Hydrochloric Acid → (4-Hydroxyphenyl)phenylphosphinic acid
Reaction equation
Cl.C[O:3][C:4]1[CH:9]=[CH:8][C:7]([P:10]([C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)(=[O:12])[OH:11])=[CH:6][CH:5]=1.B(Br)(Br)Br>>[OH:3][C:4]1[CH:5]=[CH:6][C:7]([P:10]([C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)(=[O:11])[OH:12])=[CH:8][CH:9]=1Participants
4
Procedure
The latter compound is added dropwise to the reaction mixture which is maintained at 175° C. The mixture slowly darkens during this addition which is conducted over a period of about 2 hours. The reaction vessel is then allowed to cool and the reaction mixture purified. A total of 48 grams of ethyl bromide is collected, indicating the formation of about a 100% yield of ethyl p-methoxyphenylphenylphosphinate. The latter is hydrolyzed (by refluxing with concentrated HCl) to p-methoxyphenylphenylphosphinic acid and then demethylated by treatment with boron tribromide to give the desired p-hydroxyphenylphenylphosphinic acid, the starting material of Example 2.
Sources & evidence
- ORD record
- ord-281796bd61cc4092ab5cb0e9b4cd3f31
- Source dataset
- uspto-grants-1978_05
- Patent number
- US04087403
Reaction notes
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