Ethyl chloroformate → 1-(4-tert-butyldiphenylsilyloxymethylphenyl)-4-ethoxycarbonyl-2-(1-trityl-1H-tetrazol-5-yl)pyrrole

To a stirred solution of 4-bromo-1-(4-tert-butyldiphenylsilyloxymethylphenyl)-2-(1-trityl-1H-tetrazol-5-yl)pyrrole (500 mg) in a mixture of tetrahydrofuran (5 ml) and N,N,N',N'-tetramethylethylenediamine (0.19 ml) was added n-butyl lithium (0.41 ml; 1.6M in n-hexane) at -78° C. under nitrogen atmosphere and the mixture was stirred at the same temperature for half an hour. Ethyl chloroformate (0.3 ml) was added to the mixture at the same temperature and the resulting mixture was stirred at -78° C. for half an hour, at 0° C. for one hour and then at ambient temperature for two hours. The reaction was quenched with aqueous saturated sodium bicarbonate and diluted with ethyl acetate. The organic layer was washed with brine and dried over magnesium sulfate. After filtration, the filtrate was concentrated and the residue was purified by flash chromatography eluted with a mixture of ethyl acetate-n-hexane 1:9 (V/V) to give 1-(4-tert-butyldiphenylsilyloxymethylphenyl)-4-ethoxycarbonyl-2-(1-trityl-1H-tetrazol-5-yl)pyrrole (311 mg) as a colorless viscous oil.

1. stirringthe resulting mixture was stirred at -78° C. for half an hour, at 0° C. for one hour
2. customThe reaction was quenched with aqueous saturated sodium bicarbonate
3. additiondiluted with ethyl acetate
4. washThe organic layer was washed with brine
5. dry with materialdried over magnesium sulfate
6. filtrationAfter filtration
7. concentrationthe filtrate was concentrated
8. customthe residue was purified by flash chromatography
9. washeluted with a mixture of ethyl acetate-n-hexane 1:9 (V/V)

ORDレコード

ord-a136bcd069a241aa8f82ee00232d8d31

出典データセット

uspto-grants-1993_06

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US05215994