2,6-Lutidine → 5-(Tert-butyl-dimethyl-silanyloxy)-3-methyl-1h-pyrrole-2-carboxylic acid methyl ester

HRID 639867Notes

Reaction equation

[Si:1]([O:8]S(C(F)(F)F)(=O)=O)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].[CH3:16][O:17][C:18]([CH:20]1[C:24]([CH3:25])=[CH:23][C:22](=O)[N:21]1C(OC(C)(C)C)=O)=[O:19].N1C(C)=CC=CC=1C>ClCCl>[CH3:16][O:17][C:18]([C:20]1[NH:21][C:22]([O:8][Si:1]([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2])=[CH:23][C:24]=1[CH3:25])=[O:19]

Participants

Conditions

Temperature: 23 °C

Procedure

tert-Butyldimethylsilyltrifluoromethanesulfonate (9.99 ml, 11.49 g, 43.5 mmol, 3.0 equiv) was added to a stirring solution of 3-methyl-5-oxo-2,5-dihydro-pyrrole-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester (3.7 g, 14.5 mmol, 1.0 equiv) and 2,6-lutidine (5.07 ml, 4.66 g, 43.5 mmol, 3.0 equiv) in dichloromethane (100 ml) at 23° C. The mixture was stirred at 23° C. for 15 h, then washed with pH=7 buffer solution (30 ml). The aqueous layer was extracted with two 40 ml portions of dichloromethane. The combined organic layers were dried over sodium sulfate. The solids were filtered and the filtrate was concentrated. The residue was purified by flash column chromatography (3% ethyl acetate-hexanes initially, grading to 6% ethyl acetate-hexanes) to afford 5-(tert-Butyl-dimethyl-silanyloxy)-3-methyl-1H-pyrrole-2-carboxylic acid methyl ester (3.46 g, 89%) as a yellow oil.

Workup

washwashed with pH=7 buffer solution (30 ml)
extractionThe aqueous layer was extracted with two 40 ml portions of dichloromethane
dry with materialThe combined organic layers were dried over sodium sulfate
filtrationThe solids were filtered
concentrationthe filtrate was concentrated
customThe residue was purified by flash column chromatography (3% ethyl acetate-hexanes initially

Sources & evidence

ORD record: ord-0fdd89974f2640a0a6d1785b7ce98db8
Source dataset: uspto-grants-2010_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07691896B2

Reaction notes

Loading…