Patent US4273941A successfully refreshed from Google Patents.
US4273941A
Expired / Lapsed
US
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Process for producing p-hydroxybenzaldehyde
Assignee: Sumitomo Seika Chemicals Co Ltd
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Filing: 1979-07-06
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Granted: 1981-06-16
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Expires: 1999-07-06
Abstract
Abstract A process for producing p-hydroxybenzaldehyde through p-aminobenzaldehyde from p-nitrotoluene, comprising reacting p-nitrotoluene with sodium polysulphide in an alcohol-alkali aqueous solution mixed solvent in the presence or absence of an aprotic polar compound to produce p-aminobenzaldehyde, diazotizing the p-aminobenzaldehyde and then hydrolyzing the diazotized p-aminobenzaldehyde to produce p-hydroxybenzaldehyde.
Inventors
- 👤 Masao Kawamura
- 👤 Tadaaki Nishi
- 👤 Kunioki Kato
- 👤 Hiroshi Mizokami
- 👤 Tadashi Kanazawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:54
CPC Classifications
C; C07; C07C; C07C45/00; C07C45/61; C07C45/64
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
41 words
In a process for producing p-aminobenzaldehyde from p-nitrotoluene comprising reacting p-nitrotoluene with sodium polysulphide in a mixed solvent consisting of at least one alcohol and an alkali aqueous solution in the presence of an aprotic polar compound to produce the p-aminobenzaldehyde.
Claim 2
Dependent Claim
41 words
In a process for producing p-aminobenzaldehyde from p-nitrotoluene comprising reacting p-nitrotoluene with sodium polysulphide in a mixed solvent consisting of at least one alcohol and an alkali aqueous solution in the presence of an aprotic polar compound to produce the p-aminobenzaldehyde.
Claim 3
Dependent Claim
36 words
A process according to claim 1, wherein the at least one alcohol is a member selected from the group consisting of methanol, ethanol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and mixtures thereof.
Claim 4
Dependent Claim
20 words
A process according to claim 1, wherein the at least one alcohol contains at least 80% by weight of ethanol.
Claim 5
Dependent Claim
22 words
A process according to claim 1, wherein the aprotic polar compound is used in an amount of 0.01-10% by weight of p-nitrotoluene.
Claim 6
Dependent Claim
28 words
A process according to claim 1, wherein the aprotic polar compound is a member selected from the group consisting of N,N-dimethylformamide, N,N-diethylformamide, N,N-diphenylformamide, dimethylsulfoxide, tris(trimethylamino)phosphate, tetrahydrofuran and acetonitrile.
Claim 7
Dependent Claim
25 words
A process according to claim 1, wherein the sodium polysulphide is represented by the formula Na 2 Sx wherein x is an integer of 2-5.
Claim 8
Dependent Claim
25 words
A process according to claim 5, wherein the sodium polysulphide is represented by the formula Na 2 Sx wherein x is an integer of 2-5.
Claim 9
Dependent Claim
55 words
A process according to claim 1, wherein the sodium polysulphide is one prepared by reacting sodium hydroxide in aqueous solution with hydrogen sulphide to produce sodium hydrosulphide, reacting the thus produced sodium hydrosulphide with sodium hydroxide to produce sodium sulphide and then reacting the thus produced sodium sulphide with sulphur to produce the sodium polysulphide.
Claim 10
Dependent Claim
26 words
A process according to claim 8, wherein the reaction of sodium hydroxide in aqueous solution with hydrogen sulphide is effected at a temperature of 10°-60° C.
Claim 11
Dependent Claim
22 words
A process according to claim 8, wherein the sodium hydrosulphide is incorporated with the sodium hydroxide in a molar ratio of 1.0-3.0.
Claim 12
Dependent Claim
82 words
A process for producing a diazonium salt of p-aminobenzaldehyde from p-nitrotoluene comprising the steps of: reacting p-nitrotoluene with sodium polysulphide in a mixed solvent consisting of at least one alcohol and an alkali aqueous solution in the presence of an aprotic polar compound to produce p-aminobenzaldehyde, adding the thus produced p-aminobenzaldehyde to an aqueous solution of sulphuric acid at 60°-100° C. to produce the sulphate thereof rapidly, and diazotizing, after cooling, the thus produced sulphate to produce a diazonium salt of p-aminobenzaldehyde.
Claim 13
Dependent Claim
82 words
A process for producing a diazonium salt of p-aminobenzaldehyde from p-nitrotoluene comprising the steps of: reacting p-nitrotoluene with sodium polysulphide in a mixed solvent consisting of at least one alcohol and an alkali aqueous solution in the presence of an aprotic polar compound to produce p-aminobenzaldehyde, adding the thus produced p-aminobenzaldehyde to an aqueous solution of sulphuric acid at 60°-100° C. to produce the sulphate thereof rapidly, and diazotizing, after cooling, the thus produced sulphate to produce a diazonium salt of p-aminobenzaldehyde.
Claim 14
Dependent Claim
26 words
A process according to claim 11, wherein the aqueous solution of sulphuric acid contains sulphuric acid in a concentration of 2-50% by weight of the solution.
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) | 1984-06-15 | 1984-12-15 | 1985-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-15 | 1988-12-15 | 1989-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-15 | 1992-12-15 | 1993-06-16 | $7700.00 | Window Closed / Lapsed |