EP0335524A2
Expired / Lapsed
EP
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Process for the preparation of indigo compounds
Assignee: Mitsui Toatsu Chemicals Inc
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Filing: 1989-03-15
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Granted: —
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Expires: 2009-03-15
Abstract
Abstract An indigo compound is prepared by reacting an indole compound unsubstituted in the 2- and 3-positions, with hydrogen peroxide in a liquid phase comprising an organic liquid. In one aspect, the liquid phase comprises at least two separate phases including an organic phase containing the indole compound and an aqueous phase containing hydrogen peroxide; in another aspect, the hydrogen peroxide is in solution in an organic solvent.
Inventors
- 👤 Usaji Takaki
- 👤 Shinobu 2-11 Mitsui Toatsu Kosugaya Apaato Aoki
- 👤 Yoshihiro 1-33 Mitsui Toatsu Apaato Yamamoto
- 👤 Isao 4-18 Mitsui Toatsu Apaato Hara
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 08:41
CPC Classifications
C; C07; C07D; C07D209/00; C07D209/02; C09; C09B; C09B7/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
32 words
A process for the preparation of an indigo compound which comprises reacting an indole compound unsubstituted in the 2- and 3-positions, with hydrogen peroxide in a liquid phase comprising an organic liquid.
Claim 2
Dependent Claim
32 words
A process for the preparation of an indigo compound which comprises reacting an indole compound unsubstituted in the 2- and 3-positions, with hydrogen peroxide in a liquid phase comprising an organic liquid.
Claim 3
Dependent Claim
54 words
A process as claimed in claim 1 for the preparation of an indigo compound which comprises reacting an indole compound unsubstituted in the 2- and 3-positions, with hydrogen peroxide in a liquid phase comprising at least two separate phases including an organic phase containing the indole compound and an aqueous phase containing hydrogen peroxide.
Claim 4
Dependent Claim
20 words
A process as claimed in claim 2, wherein the reaction is carried out in the presence of an organic solvent.
Claim 5
Dependent Claim
27 words
A process as claimed in claim 2 or claim 3, wherein the concentration of hydrogen peroxide in the aqueous phase is from 1 to 70% by weight.
Claim 6
Dependent Claim
35 words
A process as claimed in claim 1 for the preparation of an indigo compound which comprises reacting an indole compound unsubstituted in the 2- and 3-positions, with hydrogen peroxide in solution in an organic solvent.
Claim 7
Dependent Claim
24 words
A process as claimed in claim 5, wherein the concentration of hydrogen peroxide in the organic solvent is from 0.001 to 50% by weight.
Claim 8
Dependent Claim
18 words
A process as claimed in any one of claims 2 to 6, wherein the organic solvent is aprotic.
Claim 9
Dependent Claim
40 words
A process as claimed in claim 7, wherein the aprotic solvent is selected from aliphatic and alicyclic hydrocarbons, aromatic hydrocarbons, alkyl substituted aromatic hydrocarbons, aliphatic and aromatic halogen compounds, ethers, ketones, esters, carbonates, aliphatic and aromatic nitro compounds, and nitriles.
Claim 10
Dependent Claim
35 words
A process as claimed in any one of claims 1 to 8, wherein the indole compound is selected from indole, alkylindoles, halogenated indoles, hydroxyindoles, halogenated alkylindoles, nitroindoles, indolecarboxylic acids and esters thereof, and sulfonated indoles.
Claim 11
Dependent Claim
30 words
A process as claimed in any one of claims 1 to 9, wherein hydrogen peroxide is used in an amount of 0.01 to 100 moles per mole of indole compound.
Claim 12
Dependent Claim
25 words
A process as claimed in any one of claims 1 to 10, wherein the reaction is carried out at a temperature from -10° to 140°C.
Claim 13
Dependent Claim
20 words
A process as claimed in any one of claims 1 to 11, wherein the reaction time is within 50 hours.
Claim 14
Dependent Claim
34 words
A process as claimed in any one of claims 1 to 12, wherein the indigo compound is recovered from the reaction mixture in the form of a solid according to a solid-liquid separation technique.
References Cited (Backward Citations)
No citation records indexed.
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