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Patent US4275241A successfully refreshed from Google Patents.
US4275241A
Expired / Lapsed
US
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Process for the preparation of 3-phenoxy-benzaldehydes
Assignee: Bayer AG
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Filing: 1979-10-29
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Granted: 1981-06-23
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Expires: 1999-10-29
Abstract
Abstract A process for the preparation of a-phenoxy-benzaldehyde which comprises contacting the 3-phenoxy-benzyl alcohol of the formula ##STR1## wherein R 1 and R 2 are identical or different and represent hydrogen or halogen with an aqueous solution of a dichromate in the presence of aqueous sulphuric acid at a temperature in the range of 50° to 125° C. The 3-phenoxy-benzaldehyde can be in a mixture of other organic compounds such as obtained by hydrolyzing a 3-phenoxy toluene chlorinated in the side chain at a temperature of 140°-210° C. under pressure.
Inventors
- 👤 Siegfried Bohm
- 👤 Alfons Klein
- 👤 Karlfried Wedemeyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:17
CPC Classifications
C; C07; C07C; C07C47/00; C07C47/52; C07C47/575; C07C45/00; C07C45/27; C07C45/29; C07C45/292; C07C45/78; C07C45/81; C07C45/82
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
58 words
A process for the preparation of a 3-phenoxy-benzaldehyde which comprises contacting the 3-phenoxy-benzyl alcohol of the formula ##STR6## wherein R 1 and R 2 are identical or different and represent hydrogen or halogen with an aqueous solution of a dichromate in the presence of aqueous sulphuric acid at a temperature in the range of 50° to 125° C.
Claim 2
Dependent Claim
58 words
A process for the preparation of a 3-phenoxy-benzaldehyde which comprises contacting the 3-phenoxy-benzyl alcohol of the formula ##STR6## wherein R 1 and R 2 are identical or different and represent hydrogen or halogen with an aqueous solution of a dichromate in the presence of aqueous sulphuric acid at a temperature in the range of 50° to 125° C.
Claim 3
Dependent Claim
23 words
A process according to claim 1 wherein the process is carried out at a temperature in the range of 80° to 100° C.
Claim 4
Dependent Claim
24 words
A process according to claim 1 wherein the process is carried out employing 2.5 to 10 mols sulphuric acid to 1 mol of dichromate.
Claim 5
Dependent Claim
22 words
A process according to claim 1 wherein the sulphuric acid is employed as a 10 to 70 weight percent aqueous sulphuric acid.
Claim 6
Dependent Claim
15 words
A process according to claim 1 wherein the dichromate employed is an alkali metal dichromate.
Claim 7
Dependent Claim
20 words
A process according to claim 1 wherein 0.25 to 0.4 mol of dichromate are employed per mol of benzyl alcohol.
Claim 8
Dependent Claim
18 words
Process according to claim 1 wherein a 10% by weight to saturated aqueous solution of dichromate is employed.
Claim 9
Dependent Claim
25 words
A process according to claim 1 wherein the process is carried out in the presence of an inert solvent which is not soluble in water.
Claim 10
Dependent Claim
105 words
A process for the preparation of a 3-phenoxy-benzaldehyde which comprises: (a) hydrolyzing a 3-phenoxy toluene, chlorinated in the said chain, having the formula ##STR7## wherein X 1 represents hydrogen or chlorine and R 1 and R 2 are identical or different and represent hydrogen or halogen by contacting the same in a first reaction stage with water at a temperature in the range of 140° to 210 ° C. under pressure; and (b) thereafter contacting the resultant product for step (a) with an aqueous solution of a dichromate in the presence of aqueous sulphuric acid at a temperature in the range of 50° 125° C.
Claim 11
Dependent Claim
105 words
A process for the preparation of a 3-phenoxy-benzaldehyde which comprises: (a) hydrolyzing a 3-phenoxy toluene, chlorinated in the said chain, having the formula ##STR7## wherein X 1 represents hydrogen or chlorine and R 1 and R 2 are identical or different and represent hydrogen or halogen by contacting the same in a first reaction stage with water at a temperature in the range of 140° to 210 ° C. under pressure; and (b) thereafter contacting the resultant product for step (a) with an aqueous solution of a dichromate in the presence of aqueous sulphuric acid at a temperature in the range of 50° 125° C.
Claim 12
Dependent Claim
25 words
A process according to claim 9 wherein step (b) is performed without isolation of any 3-phenoxy benzyl alcohol in the reaction product of step (a).
Claim 13
Dependent Claim
24 words
A process according to claim 9 wherein the hydrolysis of 3-phenoxy toluene chlorinated in the side chain takes place in a single reaction step.
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) | 1984-06-22 | 1984-12-22 | 1985-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-22 | 1988-12-22 | 1989-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-22 | 1992-12-22 | 1993-06-23 | $7700.00 | Window Closed / Lapsed |