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US4192959A
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Process for the preparation of pure 2-hydroxybenzyl alcohol, pure 4-hydroxybenzyl alcohol or a mixture of both hydroxy-benzyl alcohols
Assignee: HAARMANN and REIMER
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Filing: 1978-06-14
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Granted: 1980-03-11
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Expires: 1998-06-14
Abstract
Abstract A process for the preparation of pure 2-hydroxybenzyl alcohol, pure 4-hydroxybenzyl alcohol or a mixture of both hydroxybenzyl alcohols by reacting phenol and formaldehyde in the presence of a basic catalyst and subjecting the resulting reaction mixture to an at least 2-stage countercurrent extraction in a solvent system of water/organic solvent which is water-immiscible or water-miscible only to a limited extent.
Inventors
- 👤 Kurt Bauer
- 👤 Alfred Krempel
- 👤 Reiner Molleken
- 👤 Karlfried Wedemeyer
- 👤 Helmut Fiege
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:16
CPC Classifications
C; C07; C07C; C07C37/00; C07C37/68; C07C37/70; C07C37/72; C07C37/11; C07C37/20
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
179 words
A process for the preparation of pure 2-hydroxybenzyl alcohol and pure 4-hydroxybenzyl alcohol or a mixture of both compounds, which comprises reacting phenol with formaldehyde in the presence of about 0.05 to 0.0001 mol of a basic catalyst per mol of phenol at about 25° to 120° C. for about 0.5 to 5 hours to form a reaction mixture containing unreacted phenol, 2-hydroxybenzyl alcohol, 4-hydroxybenzyl alcohol, dihydroxydiphenylmethanes and polyhydroxymethylphenols, subjecting the resulting reaction mixture to countercurrent extraction in a solvent system of water/organic solvent, the organic solvent comprising an alkylaromatic compound with 7 or 8 C atoms, a cycloaliphatic hydrocarbon with 6 to 8 C atoms or an aliphatic ether with 6 to 8 C atoms, the system containing sufficient water to form an aqueous phase containing the 2- and 4-hydroxybenzyl alcohols and an organic phase comprising phenol and the dihydroxydiphenylmethanes, separating the organic phase, and in a second stage subjecting the aqueous phase to countercurrent extraction with an organic solvent to form an organic phase containing at least the 2-hydroxybenzyl alcohol and an aqueous phase containing the polyhydroxymethylphenols.
Claim 2
Dependent Claim
179 words
A process for the preparation of pure 2-hydroxybenzyl alcohol and pure 4-hydroxybenzyl alcohol or a mixture of both compounds, which comprises reacting phenol with formaldehyde in the presence of about 0.05 to 0.0001 mol of a basic catalyst per mol of phenol at about 25° to 120° C. for about 0.5 to 5 hours to form a reaction mixture containing unreacted phenol, 2-hydroxybenzyl alcohol, 4-hydroxybenzyl alcohol, dihydroxydiphenylmethanes and polyhydroxymethylphenols, subjecting the resulting reaction mixture to countercurrent extraction in a solvent system of water/organic solvent, the organic solvent comprising an alkylaromatic compound with 7 or 8 C atoms, a cycloaliphatic hydrocarbon with 6 to 8 C atoms or an aliphatic ether with 6 to 8 C atoms, the system containing sufficient water to form an aqueous phase containing the 2- and 4-hydroxybenzyl alcohols and an organic phase comprising phenol and the dihydroxydiphenylmethanes, separating the organic phase, and in a second stage subjecting the aqueous phase to countercurrent extraction with an organic solvent to form an organic phase containing at least the 2-hydroxybenzyl alcohol and an aqueous phase containing the polyhydroxymethylphenols.
Claim 3
Dependent Claim
60 words
A process according to claim 1, wherein the organic solvent in the second extraction is employed in such amount that the 4-hydroxybenzyl alcohol remains in the aqueous phase along with the polyhydroxymethylphenols and that aqueous phase is subjected to a third organic solvent extraction to form an organic phase containing the 4-hydroxybenzyl alcohol and an aqueous phase containing the polyhydroxymethylphenols.
Claim 4
Dependent Claim
63 words
A process according to claim 2 wherein there are used aliphatic ethers containing 6 to 8 C atoms or aliphatic ketones containing 5 to 6 C atoms in the second extraction stage and aliphatic ketones containing 5 to 6 C atoms, aliphatic esters containing 4 to 8 C atoms or aliphatic alcohols containing 4 to 8 C atoms in the third extraction stage.
Claim 5
Dependent Claim
34 words
A process according to claim 2 wherein the organic solvent used is toluene in the first extraction stage, diisopropyl ether in the second extraction stage and methyl isobutyl ketone in the third extraction stage.
Claim 6
Dependent Claim
38 words
A process according to claim 1 wherein the volume ratio V s /V w in the system of water/organic solvent which is water-immiscible or water-miscible to a limited extent used for the countercurrent extraction is 0.05 to 20.
Claim 7
Dependent Claim
20 words
A process according to claim 1 wherein the countercurrent extraction is carried out at temperatures from 20° to 70° C.
Claim 8
Dependent Claim
17 words
A process according to claim 1 wherein phenol is reacted with paraformaldehyde in the molar ratio 5-15:1.
Claim 9
Dependent Claim
17 words
A process according to claim 1 wherein phenol is reacted with paraformaldehyde in the molar ratio 8-12:1.
Claim 10
Dependent Claim
30 words
A process according to claim 1, wherein sufficient organic solvent is employed in the second extraction to extract the 4-hydroxybenzyl alcohol into the organic phase along with the 2-hydroxybenzyl alcohol.
Claim 11
Dependent Claim
22 words
A process according to claim 1, wherein unreacted phenol is removed from the resulting reaction mixture prior to the first extraction stage.
Claim 12
Dependent Claim
135 words
A process for the preparation of pure 2-hydroxybenzyl alcohol and pure 4-hydroxybenzyl alcohol or a mixture of both compounds which comprises reacting phenol with formaldehyde in the presence of about 0.05 to 0.0001 mol of a basic catalyst per mol of phenol at about 25° to 120° C. for about 0.5 to 5 hours to form a reaction mixture containing unreacted phenol, 2-hydroxybenzyl alcohol, 4-hydroxybenzyl alcohol, dihydroxyphenylmethanes and polyhydroxymethylphenols, subjecting the resulting reaction mixture to countercurrent extraction in a solvent system of water/aliphatic ketone containing 5 to 6 C atoms, the system containing sufficient water to form an aqueous phase containing substantially only the polyhydroxymethylphenols and an organic phase containing the balance, and subjecting the organic phase to a second countercurrent extraction with water to form an aqueous phase containing at least the 4-hydroxybenzyl alcohol.
Claim 13
Dependent Claim
135 words
A process for the preparation of pure 2-hydroxybenzyl alcohol and pure 4-hydroxybenzyl alcohol or a mixture of both compounds which comprises reacting phenol with formaldehyde in the presence of about 0.05 to 0.0001 mol of a basic catalyst per mol of phenol at about 25° to 120° C. for about 0.5 to 5 hours to form a reaction mixture containing unreacted phenol, 2-hydroxybenzyl alcohol, 4-hydroxybenzyl alcohol, dihydroxyphenylmethanes and polyhydroxymethylphenols, subjecting the resulting reaction mixture to countercurrent extraction in a solvent system of water/aliphatic ketone containing 5 to 6 C atoms, the system containing sufficient water to form an aqueous phase containing substantially only the polyhydroxymethylphenols and an organic phase containing the balance, and subjecting the organic phase to a second countercurrent extraction with water to form an aqueous phase containing at least the 4-hydroxybenzyl alcohol.
Claim 14
Dependent Claim
57 words
A process according to claim 11, wherein the water extraction is effected with only so much water that the 2-hydroxybenzyl alcohol remains in the organic phase, the organic phase then being subjected to a third countercurrent extraction with water to form an organic phase containing the 2-hydroxybenzyl alcohol and an aqueous phase containing the phenol and dihydroxydiphenylmethanes.
Claim 15
Dependent Claim
25 words
A process according to claim 11, wherein the water extraction is effected with sufficient water so that the aqueous phase also contains the 2-hydroxybenzyl alcohol.
Claim 16
Dependent Claim
25 words
A process according to claim 11, wherein methyl isobutyl ketone is used as the organic solvent which is water-immiscible or water-miscible to a limited extent.
Claim 17
Dependent Claim
22 words
A process according to claim 11, wherein unreacted phenol is removed from the resulting reaction mixture prior to the first extraction stage.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-03-11 | 1983-09-10 | 1984-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-03-11 | 1987-09-10 | 1988-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-03-11 | 1991-09-10 | 1992-03-11 | $7700.00 | Window Closed / Lapsed |