Iodine → HCID 14906787, compound

Temperature

-78 °C

db) 52.5 g (0.170 mol) of (m-metho xyphenyl)-diphenylphosphine oxide were placed in a 1.5 l four-necked sulphonation flask as described under da) and the apparatus was placed under argon by 3-fold evacuation/filling. Then, 350 ml of dry tetrahydrofuran were allowed to flow in and the solution was cooled to -78° C. 313 ml (0.186 mol) of the lithium diisopropylamide solution prepared under da) were added dropwise within 20 minutes while stirring well, with the temperature being held at ≤-70° C. The reaction mixture became reddish-brown in colour at the beginning of the addition and formed a beige suspension towards the end of the addition. After an additional period of stirring of 15 minutes at -78° C. a solution of 47.4 g of iodine in 170 ml of tetrahydrofuran was added dropwise to the solution within 20 minutes, with the reaction mixture being held at ≤-70° C. (The iodine solution had been prepared previously in a separate 250 ml Schlenk tube under argon and had been transferred into the dropping funnel via a steel cannula). Towards the end of the addition there resulted a red solution and there set in the formation of a reddish-brown viscous material which settled on the walls and on the bottom of the reaction vessel. At this point the mechanical stirrer was shut off, the cooling bath was removed and the reaction mixture was left to warm. At about -30° C. there again resulted a clear red solution, the stirring operation was resumed and the mixture was allowed to warm to 0° C. The reaction solution was treated at 0° C. with a solution of 12 g of sodium thiosulphate pentahydrate in 100 ml of deionized water, the mixture was stirred well and the phases were separated. The now yellowish organic phase was washed three times with 200 ml of saturated NaCl solution, dried over about 50 g of magnesium sulphate, filtered and concentrated to dryness on a rotary. evaporator at 40° C. The brown residue was treated with 300 ml of tert.-butyl methyl ether and the mixture was boiled at reflux, whereby the product began to crystallize out. After standing overnight at room temperature the beige crystallizate was filtered off under suction, washed with 100 ml of tert.-butyl methyl ether and dried for 1 hour in a high vacuum at 70° C. There were obtained 55.7 g of (2-iodo-3-metho xyphenyl)diphenylphosphine oxide as a beige powder of m.p. 186°-189° C.

1. additionwere added dropwise within 20 minutes
2. custombeing held at ≤-70° C
3. additionThe reaction mixture became reddish-brown in colour at the beginning of the addition
4. customformed a beige suspension
5. additiontowards the end of the addition
6. additionwas added dropwise to the solution within 20 minutes, with the reaction mixture
7. custombeing held at ≤-70° C.
8. customhad been prepared previously in a separate 250 ml Schlenk tube under argon
9. additionTowards the end of the addition
10. customthere resulted a red solution
11. customthe cooling bath was removed
12. waitthe reaction mixture was left
13. temperatureto warm
14. customAt about -30° C. there again resulted a clear red solution
15. temperatureto warm to 0° C
16. stirringthe mixture was stirred well
17. customthe phases were separated
18. washThe now yellowish organic phase was washed three times with 200 ml of saturated NaCl solution
19. dry with materialdried over about 50 g of magnesium sulphate
20. filtrationfiltered
21. concentrationconcentrated to dryness on a rotary
22. customevaporator at 40° C
23. additionThe brown residue was treated with 300 ml of tert.-butyl methyl ether
24. temperatureat reflux
25. customto crystallize out
26. filtrationthe beige crystallizate was filtered off under suction
27. washwashed with 100 ml of tert.-butyl methyl ether
28. customdried for 1 hour in a high vacuum at 70° C

ORD record

ord-9667fef44aa3475f93e5eeb814147db7

Source dataset

uspto-grants-1996_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05488172