AU605634B2 - Preparation of bis (amine-containing) benzenediols - Google Patents

Description

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PCT

INTERNATIONAL APPLI" WORLD INTELLCAL PROPERTY ORGANIZATION Int ernti onU l PBurePau IO NR (Pv 'Io Prgksrv UIoER| 4 E PATENT COOPERATION TREATY (PCT) (51) International Patent Classification International Publication Number: WO 89/ 00556 C07C 91/42, 87/28 A (43) International Publication Date: 26 January 1989 (26.01.89) (21) International Application Number: PCT/US88/02309 (81) Designated States: AT (European patent), AU, BE (European patent), CH (European patent), DE (Euro- (22) International Filing Date: 8 July 1988 (08.07.88) pean patent), DK, FI, FR (European patent), GB (European patent), IT (European patent), JP, KR, LU (European patent), NL (European patent), NO, SE (31) Priority Application Number: 071,241 (European patent).

(32) Priority Date: 9 July 1987 (09.07.87) Published (33) Priority Country: US With international search report.

Before the expiration of the time limit for amending the claims and to be republished in the event of the receipt (71) Applicant: THE DOW CHEMICAL COMPANY [US/ of amendments.

US]; 2030 Dow Center, Abbott Road, Midland, MI 48640 (US).

(72) Inventor: INBASEKARAN, Muthiah, N. 5800 Lamplighter, Midland, MI 48640 (US).

(74) Agent: KARADZIC, Dragan, The Dow Chemical P. A PR 198 Company, P.O. Box 1967, Midland, MI 48641-1967 A 1989

(US).

AUSTRALIAN

1 3 FEB1989 PATENT OFFICE (54) Title: PREPARATION OF BIS (AMINE-CONTAINING) BENZENEDIOLS (57) Abstract Bis (amine-containing) benzenediols are prepared by the hydrogenation and dehalogenation of bis (amine-containing) dihalobenzoquinones using formic acid, formate salts or mixtures thereof in the presence of a noble metal catalyst. An example of a compound produced by this process is 2,5-diamino-1,4-benzenediol. The benzenediols produced by the process of this invention are useful as monomers in the preparation of polybenzoxazoles of high thermal stability and compressive strength.

This document contains the amendmens made under Section 49 and is correct for pri ming.

I 8900556 PCT/US88/02309 WO 89/00556 -1- PREPARATION OF BIS (AMINE-CONTAINING) BENZENEDIOLS This invention relates to the hydrogenation of benzoquinone compounds. More specifically, it pertains to a process for the hydrogenation of bis (amine-con- S taining)'dihalobenzoquinone to produce bis (amine-containing) benzenediol.

Bis (amine-containing) benzenediols are useful as monomers in the preparation of polybenzoxazoles (PBO). Polybenzoxazoles can be prepared by reacting amine-containing benzenediols with bisacids, bisacid halides, bisesters or bisnitriles. Polybenzoxazole fibers have high tensile strength and thermal stability and are desirable for military, aerospace and other applications requiring rigid materials.

The known methods for preparing the benzenediol monomers typically involve a multi-step synthesis wherein expensive reagents are required and overall yield is poor. For example, one method involves oxidative bishydroxylation of hydroquinone with hydrogen peroxide and an alkali to produce zoquinone. The reaction of hydrogen chloride and methi- :r ~r.ll ;;iT 2 anol with the dihydroxybenzoquinone yields which is aminated with ammonia and then reduced with stannous chloride in concentrated hydrochloric acid to give 2,5-diamino-l,4-benzenediol with an overall yield of only about 20 percent. See R. Wolf, M. Okada and C.S.

Marvel, J. Polymer Science, Part A, 6, 1503 (1968). Other methods involve the reduction of a dihalodiaminobenzoquinone to the corresponding dihalodiaminohydroquinone without the elimination of the halogen substituents. See, U.S. Patent 4,337,196; Brit. 1,130,275 and Fr.

1,544,504.

A simple economical process is needed that would provide a high yield and allow both the reduction of the benzoquinone and the elimination of the halogen substitutents without the production of byproducts which are hazardous and difficult to dispose of properly. Such a process would allow the effective production of bis (amine-containing) benzenediol monomers for use in preparing the highly desirable polybenzoxazoles.

The present invention is such a straightforward and inexpensive one-step process that provides a high yield of bis (amine-containing) benzenediols. This process comprises contacting bis (amine-ccntaining) dihalobenzoquinones with a molar excess of a reducing agent selected from the group consisting of formic acid, a formate salt and mixtures thereof in the presence of a solvent and a noble metal-containing catalyst under .i reaction conditions such that the corresponding bis (amine-containing) benzenediol is produced in a single step. In this context, "amine-containing" refers to compounds having -NH 2 -NHR, or -NR 2 substituents wherein R is independently in each occurrence hydrogen,

C

1 10 alkyl,

I

S

C

KEH/0116f 1 ;i WO 89/00556 PCT/US88/02309 -3arylalkyl or alkylaryl. It has surprisingly been found that the process of the present invention results in a high yield and provides for reduction of the benzoquinone and elimination of the halogen substituents in a single step.

The bis (amine-containing) benzenediols so produced can be condensed with bisacids, bisacid halides, bisesters or bisnitriles to produce polybenzoxazoles.

Polybenzoxazole fibers, as indicated above, are highly useful in various industrial applications.

According to the process of the present invention, the benzoquinone starting material is contacted with formic acid, a formate salt or a mixture thereof in the presence of a solvent and a catalyst. The preferred benzoquinone compounds used as the starting material in the present invention correspond to the following general formula: (X-)2B-(NR1R2)2 wherein B is 1,4-benzoquinone; each X is independently chlorine, bromine, fluorine or iodine; and R1 and R 2 are independently hydrogen, C 1

_I

0 alkyl, arylalkyl or alkylaryl. It is preferred that X is chlorine and that

R

1 and R 2 are each hydrogen.

Typical benzoquinone compounds include -dichloro-3,6-diamino-1,4-benzoquinone; -3,6-diamino-1,4-benzoquinone; 2,5-dichloro-3,6- -bis(benzylamino)-1,4-benzoquinone; 2,5-dichloro-3,6- WO 89/00556 PCT/US88/02309 -4- -bis(methylamino)-1,4-benzoquinone; 2,5-dichloro-3,6- -bis(dimethylamino)-1,4-benzoquinone; 2,5-dichloro-3,6- -bis(ethylamino)-1,4-benzoquinone; with -3,6-diamino-1,,4benzoquinone; 2,5-dichloro-3,6-bis- (methylamino)-1 4-benzoquinone and 2,5-dichloro-3,6- -bis(benzylamino)-1,4-benzoquinone being preferred.

The most preferred benzoquinone starting material is 2,5-dichloro-3,6-diamino-1,4-benzoquinone. These benzoquinone starting materials can be prepared by methods well-known in the art. The typical preparation usually involves the reaction of excess ammonia or ammonium hydroxide with tetrahaloquinone. See, U.S. Patent 4,337,196.

U

A catalyst is advantageously employed in the practice of the present invention. The catalyst can be any material which contains a noble metal and will catalyze the conversion of the benzoquinone starting material in the presence of formic acid, a formate salt or a mixture thereof to the desired benzenediol. The catalyst may be unsupported or may be supported on supports well known in the art such as, for example, alumina, silica, zeolites, titania, alkaline earth metal carbonates or carbon. Examples of catalysts useful in the practice of the process of this invention include noble metals on carbon, noble metal oxides, and noble metals supported on alkaline earth carbonates. The term noble metals as used herein refers to gold, silver, platinum, palladium, iridium, rhodium, mercury, ruthenium and osmium. Preferred catalysts include palladium on carbon, platinum on carbon, and platinum oxide. The most preferred catalyst is palladium on carbon.

r WO 89/00556 PCT/US88/02309 The catalyst is employed in an amount which is isufficient to catalyze the conversion of starting material in the presence of formic acid, formate salts or mixtures thereof to the corresponding benzenediol.

Preferably, from 0.005 to 0.1 molar equivalents of catalyst are present per equivalent of benzoquinone starting material. More preferably, from 0.02 to 0.06 equivalents of catalyst are present throughout the reaction. It is preferred to add the catalyst to the reaction mixture under an inert atmosphere. Examples of inert atmospheres include argon, helium and nitrogen with nitrogen being preferred.

A solvent is advantageously employed in the process of the present invention. Solvents employed in the process of the present invention are polar solvents in which the benezenediol products are soluble.

Preferred solvents include water and low molecular weight organic polar compounds. Specific examples of preferred solvents include water, methanol, ethanol, propanol, dimethylformamide and dioxane. Water is the most preferred solvent. Preferably, from 1 to volumes of solvent are employed per volume of benzoquinone starting '.aterial. More preferably, from to 10 volumes of solvent are employed per volume of benzoquinone starting material.

Formic acid, formate salts or mixtures thereof are used in the process of the present invention as hydrogen transfer agents. When formic acid is used, it is preferred that it be aqueous formic acid. The concentration of the aqueous formic acid is preferably Sno less than 5 percent on a weight basis and no greater than 90 percent on a weight basis. It is more WO 8900556 PCT/US88/0230 9 -6preferred that it be no less than 20 percent on a weight basis and no greater than 60 percent. It is most preferred that the concentration of formic acid be percent on a weight basis.

Any formate salt which will function as a hydrogen transfer agent to reduce the benzoquinone and remove the halogens therefrom may be used in the practice of this invention. Preferred formate salts correspond to the formula

HCO

2

M

wherein M is Na, K, Ce, or (R 3 3 NH; and R 3 is hydrogen or hydrocarbyl. Examples of hydrocarbyl substituents useful in the practice of this invention include C 1 -6 alicyclic or aliphatic substituents. It is more pre- 2 ferred that M be (R 3 3 NH and that R 3 be hydrogen in each instance. The formate salt is preferably in a polar solvent. Representative examples of suitable polar solvents include water, lower alkanols, and acetic acid. It is preferred to use acetic acid as a solvent for the formate salt.

The hydrogen transfer agent is used in the practice of this invention in an amount sufficient for the reduction of the benzoquinone starting material to the benzenediol product and the removal of the halogen substituents on the benzoquinone starting material. It is preferred to use the reducing agent in a molar excess based on the molar amount of benzoquinone starting material that is used. It is more preferable 1O 89/00556 PCT/US88/02309 to use a 4 to 100 molar excess based on the hydroquinone. It is most preferable to use a molar excess of from 10 to 0 The reactants may be added in any order or S amount which will allow the reaction to proceed. It is preferred to first mix the benzoquinone reactant and the aqueous formic acid, formate salt or mixtures thereof and then to add the catalyst.

The process of the present invention can be carried out at any temperature and pressure at which the reaction will proceed. Preferably, the process is carried out at a temperature between 20 0 C and 1000C, more preferably between 400C and 700C. The process can be carrned out at sub- or superatmospheric pressures with atmospheric pressure being preferred for convenience.

0 The reaction may be allowed to proceed for any length of time sufficient to allow the conversion of at least 50 percent of the starting material. A total reaction time of from 10 minutes to 1 hour is preferred and from 10 minutes to 30 minutes is more preferred.

I Avery small amount of an additional reducing agent such as stannous chloride is added to the reaction mixture to prevent oxidation of the product. The product can be recovered using known recovery methods such as filtration. The product is generally isolated and stored as a hydrohalide salt in order to prevent oxidative decomposition. It is common practice to isolate the product as a salt of any mineral acid such as hydrochloric, sulfuric, nitric or phosphoric acid.

1 1 89P00556 CT/US88/02309 WO 89/00556 -8- The conversion of the benzoquinone starting material is at least 70 percent, preferably at least percent and more preferably at least 95 percent. The selectivity to the desired benzenediol is also at least percent, preferably at least 80 percent and more preferably at least 95 percent. Thus, the overall yield is at least 50 percent, preferably at least percent and more preferably at least 90 percent.

The process can be conducted in a batch or continuous mode.

Surprisingly, in the process of the present invention, the halogen atoms are removed from the benzoquinone ring system and the benzoquinone is converted to the corresponding benzenediol in a single step. The byproducts of the process are carbon dioxide and/or ammonia.

The benzenediol compounds prepared by the process of the present invention correspond to the following general formula:

OH

00

N(R

1

R

2 2

OH

pCT/US88/02309 WO 89/00556 -9wherein~-R and R 2 are as defined above. Typical benzenediols include 2,5-diamino-1,4-benzenediol, -bis(benzylamino)-1,4-benzenediol, -amino)-1,4-benzenediol, 2,5-bis(ethylamino)-1,4- -benzenediol, with 2,5-diamino-1,4-benzenediol, -bis(methylamino)-1,i-benzenediol and amino)-1,4-benzenediol being preferred. The most preferred benzenediol is 2,5-diamino-1, 4 -benzenediol.

The following examples are given to illustrate the invention. Unless stated otherwise, all percentages and proportions are given on a weight basis.

Example 1 -Preparation of 2,5-diamino-1,4-benzenediol Using Formic Acid A 400-mg portion of a 10 percent palladium-on- -carbon catalyst was added to a reaction vessel containing a vigorously stirred suspension of 4.14 g mmole) of 2,5-dichloro-3,6-diamino-1,4-benzoquinone in 30 ml of water and 20 ml of 88 percent formic acid under a nitrogen atmosphere. The nitrogen was removed and mixture was stirred and heated to 600C during a period. The mixture was kept at 60°C for minutes. About 50 mg of stannous chloride was added and the mixture was filtered and washed with 15 ml of water. Hydrogen chloride gas was passed into the filtrate to saturation. The mixture was cooled overnight and the colorless needles of 2,5-diamino-1,4-benzenediol as the bishydrochloride salt were filtered and washed with ethanol and water in a yield of 4.14 g or 98 percent based on the benzoquinone. The product is, S8 CT/US88/02309 w WO 89/00556 confirmed by proton magnetic resonance to be diamino-1,4-benzenediol.

Example 2 Preparation of 2,5-diamino-1,4-benzenedidl Using Formate Salt A 400-mg portion of a 10 percent palladium-on- -carbon catalyst was added to a reaction vessel containing a vigorously stirred suspension of 1.40 g (7 mmol) of 2,5-dichloro-3,6-diamino-1,4-benzoquinone, 3.15 g (50 mmol) of ammonium formate, 20 ml of water and 5 ml of acetic acid under a nitrogen atmosphere.

The nitrogen was removed and the mixture was stirred at 2] ambient temperature for one hour. The mixture was then heated and stirred at 60°C-80 0 C for 2 hours. About mg of stannous chloride and 10 ml of HC1 was added and the catalyst was filtered off. Then 20 ml of concentrated HC1 was added to the filtrate. The filtrate was cooled overnight and the colorless needles of 2,5-diamino-1,4-benzenediol as the bishydrochloride Q 0 salt were filtered and washed with ethanolCand water.

The yield was 1.4 g or 98 percent based on the benzoquinone starting material. The product was 2 |determined by elemental analysis and proton magnetic Sresonance to be 2,5-diamino-1,4-benzenediol.

These examples demonstrate that the process of the present invention is a simple and efficient method capable of producing surprisingly high yields of bis (amine-containing) benzenediols.

Claims (13)

1. A process for the preparation of bis (amine-containing) benzenediols comprising contacting a bis (amine-containing) dihalobenzoquinone with a molar excess of a reducing agent selected from the group consisting of formic acid, a formate salt and mixtures thereof in the presence of a solvent and a noble metal-containing catalyst under reaction conditions ,such that the corresponding benzenediol is produced in a single step.

2. The process of Claim 1 wherein the benzoquinone starting material corresponds to the following general formula: 2 B-(NR 1 R 2 2 wherein B is 1,4-benzoquinone, X is chlorine, bromine, fluorine or iodine and R and R 2 are independently hydrogen, C1- 10 alkyl, arylalkyl or alkylaryl.

3. The process of Claim 1 or Claim 2 wherein the molar excess of reducing agent is between 4 and 100 based on the benzoquinone starting material.

4. The process of any one of Claims 1 to 3 wherein a polar solvent is employed.

The process of any one of Claims 1 to 4 wherein the catalyst is a noble metal supported on an alkaline earth carbonate.

6. The process of any one of Claims 1 to 4 wherein tie catalyst is a noble metal supported on carbon.

7. The process of any one of Claims 1 to 6 wherein the catalyst is present in from 0.005 to 0.1 molar equivalent based on the benzoquinone starting material.

8. The process of Claim 4 wherein the solvent is water.

9. The process of Claim 6 wherein the catalyst is palladium-on-carbon.

A process of any one of Claims 1 to 9 wherein bis (amine- containing) benzenediol is produced with a selectivity of at least percent and a conversion of at least 70 percent based on the starting bis(amine-containing) d1halobenzoquinone.

11. A process for the preparation of bis (amine-containing) _J r I' Y I' ICLIIIII-I- ~-YUIXrI~~l*~~~-iliiiii_~i? L-l 1111l1r1;11 12 benzenediols, which process is substantially as herein described with reference to Example 1 or Example 2. DATED this ELEVENTH day of OCTOBER 1990 The Dow Chemical Company Patent Attorneys for the Applicant SPRUSON FERGUSON 0 0 S S. OS S 0* 0 _KEH/0116f I i "j INTERNATIONAL SEARCH REPORT International Application NPCT/US88/02309 I. CLASSIFICATION OF SUBJECT MATTER (it several classification symbols apply, Indicate all) 6 According to Internalional Patent Classification (IPC) or to both National Classification and IPC IPC(4): C07C 91/42, 87/28 U.S.C1.: 564/443; 564/384 II. FIELDS SEARCHED Minimum Documentation Searched 7 Classification System Classification Symbols U.S. 564/443; 564/384 Documentation Searched other than Minimum Docum *ntation to the Extent that such Documents are Included in the Fields Searched 8 III DOCUMENTS CONSIDERED TO BE RELEVANT 9 Category Citation of Document, 11 with indication, where appropriate, of the relevant passages

12 Relevant to Claim No.

13 Y,P US, A, 4,692,554 (YAMAGUCHI ET AL) 08 1-10 September 1987. col. 4, line 17- col. 6 and claims 2 and 3. Y US, A, 4,337,196 (BACKLUND ET AL), 29 June 1-3,10 1982, col. 2 reaction col. line 37, col. 6, line 24. Y US, A, 4,581,349 (WRIGHT), 08 April 1986, 1-3,6, col. 5, Scheme B, first step of 7.9 reaction. Y The Merck Index, Tenth Edition. 1983 1-10 page 605 "Formic Acid". P,Y WO, A, 87/06930 (INBASEKARAN), 19 November 1-10 1987, see entire document. SSpecial categories of cited documents: 10 later document published after the international filing date or priority date and not in conflict with the application but document defining the general state of the art which is not orpri it date and t h e t pr i nco p l e ict th e o r y u n d e rlying the considered to be of particular relevance invention earlier document but published on or after the international document of particular relevance; the claimed invention filing date cannot be considered novel or cannot be considered to document which may throw doubts on priority claim(s) or involve an inventive stip which is cited to establish the publication date of another Y" document of particular relevance; the claimed Invention citation or other special reason (as specified) cannot be considered to Involve an inventive step when the document referring to an oral disclosure, use, exhibition or document is combined with one or more other such docu- other means ments, such combination being obvious to a person skilled document published prior to the international filing date but In the art, later than the priority date claimed document member of the same patent family IV. CERTIFICATION Date of the Actual Completion of the International Search Date of Mailing of this International Search Report 17 OCTOBER 1988 30 NOV 1988 International Searching Authority Signat r f Authorized Offce ISA/US I SUSAN P. TREANOR' Form PCT/ISA210 (sacond sheet) (Rev.11-87) International Application No. PCT/US88/02309 FURTHER INFORMATION CONTINUED FROM THE SECOND SHEET Chemical Abstracts, Volume 96, No. 13, issued 29 March 1982 (Columbus, Ohio. USA), M. Pardo et al, "Synthesis and Structure of Phenylazo-hydroquinones", see page 663, cols. 1 and 2 of abstract no. 103770n- Liebigs Ann. Chem. 1982 (1)r pp. 99-111 (Ger.) 1-10 OBSERVATIONS WHERE CERTAIN CLAIMS WERE FOUND UNSEARCHABLE' This international search report has not been established in respect of certain claims under Article 17(2) for the following reasons: Claim numbers because they relate to subject matter i not required to be searcheC by this Authority, namely: 2.1 Claim numbers because they relate to parts of the international application that do not comply with the prescribed require- ments to such an extent that no meaningful International search can be carried out 13, specifically: 3. Claim numbers because they are dependent claims not drafted in accordance with the second and third sentences of PCT Rule 0.4(a). VI.] OBSERVATIONS WHERE UNITY OF INVENTION IS LACKING 2 This International Searching Authority found multiple inventions in this international application as follows: 1.r As all required additional search fees were timely paid by the applicant, this international search report covers all searchable claims of the International application. As only some of the required additional search fees were timely paid by the applicant, this international search report covers only those claims of the international application for which fees were paid, specifically claims: 'o required additional search fees were timely paid by the applicant. Consequently, this international search report Is restricted to the invention first mentioned In the claims; it is covered by claim numbers: As all searchableclaims could be searched without effort justifying an additional fee, the International Searching Authority did not invite payment of any additional fee. Remark on Protest SThe additional search fees were accompanleL by applicant's protest. 5 No protest accompanied the payment of additional search fees. Il SPCTSA'210 IsupPlmrUu rh (Fla. 11-87) I International Application No. PCT/US88/0 2309 Ill. DOCUMENTS CONSIDERED TO BE RELEVANT (CONTINUED FROM THE SECOND SHEET) Category II Citation of Document. wil indication, where appropriate, of the relevant passagies Relevan't to Claim No Journal of the American Chemical Society, Volume 68, pp. 261-265 (1946), R. Baltzly et al, "The Catalytic Hydrogenolysis of Halogen Compounds". Helvetica Chimica N.cta Volume 39, No. 38, pp. 335-340 (1956), A. Marxer, "138. tUbe r 2, see page 337 at 3, 6-Dichlor-2, (XIII). 1-10 1-10 iform PCT/i~IM10 (sWe shsa) (Rev.t 1471)