Bromotrimethylsilane → [2-[2-(2-Methoxyethoxy)ethoxy]ethyl]phosphonic acid

Temperature

-35 °C

{2-[2-(2-Methoxyethoxy)ethoxy]ethyl}phosphonic acid diethyl ester (1.00 g, 3.5 mmol) was dissolved in CH2Cl2 (20 ml) under N2. Bromotrimethylsilane (2.3 ml, 17.5 mmol) was added via syringe and the mixture was stirred for 2 hours. Volatiles were removed in vacuo to give a thick orange oil; this was dissolved in MeOH (100 ml) with fuming to give a give a yellow solution. The mixture was stirred for 2 hours and evaporated to dryness to give a thick yellow oil which was dissolved in CH2Cl2 and extracted with NaOH (3×50 ml, aq., 1M). HCl (conc.) was added to the yellow aqueous layer until the solution was acidic to pH paper. Removal of water in vacuo gave a yellow crystalline solid that was extracted with EtOH and filtered. Cooling the filtrate to −35° C. resulted in precipitation of further white solid which was removed by filtration. Removal of volatiles from the yellow supernatant under vacuum (0.01 torr) afforded the desired product as a thick yellow oil. Yield 0.60 g, 2.6 mmol, 74%. 1H NMR (d6-DMSO, 400 MHz, 298 K): δ 3.55 (ap. q. J=7 Hz, 2H), 3.48 (m, 6H), 3.41 (m, 2H), 3.23 (s, 3H), 1.83 (d of t, JH-P=19 Hz, JH-H=7 Hz, 2H). 13C{1H} NMR (d6-DMSO, 100 MHz, 298 K): δ 71.25, 69.69, 69.58, 69.27, 65.41, 58.05, 28.99 (d, JC-P=132 Hz). 31P{1H} NMR (d6-DMSO, 162 MHz, 298 K): δ 23.15. MS (ESI, m/z): 227 (44−, 100%), 229 ([M+H]+, 10%). Exact mass found (calculated for [M+H]+, m/z): 229.08490 (229.08410).

1. customVolatiles were removed in vacuo
2. customto give a thick orange oil
3. customto give
4. customa give a yellow solution
5. stirringThe mixture was stirred for 2 hours
6. customevaporated to dryness
7. customto give a thick yellow oil which
8. extractionextracted with NaOH (3×50 ml, aq., 1M)
9. additionHCl (conc.) was added to the yellow aqueous layer until the solution
10. customRemoval of water in vacuo
11. customgave a yellow crystalline solid
12. extractionthat was extracted with EtOH
13. filtrationfiltered
14. customresulted in precipitation of further white solid which
15. customwas removed by filtration
16. customRemoval of volatiles from the yellow supernatant under vacuum (0.01 torr)

ORD record

ord-5001339a66b742199890cf9800d7d3c3

Source dataset

uspto-grants-2013_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08405069B2