N,N,N',N'-Tetramethylethylenediamine → [5-(1,3-Dimethyl-imidazolidin-2-yl)-thiophen-2-yl]-phosphonic acid diethyl ester

Temperature

-78 °C

To a solution of 1,3-Dimethyl-2-thiophen-2-yl-imidazolidine (10 g, 60.17 mmol) in THF was added TMEDA (9.1 ml, 60.17 mmol), cooled to −78° C., then added 1.6 M nBuLi (47 ml, 75.21 mmol). After stirring at −78° C. for 30 min the mixture was warmed up to 0° C. in 1 hr and treated with diethyl chlorophosphonate (10.4 ml, 72.2 mmol). The reaction mixture was stirred at 0° C. for another 30 min. The reaction was then quenched by adding EtOAc and water. The EtOAc layer was separated and the water layer was further extracted with EOAc once. The combined EtOAc layers were dried over MgSO4, filtrated and concentrated to afford the crude product [5-(1,3-dimethyl-imidazolidin-2-yl)-thiophen-2-yl]-phosphonic acid diethyl ester (17 g). 1H NMR (300 MHz, DMSO-d6): δ 7.44 (m, 1H), 7.24 (m, 1H). 4.01 (m, 4H), 3.18 (m, 2H), 2.53 (m, 2H), 1.22 (m, 9H).

1. temperaturewas warmed up to 0° C. in 1 hr
2. stirringThe reaction mixture was stirred at 0° C. for another 30 min
3. customThe reaction was then quenched
4. additionby adding EtOAc and water
5. customThe EtOAc layer was separated
6. extractionthe water layer was further extracted with EOAc once
7. dry with materialThe combined EtOAc layers were dried over MgSO4
8. filtrationfiltrated
9. concentrationconcentrated

ORD record

ord-56414b2da4aa423e8b2382c3272918d7

Source dataset

uspto-grants-2015_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08940927B2