CA1036612A - Pyrocatechol ethers - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
New and valuable pyrocatechol ethers having the formula

Description

103661Z o.z. 29,~8~ -PYROCATECHOL ETHERS
The present invention relates to new and valuable pyrocate-chol ethers and processes for their production.
German Patent No. 566,033 discloses that alcoholic or phenolic hydroxyl groups are capable o~ reacting with vinyl ~r l-halo- ` ;
ethers with the ~ormation of acetals which are stable to alkali (cf. also Houben-Weyl, "Methoden der organischen Chemie", -volume 6/3, pages 186 and 229).
It is also known (for example ~rom B~J.Chem.Soc., 1927, 1664;
US Patent No. 3,202,573) that in an attempt to carry out a partial alkylation of only one hydroxyl group of pyrocatechol this latter and the alkylating agent are lost in considerable quantities due ~ :
to the formation, as byproduct, of the non~ploitable diether.
We have ~ound that the valuable new ethers o~ pyrocatechol having the ~ormula (I): OH Rl ~ -o-C-oR3 in which R is hydrogen or lower alkyl (Cl to C~);
R2 is unsubstituted or substituted (by halo~en (Cl, Br, I), methoxy or ethoxy) lower alkyl (Cl to C3) or benzyl;
R3 is alkyl (Cl to C4), cycloalkyl (C3 to C7), ~-chloroethyl, alkoxyalkyl (methoxyethyl, ethoxyethyl), alkenyl (up to C4), alkynyl (up to C4), aoyl (acetyl); and moreover Rl and R2 to-gether wlth the carbon atom whose substituents they are and , ., ~ ''' ' .

o.z. 29,484 1(~3~i61Z
also Rl and R3 together with the carbon or oxygen atom whose substituents they are, ~orm a ~ive-membered or six-membered ring (cyclopentyl, cyclohexyl, tetrahydro~uranyl, tetrahydropyranyl) are obtained in a simple manner and excellent yields when pyro-catechol is reacted with pre~erably the amount required for ether-ification of one hydroxyl group of pyrocatechol, or up to about a 50% excess or deficiency o~ this amount, of a vinyl ether o~
the formula: 3 R-OR
where R is vinyl or vinyl bearing lower alkyl (up to C3) as a substituent and R3 has the above meanings, with or without the addition o~ a catalytically-acting substance such as an acid-reacting substance, e.g. a mineral acid, acid salt, organic acid, d~-haloether, organic or inorganic acid chloride, an ion exchanger or a Lewis acid, ~or example AlCl~, FeCl3, BF3 and the like, in a temperature range o~ ~rom -5C to 120C and pre~erably at 40 to 50C and/or with the addition of a solvent or diluent which is inert to the reactants, ~or example an ether (diethyl ether, tetrahydro~uran, dioxane), a hydrocarbon t~or example n-hexane, benzene, toluene or xylene), halohydrocarbon (CH2Cl2, CHC13 or 20 cCl 4 ) .
The new compounds are important intermediates for the production of active ingredients for plant protection ~gents and pharmaceutical and veterinary produots.
I~ pyrocatechol is reacted wlth vinyl methyl ether, the reaction may be illustrated by the following equation:

; ~ +HC-O-CH3 cata~st ~ CH

-2-': ,: ' ' -O.Z. 29,4841036612 The abovementioned compounds are preferably used as catalysts.
The products according to the invention may also be prepared by reaction of preferably equimolar amounts or an excess or de-ficiency of up to about 50~ of an l-haloester of the formula: -Rl .
Hal-C-OR3 , where Hal is Cl, Br or I and the radicals R1, R2 and R~ have the above meanings, with a salt of pyrocatechol or with pyrocatechol ;
in the presence of an organic or inorganic base (for example an alcoholate, alkali metal hydroxide, alkaline earth metal hydroxide or suitable amIne~ or a substance having an alkaline reactionJ such as an alkali or alkaline earth metal carbonate.
The followln~ equation illustrates the reaction:

~ + C1-C-OR -HCl ~ O-C-OR

The radicals R1, R2 and R3 have the above meanings. It is preferred to dilute the reactants with a solvent, for example from 5 to 80% by weight of an ether (diethyl ether, tetrahydro-furan) or an aromatic hydro¢arbon (benzeneJ toluene, xylene).
The vinyl ethers and l-haloethers used for the reaction are known from the llterature and are also readily prepared industrially (cf. for example W. Reppe et al., Ann., 601, (1956), 98.
Depending on the excess of vinyl ether or l-haloether used in 20 the abovementioned processes there are formed corresponding amounts of new bisethers of the formula (II). ~ -O . Z . 29J 484 ' o 3 ~2 R
(II).

-C -R

me radicals R1, R2 and R3 have the above meanings.
The abovementioned bisethers may be prepared in quantitative yields preferably by reaction o~ pyrocatechol with at least twice the molar amount of a vinyl ether.
The catalysts and reaction conditions as regards temperature and solvents are analogous to those given for the production of compounds of formula (I).
Another process for the production of compounds of the formula (I) consists in reacting a bisether of the formula (II) with pyro-catechol according to the following equation:

o-l-oR3 OH OH
l ~ ~ cata~st)2 ~ o-C-oR3 o -C - oR3 R2 (II) (I) The radicals R1, R2 and R3J the catalysts and the reaction conditions are the same as in the production of compounds of the formula (I) from vinyl ethers.
The new pyrocatechol derivatives of the formulae (I) and (II) are obtained in the form of colorless oils which after stabilization :

with organic or inorganic bases can be distilled in vacuo without --4- ;

~"''' '' ~':
~ .

! . ' . :. . .. ,. ~, . :

O.Z. 29,484 ~036~ 2 decomposition. Compounds ~ ich may be prepared by the process of the invention are listed below:
Formula (I):

-C-OR

Rl R2 R3 bp C; n25 :
D
H H CH3 bp(o,4 mm) 89 to 93 H H C2H5 bp(o 1 mm): 9 to 100 H CH3 CH3 P(.5 mm): 85 to 9o :

H CH3 C2H5P(l mm) 78 to 81 :.
CH3 n~C3H7bp(l mm): 96 to 98 H CH3 3 7bp(l mm): 89 to 94 H CH~; i-C4Hg P(0.2 mm) 9 9 H 3 ~3 bp(o 2 mm): 128 to 135 H CH3 -(~ bp(4 mm): 132 to 136 CH3 COCH3 nD5: 1.50'15 CH3 COC2H5 nD25: 1.4905 H CH3 -CH2-CH=CH2 5 ~ ~ .

.... .

1~3661Z o.z. 29~484 Rl R2 R3 bp C; n25 H CH3 -CH2-C=CH

HCH2Cl -CH3 nD5: 1.5135 HCH2Cl -C2H5 nD5: 1.5146 HCH2Cl -CH2-CH2Cl nD5: 1.4975 HCH2Cl COCH3 nD5: 1.5012 HCH2Br CH3 nD5: 1.5340 C2 5 CH3 bp(l 5 mm): 105 to 113 2 5 C2H5 bp(o 5 mm): lOO to 103 C2 5 CH2-C=CH
H CH2-CH2Cl CH3 ~ 5: 1.5023 CH2-CHcl-cH3 3 H CH2-CHBr-CH3 3 H CH2-CHCl-C2H5 CH3 ~ .
H n-C3H7 3 ~
-6- ~ :
~, ~

O.Z. 29,484 Rl R2 R3 bp C; n25 - :
- .
H i-C3H7 3 H CH=CH2 3 H CH2- ~ 3

3 3 CH3 bp (0.3 mm): 95 to 100 CH3 CH2Cl CH3 nD5: 1.5024 CH3 CH2Cl 2 5 CH3 CH2Br 3 CH3 CH2Br 2 5 3 3 7 CH~
CH3 i-C3H7 3 ~ ~ R1 bp (0.5 mm) : 115 to 118 Formula (II) o-C-oR3 [~< F~l ' '.
o-c-oR3 R2 ':, , .
: : .
' ' O.Z. 29,484 Rl R2 R3 bp C
.
H H CH~ bp(o 4 mm): 105 to 109 H CH~ CH3 bp(o,5 mm): 99 to 105 H CH3 C2H5 P(0.3 mm) 97 H CH3 i-C4Hg bp(o 3 mm): 124 to 128 The new compounds are o~ great importance as precursors ~or plant protection agents and pharmaceutical products.
~ or example by reaction of compounds o~ ~ormula (I) with methyl isocyanate, active substances may be prepared which have a good insecticidal action both on biting and sucking insects and outstanding effectiveness against red spiders and ticks. At the same tlme they have only slight phytotoxicity. The action is rapid and prolonged. For this reason the active substances may be used successfully in plant protection ~or cont~aling in~urious sucking ! lo and biting insects and Diptera and for combatting mites (Acarina) both in this and the veterinary ~'ield. In this context emphasis , may be placed on the excellent ef~ectiveness of the active sub-stances against strains of red spiders which are resistant to phosphoric esters. ~;
The following examples illustrate the invention.
.. . ..
, EXAMPLÆ l !l o-(l-methoxv)-ethoxy~hen~l-N-meth~l carbamate:

34 parts by weight o~ o-(l-methoxy)-ethoxyphenol is dissolved in 100 parts by weight of toluene. 12 parts by weight o~ methyl , isocyanate is poured in all at once. 2 drops of triethylamine are added and the whole is le~t to stand overnight. The whole is then -8- - ~;
, ~ :;: ': ' .:

`

: - . - ., .. , .. . :, . ,, . ,~ .

lQ3661Z o. z . 29, l~84 concentrated and to the oily residue there is added 100 parts by weight of a mixture of equal parts of toluene and ligroin.
33 parts by weight of colorless crystals are precipitated upon cooling. After recrystallization these crystals melt at 97 to 99C. ' ' - ' o-(1-ethox~)-ethoxyphen~l-N-meth~l_carbamate_ 33.4 parts by weight of pyrocatecholmono-N-methyl carbamate is suspended in 100 parts by weight of toluene. 3 drops of con-centrated hydrochloric acid are added and then 15 parts by weight of vinyl ethyl ether is dripped in over a period of ten minutes.
The whole is stirred for one hour at 80C. After cooling the product is washed with 50 parts by weight of 3% sodium bicarbonate solution and dried over sodium sulfate, and the solvent is re-moved. A colorless oil remains which is taken up in 100 parts by weight of a mixture of equal parts of toluene and ligroin. 31 parts by weight of carbamate crystallizes out in the deep freezer. After recrystallization the melting point is 62 to 63C.
The substances set out in the ~ollowing Table may be obtained in a similar manner: 0-C0 ¦ CH~

~ -o-C-R5 R7 R4 R5 R6 mp C
H CH~ H i-C3H7 40 to 45 C2H5 H CH3 88 to 90 -H C2H5 ~2H5 52 to 54 O.Z. 29,484 1~;)3661Z
R7 R4 R5 R6 mp. C

H n-C4Hg H CH3 H n-C4Hg H C2H5 H i-C4Hg H CH3 n C4 11 H CH3 CH3 CH3 CH3 80 to 82 Other new active substances areCHas follows:

~3 o\6~5 ~ ~

7 R4 R5 R6 mp. C (n25) .
l H H CH2Cl C2H5 (1-5125) H H CH2Cl COCH3 (1.5119) CH3 H CH2Cl C2H5 (1.5205) CH3 H CH2Br C~ (1.5310) H H CH2Br CH3 70 to 72 H CH2I CH3 (1.5465) -,~ -10- ' :' ,:

O.Z. 29,484 1~}3661Z ~:
R7 R4 R5 R6 mp C (n25) H H CH2-CH2Cl CH3 65 to 66 CH3 H CH2-CH2C1 3 :-H H CHCl-CH3 3 H H CHBrCH3 CH30 H H CH2-CH2Br CH3 H H CH20cH3 3 H H CH2-CH2-oCH3 CH3 (1.5184) H H CH(OCH3)-CH3 3 CH3 CH2Cl CH3 106 to 108 CH3 CH3 CH2Cl CH3 H CH3 CH2Br 3 3 CH3 CH2Br 3 .

(a) o-(l-methoxyethox~-phenol: .
110 parts by weight o~ pyrocatechol is suspended in 100 .:
parts by weight of' toluene. At +5C 64 parts by weight of vinyl methyl ether which has a temperature of` -40C is poured in all at once and then 1 drop of' concentrated hydrochloric ac~d is added.
The whole is heated to about 120c while stirring, whereupon the reaction commences and the temperature o~ the contents o~ the ~lask rises to about 65C. External cooling with ice-water may --11- .

~ O.Z. 29J48l~

be applied if necessary. me whole is kept ~or half an hour at 65C and then 5 parts by weight of 2-normal caustic soda solution is added. The whole is cooled, and dried by means o~ sodium sulfate, and the solvent is evaporated in a rotary evaporator.
The product is distilled in vacuo. The yield is 155 parts by weight. The boiling point is 85 to 90C at 0.5 mm.
Analysis: CgH120~ (168) calculated: C 64.1 H 7.2 found: C 64.4 I~ 7.0 (b) pyrocatechol-bis- L(l-methoxy)-ethyl]-ether:

.
The reaction described under (a) is repeated but with twice the amount (128 parts by weight) o~ vinyl methyl ether. 122 parts by weight of a colorless oil is obtained having a boiling point o~ 99 to 105 C at 0.5 mm. Analysis: C12H1804 (226) calculated: C 6~.7 H 8.0 -found: C ~3.~ H 8.1.
(c) o-(l-methox~ethox~)-phenol:
0.5 parts o~ SOCl2 is added to 113 parts by weight o~ pyro-catechol-bis-~1-methoxy)-ethyl]-ether and 55 parts by weight o~
pyrocatechol at 40C and the whole is stirred at this temperature for hal~ an hour. It is then allowed to cool and 2 parts by 20 volume of 25% by weight aqUeoUs caustio soda solution ls added.
The product is separated and dried over sodium sulfate and the solvent is evaporated. There remains 168 parts o~ the abovemen-tioned compound having a boiling point o~ 85 to 90C at 0.5 mm.

(a) o-(l-ethox~ethoxy~-phenol:
220 parts by weight o~ pyrocatechol is suspended in 200 parts by weight of toluene. A~ter 2 drops of concentrated hydrochloric `

acid have been added 150 parts by weight o~ ethyl vinyl ether is o~z~ 29J481~ .
10366~Z
dripped in while stirring. The internal temperature is prevented from rising above 65C by external cooling with ice. A11 of the pyrocatechol has dissolved upon completion of the reaction. 5 parts by weight of 2-normal caustic soda solution is added, the whole is allowed to cool~ and dried over sodium sulfate, the solvent is removed and the product is distilled in vacuo. The ` yield is almost quantitative; boiling point 78 to 81C at 1 mm;
i nD25= 1.5032 Analysis: C1oH1403 (182) ; 10 calculated: C 66.o H 7.7 found: C 66.3 H 7.9 -(b) Pyrocatechol-bis- [(1-ethoxy)-ethyl~-ether:

The method of (a) is employed, except that 300 parts by weight of ethyl vinyl ether is used instead of 150 parts by weight. 248 parts by weight of a colorless oil is obtained having a boiling ~, polnt of 97 to 102C at 0.3 mm.
Analysis: C14H2204 (254) calculated: C 66.2 H 8.6 found: C 66.4 H 8.7. ;-(c) o-(1-ethox~ethox~)-phenol:
127 parts by weight of pyrocatechol- [(1-ethoxy)-ethyl]-ether and 55 parts by weight of pyrocatechol are reacted and processed as described in Example 3(c). The yield is 179 parts of the phenol compound, The boiling point is 79 to 80C at 1 mm.

o-(methoxymethox~)-phenol:
110 parts by weight of pyrocatechol is dissolved in 400 parts -by weight of benzene. 101 parts by weight of triethylamine and , ~: ' ' :

... . . ., . - . - - . - ~
. - . . ,, . ., ~
: - ~ :: - , - : -.

` ` O.Z. 29,484 81 parts by weight of chloromethyl methyl ether are dripped in simultaneously at ambient temperature in such a manner that the reaction medium has a weakly basic reaction. The whole is then heated for another hour under re~lux; it is allowed to cool and the hydrochloride is suction filtered, washed with water, dried over sodium sulfate, concentrated and distilled in vacuo.
The yield is 120 parts by weight and the boiling point is 89C at ,,~
0.4 mm; nD'= 1.5150.

Analysis: CgHloO3 (154) 10 calculated: C 62.~ H 6.5 .

found: C 62.0 H 6.5 ~. :

-14- . :

Claims (15)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for the production of a pyrocatechol ether of the formula where R1 is hydrogen or lower alkyl; R2 is lower alkyl, lower alkyl substituted by halogen, methoxy, ethoxy, or benzyl; R3 is phenyl, lower alkyl, cycloalkyl, .beta.-chloroethyl, alkoxyalkyl, lower alkenyl, lower alkynyl or acyl; R1 and R2 together with the carbon atom whose substituents they are and R1 and R3 together with the carbon or oxygen atom whose substituents they are denote a five-membered or six-membered ring, wherein pyrocatechol is reacted, in the presence of a catalytic amount of a substance having an acid action, with a vinyl ether of the formula ROR3, where R is vinyl or vinyl bearing lower alkyl and R3 has the above meanings, or, in the presence of an organic or inorganic base, with an .alpha.-haloether of the formula:

where Hal is Cl, Br or I and R1, R2 and R3 have the above meanings.

2. Process as claimed in claim 1, wherein the bisether obtained and having the formula:

in which R1, R2 and R3 have the meanings given in claim 1 is reacted with pyrocatechol.

3. Process as claimed in claim 1, characterized in that pyrocatechol is reacted, in the presence of a catalytic amount of a substance having an acid action, with vinyl methyl ether to obtain O-(1-methoxyethoxy)-phenol.

4. Process as claimed in claim 1, characterized in that pyrocatechol is reacted with twice the molar amount of vinyl methyl ether to obtain pyrocatechol-bis-[(1-methoxy)-ethyl]-ether.

5. Process as claimed in claim 4, wherein pyrocatechol-bis-[(1-methoxy)-ethyl]-ether obtained is reacted with pyrocate-chol to obtain O-(1-methoxyethoxy)-phenol.

6. Process as claimed in claim 1, characterized in that pyrocatechol is reacted, in the presence of a catalytic amount of a substance having an acid action, with ethyl vinyl ether to obtain O-(1-ethoxyethoxy)-phenol.

7. Process as claimed in claim 1, characterized in that pyrocatechol is reacted with twice the molar amount of ethyl vinyl ether to obtain pyrocatechol-bis-[(1-ethoxy)-ethyl]- ether.

8. Process as claimed in claim 7, wherein pyrocatechol-bis-[(1-ethoxy)-ethyl]-ether is reacted with pyrocatechol to obtain O-(1-ethoxyethoxy)-phenol.

9. Process as claimed in claim 1, characterized in that pyrocatechol is reacted, in the presence of a base, with chlorome-thyl methyl ether to obtain O-(methoxymethoxy)-phenol.

10. Process as claimed in claim 1, characterized in that pyrocatechol is reacted, in the presence of a base, with chlorome-thyl isopropyl ether to obtain O-(2-methoxy-isopropoxy)-phenol.

11. A pyrocatechol ether of the formula:

where R1 is hydrogen or lower alkyl; R2 is lower alkyl, lower alkyl substituted by halogen, methoxy, ethoxy, or benzyl; R3 is phenyl, lower alkyl, cycloalkyl, .beta.-chloroethyl, alkoxyalkyl, lower alke-nyl, lower alkynyl or acyl; R1 and R2 together with the carbon atom whose substituents they are and R1 and R3 together with the carbon or oxygen atom whose substituents they are denote a five-membered or six-membered ring, whenever obtained by a process as claimed in claims 1 or 2 or its obvious chemical equivalents.

12. O-(1-methoxyethoxy)-phenol whenever obtained by a process as claimed in claims 3 or 5 or its obvious chemical equivalents.

13. O-(1-ethoxyethoxy)-phenol whenever obtained by a process as claimed in claims 6 or 8 or its obvious chemical equivalents.

14. O-methoxymethoxyphenol whenever obtained by a process as claimed in claim 9 or its obvious chemical equivalents.

15. O-(2-methoxyisopropoxy)-phenol whenever obtained by a process as claimed in claim 10 or its obvious chemical equivalents.