Water → Ethyl 2-(p-Toluenesulfonyloxy)acetate

HRID 2422919Notes

Reaction equation

[C:1]([O:5][CH2:6][CH3:7])(=[O:4])[CH2:2][OH:3].[S:8](Cl)([C:11]1[CH:17]=[CH:16][C:14]([CH3:15])=[CH:13][CH:12]=1)(=[O:10])=[O:9].C(N(CC)CC)C.O>C(OCC)C>[S:8]([O:3][CH2:2][C:1]([O:5][CH2:6][CH3:7])=[O:4])([C:11]1[CH:17]=[CH:16][C:14]([CH3:15])=[CH:13][CH:12]=1)(=[O:10])=[O:9]

Participants

Conditions

Temperature: 0 °C

Procedure

A solution of ethyl glycolate (500 mg, 4.8 mmol) and tosyl chloride (915 mg, 4.8 mmol) in anhydrous diethyl ether (2 ml) at 0° C. was treated dropwise with triethylamine (1.34 ml, 9.6 mmol). The temperature was maintained at 0° C. with stirring for a further 2 h. After this time, water was added and the phases separated. The aqueous phase was extracted with fresh diethyl ether. The combined organic extracts were dried (MgSO4), filtered and the solvent removed in vacuo. The crude product was purified by column chromatography over silica gel (Rf=0.29, 25% ethyl acetate in hexane) affording the tosylate 2 as a colorless oil which solidified on standing as a white solid (868 mg, 70%). [This procedure was repeated on 2× scale (1.8 g, 73%)]. δH (400 MHz, CDCl3) 1.22-1.27 (3H, m, CH3), 2.46 (3H, s, ArCH3), 4.16-4.22 (2H, m, CH2CH3), 4.58-4.59 (2H, m, OCH2), 7.36 (2H, d, J=8.2 Hz, ArH), 7.84 (2H, d, J=8.2 Hz, ArH); δc (100.6 MHz, CDCl3) 14.2, 21.9, 62.1, 64.9, 128.3, 130.1, 132.9, 145.5, 166.2; MS (ES+) 276.0 (100%, [M+H2O]+) (ion not detected in ES−).

Workup

customthe phases separated
extractionThe aqueous phase was extracted with fresh diethyl ether
dry with materialThe combined organic extracts were dried (MgSO4)
filtrationfiltered
customthe solvent removed in vacuo
customThe crude product was purified by column chromatography over silica gel (Rf=0.29, 25% ethyl acetate in hexane)

Sources & evidence

ORD record: ord-5ee91aa14e5242ac8a330889c394c978
Source dataset: uspto-grants-2011_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07960434B2

Reaction notes

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