Imidazole → 2(R)-(4-methoxy-2,3,6-trimethylbenzenesulfonyl-amino)-3(S)-(triethylsilyloxy)butyric acid 3,4-methylenedioxybenzyl ester

HRID 1760820Notes

Reaction equation

[CH2:1]1[O:32][C:31]2[CH:30]=[CH:29][C:5]([CH2:6][O:7][C:8](=[O:28])[C@H:9]([NH:13][S:14]([C:17]3[C:22]([CH3:23])=[CH:21][C:20]([O:24][CH3:25])=[C:19]([CH3:26])[C:18]=3[CH3:27])(=[O:16])=[O:15])[C@@H:10]([OH:12])[CH3:11])=[CH:4][C:3]=2[O:2]1.N1C=CN=C1.[CH2:38]([Si:40](Cl)([CH2:43][CH3:44])[CH2:41][CH3:42])[CH3:39]>O1CCCC1>[CH2:1]1[O:32][C:31]2[CH:30]=[CH:29][C:5]([CH2:6][O:7][C:8](=[O:28])[C@H:9]([NH:13][S:14]([C:17]3[C:22]([CH3:23])=[CH:21][C:20]([O:24][CH3:25])=[C:19]([CH3:26])[C:18]=3[CH3:27])(=[O:16])=[O:15])[C@@H:10]([O:12][Si:40]([CH2:43][CH3:44])([CH2:41][CH3:42])[CH2:38][CH3:39])[CH3:11])=[CH:4][C:3]=2[O:2]1

Participants

Conditions

Temperature: 0 °C

Procedure

2(R)-(4-methoxy-2,3,6-trimethylbenzenesulfonylamino)-3(S)-hydroxybutyric acid 3,4-methylenedioxybenzyl ester (10.9 g, 23.41 mmol) and imidazole (2.07 g, 30.43 mmol was dissolved in tetrahydrofuran (28 mL). The reaction mixture was cooled to 0° C. and 1 M triethylsilyl chloride in tetrahydrofuran (28 mL, 28 mmol) was added. After 1 h, the reaction mixture was concentrated and chromatographed over a Biotage 40L column (eluted with 10% ethyl acetate-hexanes) to afford 2(R)-(4-methoxy-2,3,6-trimethylbenzenesulfonyl-amino)-3(S)-(triethylsilyloxy)butyric acid 3,4-methylenedioxybenzyl ester (13.5 g).

Workup

concentrationthe reaction mixture was concentrated
customchromatographed over a Biotage 40L column (eluted with 10% ethyl acetate-hexanes)

Sources & evidence

ORD record: ord-bc302498c81b4144883c5f920c902c67
Source dataset: uspto-grants-2005_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06844366B2

Reaction notes

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