Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl ester → 4-tert-butoxycarbonylamino-3-(tert-butoxycarbonylamino-methyl)-but-2-enoic Acid Ethyl Ester

HRID 1624353Notes

Reaction equation

[C:1]([O:5][C:6](=[O:20])[NH:7][CH2:8][C:9](=O)[CH2:10][NH:11][C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])([CH3:4])([CH3:3])[CH3:2].[C:21]([CH:26]=P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)([O:23][CH2:24][CH3:25])=[O:22]>C1C=CC=CC=1>[CH2:24]([O:23][C:21](=[O:22])[CH:26]=[C:9]([CH2:10][NH:11][C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH2:8][NH:7][C:6]([O:5][C:1]([CH3:4])([CH3:3])[CH3:2])=[O:20])[CH3:25]

Participants

Conditions

Temperature: 45 °C

Procedure

To a solution of (3-tert-Butoxycarbonylamino-2-oxo-propyl)-carbamic acid tert-butyl ester (28 g, 97.0 mmol) dissolved in benzene (350 ml) was added (carbethoxymethylene)-triphenyl phosphorane (89 g, 0.26 mol) and the reaction mixture stirred for 16 hours at 45° C., under a N2 atmosphere. The mixture was concentrated and purified by column chromatography on silica gel (ethyl acetate:hexane, 1:3, v/v) to afford the product as a yellowish solid (26 g, 75%). 1H NMR (CDCl3) δ 1.43 (s, 18H), 1.59 (s, 3H), 3.90 (d, 2H, J=4.75 Hz), 4.11 (m, 4H), 5.35 (m, 2H), 5.87 (s, 1H).

Workup

concentrationThe mixture was concentrated
custompurified by column chromatography on silica gel (ethyl acetate

Sources & evidence

ORD record: ord-93ea63e7407d451da53a306af58cea99
Source dataset: uspto-grants-2014_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08778967B2

Reaction notes

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