반응 #1426

반응 방정식

benzylchloroformate

pyridine

3-pyrazolidinecarboxylic acid, 1,1-dimethylethyl ester

→

title product

1-[(Phenylmethoxy)carbonyl]-3-pyrazolidine-carboxylic acid, 1,1-dimethylethyl ester

용매

acetonitrile

ethyl acetate

acetonitrile

반응 조건

후처리

1. 1
   기타evaporated to dryness
2. 2
   기타the syrup obtained
3. 3
   세척The solution was washed with 5% sodium bicarbonate (2×25 ml.) and brine (25 ml.)
4. 4
   건조dried (anhydrous sodium sulfate)
5. 5
   여과filtered
6. 6
   기타evaporated to dryness
7. 7
   기타dried in vacuo
8. 8
   기타The crude product mixture was chromatographed on a silica gel column (Merck)
9. 9
   세척eluting the column with ethyl acetate
10. 10
    기타hexane mixtures (1:4; 1:2) to give 11.144 g

실험 절차

A solution of 3-pyrazolidinecarboxylic acid, 1,1-dimethylethyl ester (10.935 g., 63.5 mmol.) in dry acetonitrile (90 ml.) was cooled to 0° C. (ice-salt bath) and treated with dry pyridine (11.0 ml.) followed by a solution of benzylchloroformate (12.54 g., 10.5 ml., 69.9 mmol.) in dry acetonitrile (25 ml.). The reaction was stirred at 0° C. for 3 hours, evaporated to dryness and the syrup obtained was redissolved in ethyl acetate (250 ml.). The solution was washed with 5% sodium bicarbonate (2×25 ml.) and brine (25 ml.), dried (anhydrous sodium sulfate), filtered, evaporated to dryness and dried in vacuo. The crude product mixture was chromatographed on a silica gel column (Merck), eluting the column with ethyl acetate:hexane mixtures (1:4; 1:2) to give 11.144 g. of title product as a syrup.

출처