Iodide Ion → 7-(2,4,5-Triphenylimidazol-1-yl)heptane-phosphonic acid

HRID 1376369Notes

Reaction equation

HRID 1376369 reaction equation
[C:1]1([C:7]2[N:8]([CH2:24][CH2:25][CH2:26][CH2:27][CH2:28][CH2:29][CH2:30][P:31]([O:36]CC)(=[O:35])[O:32]CC)[C:9]([C:18]3[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=3)=[C:10]([C:12]3[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=3)[N:11]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[I-]>C(Cl)(Cl)Cl>[C:1]1([C:7]2[N:8]([CH2:24][CH2:25][CH2:26][CH2:27][CH2:28][CH2:29][CH2:30][P:31]([OH:36])(=[O:32])[OH:35])[C:9]([C:18]3[CH:19]=[CH:20][CH:21]=[CH:22][CH:23]=3)=[C:10]([C:12]3[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=3)[N:11]=2)[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

4

Reactant 2

HCID 30165Iodide IonHCID 22916421Diethyl 7-(2,4,5-triphenylimidazol-1-yl)heptane-phosphonate

Product 1

HCID 99345847-(2,4,5-Triphenylimidazol-1-yl)heptane-phosphonic acidYield 51.1%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Conditions

Temperature
-40 °C

Procedure

A mixture of 2,4,5-triphenyl-1-(7-bromoheptyl)-imidazole (0.95 g) and triethyl phosphite (1.66 g) in xylene (5 ml) was heated at reflux temperature for 20 hours. The mixture was evaporated to an oil and chromatographed on silica gel (ethyl acetate/ethanol) to give diethyl 7-(2,4,5-triphenylimidazol-1-yl)heptane-phosphonate (0.37 g, 35%) as a light brown oil. NMR μ(CDCl3) 0.9-1.7 (18H, m, 6×CH2 +2×CH3), 3.9 (2H, t, CH2N), 4.1 (4H, m, 2×CH20), 7.1-7.7 (15H, m, 3×Ph) ppm. Diethyl 7-(2,4,5-triphenylimidazol-l-yl)heptane-phosphonate (0.35 g) was dissolved in dry chloroform, cooled to -40° C and to it was added trimethylsflyl iodide (0.66 g) over 2 minutes under an atmosphere of nitrogen. The cooling bath was removed and the reaction mixture was stirred for 3 hours at room temperature then evaporated to an oil and re- evaporated from methanol and water respectively. The oil was taken up in methanol, treated with excess aqueous sodinto bicarbonate, evaporated to dryness then taken up in ethanol, filtered and the flitrate evaporated to an oil. This was taken up in water, filtered and dilute hydrochloric acid added to pH4. The precipitated oil was washed with water, taken up in methanol and precipitated with ether to give 7-(2,4,5-triphenylimidazol-1-yl)heptane-phosphonic acid (0.16 g, 51%) as a light brown oil. Found: C, 68.12; H, 6.39, N, 5.60% C28H31N2O3P+4% H2O requires: C, 68.03; H 6.76; N, 5.66%.

Workup

  1. customThe cooling bath was removed
  2. customthen evaporated to an oil
  3. customre- evaporated from methanol and water respectively
  4. additiontreated with excess aqueous sodinto bicarbonate
  5. customevaporated to dryness
  6. filtrationfiltered
  7. customthe flitrate evaporated to an oil
  8. filtrationfiltered
  9. additiondilute hydrochloric acid added to pH4
  10. washThe precipitated oil was washed with water
  11. customprecipitated with ether

Sources & evidence

ORD record
ord-c79a9531a45143f5a2a2734cc0bb8ed7
Source dataset
uspto-grants-1997_09
Patent number
US05663053

Reaction notes

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