 L) at room temperature was added 4-cyanobenzaldehyde (50.8 g, 0.381 mol). The reaction mixture was cooled to 0° C., and sodium cyanoborohydride (28.8 g, 0.458 mol) was added portion-wise. The reaction mixture was allowed to warm to room temperature and was stirred overnight. The reaction mixture was concentrated under reduced pressure, and the residue was diluted with a 10% aqueous solution of sodium bicarbonate, extracted with ethyl acetate, washed with brine, and dried over anhydrous sodium sulfate. Concentration under reduced pressure followed by purification by flash silica gel column chromatography using a 20% mixture of ethyl acetate in petroleum ether afforded tert-butyl 1-(4-cyanobenzyl)azetidine-3-carboxylate (89%) (the desired product and alcohol impurity formed were not separated by column completely, and the mixture was taken for next step). LC/MS M+1=273.18. 1H-NMR (400 MHz, CDCl3) δ ppm 1.46 (s, 9H), 3.22-3.31 (m, 3H), 3.48-3.56 (m, 2H), 3.66 (s, 2H), 7.39 (d, J=8.28 Hz, 2H), and 7.60 (d, J=8.28 Hz, 2H).

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