IE56260B1 - Process for the preparation of 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran - Google Patents
Process for the preparation of 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuranInfo
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- IE56260B1 IE56260B1 IE2690/83A IE269083A IE56260B1 IE 56260 B1 IE56260 B1 IE 56260B1 IE 2690/83 A IE2690/83 A IE 2690/83A IE 269083 A IE269083 A IE 269083A IE 56260 B1 IE56260 B1 IE 56260B1
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
- C07D307/77—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom ortho- or peri-condensed with carbocyclic rings or ring systems
- C07D307/78—Benzo [b] furans; Hydrogenated benzo [b] furans
- C07D307/86—Benzo [b] furans; Hydrogenated benzo [b] furans with an oxygen atom directly attached in position 7
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/01—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by replacing functional groups bound to a six-membered aromatic ring by hydroxy groups, e.g. by hydrolysis
- C07C37/055—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by replacing functional groups bound to a six-membered aromatic ring by hydroxy groups, e.g. by hydrolysis the substituted group being bound to oxygen, e.g. ether group
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- Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
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Abstract
For the Contracting States : AT, BE, CH, GB, LI, LU, NL, SE 1. A process for the preparation of 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran from ortho-methallyloxyphenol by heating, by rearrangement or the ortho-methallyloxyphenol and then cyclisation of the rearranged compound thus obtained, wherein at least the cyclisation step is carried out by heating in the presence of an effective amount of a catalyst consisting of a tin derivative. For the Contracting States : DE, FR, IT 1. A process for the preparation of 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran from ortho-methallyloxyphenol by heating, by rearrangement or the ortho-methallyloxyphenol and then cyclisation of the rearranged compound thus obtained, wherein at least the cyclisation step is carried out by heating in the presence of an effective amount of a catalyst consisting of a tin derivative which is not SnCI4 .
Description
PROCESS FOR THE PREPARATION OF 2,3-DIHYDRO-2t2-DIMETHYL 7-HYDROXYBENZOFURAN The invention relates to a process for the preparation of 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran from ortho-methallyloxyphenol* 2,3-Dihydro-2,2-dimethyl-7-hydroxybenzofuran, hereafter denoted by DDHB, has the formula: OH CH.
CH.
This compound, which is in itself known, can be used for the preparation of 2,3-dihydro-2,2dimethylbenzofuran-7-yl methylcarbamate, which is a multi-purpose insecticide known by the name of carbofuran.
Ortho-methallyloxyphenol, or 2-methallyloxyphenol, is the compound of the formulas O-CH -C-CH 2 3 CHII It is knownto prepare DDHB from ortho15 methallyloxyphenol by rearrangement of this compound (ortho transposition of the methallyl radical), forming a rearranged compound (in particular orthomethallylpyrocatechol) as an intermediate, and then cyclisation of this rearranged compound to give DDHB.
Ortho-methallylpyrocatechol, or 1,2-dihydroxy-3methallylbenzene,is the compound of the formulas The manner in which this conversion of orthomethallyloxyphenol to DDHB is carried out, by rearrangement/ cyclisation, has formed the subject of several patent applications, leading to substantially different results according to the conditions used: - French Patent No.1403952, describes this conversion as being carried out by heating orthomethallyloxyphenol in bulk to 190°C, the temperature reaching 270°C during the conversion. According to the experiment described in the said patent, the yield is only 48.2%.
- European Patent Application No. 79 420062.6 (Publication No. 0 012 096) describes this conversion as being carried out by heating ortho-mdthallyloxyphenol to a temperature of about 200°C, in the presence of water and, optionally, of an inert organic solvent- The yields obtained are of the order of 69 to 72%.
- European Patent Application No. 80 420130.9 (Publication No- 0 030 511) describes this conversion as being carried out by heating ortho-methallyloxyphenol to temperatures generally of the order of 120 to 150°C, in the presence of an aluminium derivative, preferably aluminium isopropylate, as a catalyst and, optionally, in the presence of an organic solvent. The yields obtained vary from about 60 to 77%. Example 9 of the said European Patent Application shows that if the reaction is carried out at a lower temperature (100°C), a substantially lower yield of DDHB is obtained (60.7%) despite the use of larger amounts of catalyst (0.3 mol of catalyst per mol of ortho-methallyloxyphenol).
- European Patent Application No. 80 104521.2 (Publication No. 0 025 843) describes this conversion as being carried out by heating ortho-methallyloxyphenol to temperatures of about 150 to 190°C, in a solvent consisting of a polyhydroxyalkyl ether containing at least one OH group, in the presence of p-toluenesulphonic acid or ferric chloride as a catalyst. According to the examples described, the yields vary from 65 to 70%.
However, none of the processes described in these references proved totally satisfactory.
The object of the invention is to provide an improved process for the preparation of DDHB using different catalysts from those described or suggested in the abovementioned patents or patent applications* More precisely, the object of the present invention is to provide a process for the preparation of DDHB from ortho-methallyloxyphenol which makes it possible to obtain good yields of DDHB while carrying out the reaction at a substantially lower temperature than in the processes described in the abovementioned patents or patent applications.
It has now been found that this object can be achieved by virtue of a new process forming the subject of the present invention.
This process relates to the preparation of DDHB from ortho-methallyloxyphenol by heating, the said process comprising rearrangement of the ortho-methallyloxyphenol and then cyclisation of the rearranged compound. In the process, at least the cyclisation step is carried out by heating in the presence of an effective amount of a catalyst consisting of a tin derivative.
In a first embodiment of the invention, the ortho-methallyloxyphenol is first heated to a high temperature in the absence of tin derivative by which, depending on the conditions used, the starting compound is partially or totally converted to the rearranged compound (in particular ortho-methallylpyrocatechol). The reaction mixture thus obtained is then heated in the presence of the tin derivative so as to effect the cyclisation of the rearranged derivative.
In this first embodiment of the invention, the rearrangement step and the cyclisation step can be carried - 5 out in two totally separate operations: thus, the orthomethallyloxyphenol can be heated so as to cause its rearrangement, e.g. by operating under the conditions described in European Patent Application No. 80 420130.9 (page 9, comparative experiment), and hence to obtain a mixture containing mainly ortho-methallylpyrocatechol, and then, in a second operation separate from the first, this reaction mixture can be heated in the presence of a tin derivative. In a variant of this first embodiment of the invention, the rearrangement and the cyclisation can also be carried out successively in the same apparatus, heating being carried out first in the absence of tin derivative and subsequently continued in the presence of a tin derivative, which is then added to the reaction mixture.
In a preferred embodiment of the invention, the rearrangement of the ortho-methallyloxyphenol is carried out by heating this compound in the presence of a tin derivative, and the cyclisation of the rearranged compound is also carried out by heating in the presence of a tin derivative. In this preferred embodiment of the invention, it is particularly advantageous to heat the orthomethallyloxyphenol in the presence of the tin derivative and to continue this heating, in the presence of the same tin derivative, until the DDHB is formed. Under these conditions, it is observed that the second conversion immediately follows the first. This is therefore a process - 6 which makes it possible to produce DDHB from orthomethallyloxyphenol in a single step. In this process, the ortho-methallyloxyphenol is heated in the presence of a tin derivative. This constitutes the preferred embodiment of the invention.
For the purpose of the present description and claims the term tin derivative is to be understood as meaning organic or inorganic derivatives of divalent tin or tetravalent tin and any tin-based reagent capable of forming a divalent tin or tetravalent tin derivative in situ, under the reaction conditions.
These divalent tin and tetravalent tin derivatives correspond to the general formula: Sn(R)ffl IV in which R represents an atom, e.g. a halogen, oxygen or sulphur atom or an inorganic or organic group, and m represents an integer equal to 2 or 4, it being understood that the substituents R can be either identical or different R is advantageously chosen from amongst the substituents mentioned belows - halogen atoms (preferably chlorine), - alkyl radicals (e.g. ethyl, methyl and butyl radicals) or cycloalkyl radicals which are optionally substituted (e.g. by one or more halogens), - aryl or alkaryl radicals (e.g. the phenyl radical) which are optionally substituted, and - the radicals -OR^, in which represents an organic radical such as. for example, an alkyl, aryl or acyl radical or the benzofuryl radical, it being possible for these radicals to be optionally substituted (e.g. the 2,3-dihydro-2,2-dimethylbenzofuran-7-yl radical, the ortho-methallyloxyphenol radical or hydroxy(methallyl)phenyl radicals, it being possible, if appropriate, for these various radicals to be formed in situ)Thus, if R represents the radical -0R1( this substituent R can denote, inter alia, the phenoxy radical or the acetoxy radical (CH^COO-)Amongst the compounds corresponding to the above formula IV, compounds such as SnC^i tin methylate, SnCl^, tin diacetate, dibutyltin diacetate and dichlorodibutyltin can advantageously be used, but this list does not imply a limitation.
Preferably, the tin derivatives used are divalent tin derivatives, i.e. compounds corresponding to general formula IV indicated above in which m is 2, R having the same meaning as above.
Stannous chloride (SnCU^) is very particularly preferred amongst these preferred compounds, because it makes it possible to obtain high yields above a temperature of 100°C, as shown by the Examples described hereafter.
The amount of tin derivative to be used must be sufficient to enable the conversion to proceed satisfactorily under the conditions used- This is generally achieved by using at least 0.00005 mol of tin derivative per mol of compound to be converted (ortho-methallyloxyphenol or the derivative from rearrangement of this compound). The upper limit to the amount of catalyst is not critical. In practice, it is advantageous to use from 0.0001 to 0.3 mol of tin derivative per mol of compound to be converted, and preferably from 0-005 to 0.1 mol of tin derivative per mol of compound to be converted.
The temperature at which heating is carried out in the presence of the tin derivative can be between 60°C and 200°C and it is preferably between 80°C and 130°CIf the tin derivative used as the catalyst is stannous chloride, very advantageous results are obtained by carrying out the reaction above a temperature of 100°C.
The conversion according to the invention can be carried out by heating the ortho-methallyloxyphenol, and/or its rearrangement product, in bulk, in the absence of solvent.
Preferably, however, this conversion is carried out in an organic solvent advantageously chosen from amongst aromatic hydrocarbons such as toluene and ο-, m- and p-xylenes? aliphatic hydrocarbons such as octane or decane? chlorinated aromatic hydrocarbons? cycloaliphatic hydrocarbons such as cyclohexane? aliphatic or aromatic ethers such as anisole; ketones such as methyl isobutyl ketone; alcohols such as lower alkanols, e.g. isopropanol; phenols and more particularly phenol itself; and polyhydroxyalkyl ethers (such as those mentioned in European Patent Application No. 80 104521.2), but this list does not imply a limitation.
The conversion according to the invention is advantageously carried out under ordinary atmospheric pressure. However, it can be carried out under a pressure other than ordinary atmospheric pressure. Thus, if it is desired to use a solvent whose boiling point under normal atmospheric pressure is below the temperature at which it is desired to carry out the reaction, the conversion according to the invention can be carried out in an autoclave under a pressure greater than atmospheric pressureThe time required to effect the conversion according to the invention depends on the temperature used and also on other factors such as the choice of catalyst, but the conversion time is generally the shorter, the higher the temperature. The conversion time is generally between 15 minutes and twenty hours.
At the end of the reaction, the DDHB obtained is separated off by any means known per se such as, for example, by distillation. However, for certain uses, it may not be necessary to isolate the DDHB, in which case it suffices to leave it in the reaction medium, which is itself used in the desired manner. The tin derivative can be removed by - 10 washing the reaction mixture with an aqueous solution of a strong acid.
The Examples which follow, which are described without implying a limitation, illustrate the invention and show how it can be implementedHereafter, DC(ME) will be used systematically to denote the degree of conversion of the ortho-methallyloxyphenol, evaluated from the amount of this compound present in the reaction medium at the beginning and end of the operation respectively, and Y(DDHB) will be used systematically to denote the yield of 2,3-dihydro-2,2-dimethyl~7hydroxybenzofuran (or DDHB), calculated from the orthomethallyloxyphenol converted.
Example 1 The apparatus used consists of a 100 ml roundbottomed flask fitted with a reflux condenser and a magnetic stirring barThe following are charged successively into this flask: - ortho-methallyloxyphenol (1.0294 g: 6.28x10 mol) - stannous chloride (0.052 g; 2=74x10"^ mol) - methyl isobutyl ketone (50 ml).
This mixture is heated for 16 hours 30 minutes at 100°C, with stirring, and then cooled to ambient temperature (25°C). 2N HCl (20 ml) is then added, followed by ethyl acetate (20 ml), and the whole is shaken in a separating funnel.
After the organic phase and the aqueous phase have been separated, the organic phase is washed with distilled water (30 ml), which is then combined with the aqueous phase- This aqueous phase is in turn washed with ethyl acetate (20 ml), which is combined with the first organic phase- The volume of the organic phase is then adjusted to 100 ml and the solution obtained is analysed by liquid phase chromatographyThe following are determined in the solution: - unconverted ortho-methallyloxyphenol (0-0224 g; 1.36x10"^ mol) - DDHB (0.793 g: 4-83xl0-3 mo1) - ortho-methallylpyrocatechol (0.0017 g; 1x10 mol).
The results are as follows: - DC(ME) = 98 % - Y(DDHB) = 78-7 %.
Example 2 The same method as in Example 1 is followed, using the same tin derivative (SnCl^) and the same solvent as in Example 1, and starting from: _2 - ortho-methallyloxyphenol (1-9421 g; 1.184x10 mol) - stannous chloride (0-1121 g; 5.91x10^ mol) - methyl isobutyl ketone (35 ml) and heating at 105°C, as in Example No. 1, but for a period of 9 hours 30 minutes. - 12 The results are as follows: - DC(ME) = 100 % - Y(DDHB) = 79 %.
Example 3 The same method as in Example 1 is followed, using the same tin derivative and the same solvent as in Example 1 and starting from: - ortho-methallyloxyphenol (2.040 g? 12.44x10^ mol) - stannous chloride (0.101 g; 5,3x10"^ mol) - methyl isobutyl ketone (18 ml).
Heating is carried out at 105°C for 6 hours, with stirring, under an inert atmosphere.
The results are as follows: - DC(ME) = 87.7 % -Y(DDHB) = 79.3 %Example 4 The same method as in Example 1 is followed, using the same tin derivative as in Example 1, but replacing the methyl isobutyl ketone by isopropanol and carrying out the reaction in an autoclave under an inert atmosphere.
The experiment is carried out starting from: - ortho-methallyloxyphenol (1.619 g; 9,87xl0~3 mol) □ - stannous chloride (0.0891 g? 0.470x10 mol) - isopropanol (12 ml).
The mixture is heated at 100°C for 16 hours.
The results are as follows: —DC(ME) - 54*3 % - Y(DDHB) = 79.6 %.
Example 5 The same method as in Example 1 is followed, using the same tin derivative as in Example 1, but heating the ortho-methallyloxyphenol in bulk without using a solvent.
The experiment is carried out starting from: - ortho-methallyloxyphenol (1.4727 g; 8.98x10*^ mol) _5 - stannous chloride (0*0150 g; 7.9x10 mol).
Heating is carried out at 100°C for 7 hours 30 minutes.
The results are as follows: - DC(ME) = 100 % - Y(DDHB) = 53%.
Example 6 The same method as in Example 1 is followed, but using tin acetate, of the formula: (CH3C00,2Sn as the catalyst and carrying out the reaction in m-xylene as the solvent.
The experiment is carried out starting from: - ortho-methallyloxyphenol (1.6456 g; 10.03x10 mol) - tin acetate (0.0487 g; 0.206x10’mol) - m-xylene (11 ml). - 14 Heating is carried out at 120°C for 16 hours, under an inert atmosphere.
The results are as follows: - DC(ME) 86.6% - Y(DDHB) = 67.3%.
Example 7 The same method as in Example 1 is followed, but using tin methylate, of the formula: (CH3O)2Sn as the catalyst and heating the ortho-methallyloxyphenol in bulk without using a solvent.
The experiment is carried out starting from: - ortho-methallyloxyphenol (2.2740 g: 13-86x10 mol) - tin methylate (0.0273 g; 0&15xl0~^ mol).
Heating is carried out at 97°C for 14 hours, under an inert atmosphere, with stirring.
The results are as follows: - DC(ME) - 63.5% - Y(DDHB) = 61.7%.
The tin methylate was prepared by the method described by J.S. Morrison and H.M. Haendler in J-Inorg. Nucl.Chem. 29, 395 (1967).
Example 8 The same method as in Example 1 is followed, but using dibutyltin diacetate, of the formula: (CH3C00)2Sn(C4H9)2 as the catalyst and heating in bulk without using a solvent The experiment is carried out starting from: - ortho-methallyloxyphenol (1.720 g; 10-49x10 mol) - dibutyltin diacetate (0-0368 g; 0-105x10 mol).
Heating is carried out at 95°C for 15 hours 30 minutes, under an inert atmosphere, with stirring.
The results are as follows: - DC (ME) = 56 % - Y(DDHB) = 50 %.
Example 9 The same method as in Example 1 is followed, but using dichlorodibutyltin, of the formula: (Cl)2Sn(C4H9)2 as the catalyst and heating in bulk without using a solvent.
The experiment is carried out starting from: —3 - ortho-methallyloxyphenol (2-020 g; 12-19x10 mol) - dichlorodibutyltin (0.036 g: 0.118x10 mol).
Heating is carried out at 120°C for 6 hours.
The results are as follows: - DC(ME) = 67.5% - Y(DDHB) = 55.5% Example 10 The same method as in Example 1 is followed, but using stannic chloride, of the formula: SnCl^ - 16 as the catalyst and carrying out the reaction, as in Example 1, in methyl isobutyl ketone.
The experiment is carried out starting from: „3 - ortho-methallyloxyphenol (2.020 g? 12.32x10 mol) —3 - stannic chloride (0.147 g: 0.56x10 mol) - methyl isobutyl ketone (18 ml).
Heating is carried out at 105°C for 6 hours, with stirring and in an inert atmosphere.
The results are as follows: - DC(ME) = 99% - Y(DDHB) = 48% Example 11 A tube fitted with a stirrer and placed under an inert atmosphere is used.
A product (0.1336 g, containing 80% by weight of _3 ortho-methallylpyrocatechol (0.652x10 mol) and dibutyltin diacetate (0-0043 g? 0.012x10*3 mol) are placed in this tube Heating is carried out for 3 hours 30 minutes at 130°C.
It is then observed that all the orthomethallylpyrocatechol has disappeared from the reaction mixture, and DDHB (0.109 g) is thus obtained, i.e. a yield of DDHB equal to 100%, calculated relative to the starting ortho-methallylpyrocatechol.
The starting product containing orthomethallylpyrocatechol was obtained from ortho17 methallyloxyphenol by heating at 200°C for 1 hour minutes, in cyclohexane.
Experiment A In the same apparatus as in Example 1, the ortho-methallyloxyphenol was heated in bulk without using a solvent, and in the absence of tin derivative, to a temperature of 112°C, and this heating was continued at this temperature for 24 hours.
The results are as follows: - DC (ME) = 43% - Y(DDHB) = 0%.
Analysis of the reaction mixture shows that it contains mainly ortho-methallylpyrocatechol (uncyclised) and a smaller proportion of para-methallylpyrocatechol (or 1,2-dihydroxy-4-methallylbenzene), these proportions being respectively 62.3% and 20.2%, relative to the ortho-methallyloxyphenol converted.
Experiment B Experiment A is repeated, the orthomethallyloxyphenol being heated in bulk, in the absence of tin derivative, but this heating being carried out at 130°C for 15 hours.
The results are as follows: - DC (ME) = 82 % - Y(DDHB) = 1.4% Analysis of the reaction mixture shows that it contains mainly ortho-methallylpyrocatechol (uncyclised) - 18 and a smaller proportion of para-methallylpyrocatechol, these proportions being respectively 61% and 22%, relative to the ortho-methallyloxyphenol converted.
• Experiment C Experiment A is repeated, the orthot methallyloxyphenol being heated in the absence of tin derivative, except that the ortho-methallyloxyphenol is heated at l40°C for 11 hours in an organic solvent (para-xylene).
The results are as follows: - DC (ME) = 98.2% - Y(DDHB) = 1-8%.
Analysis of the reaction mixture shows that it contains mainly ortho-methallylpyrocatechol (uncyclised) and a smaller proportion of para-methallylpyrocatechol.
These experiments A, B and C show that, in the absence of tin derivative, virtually no DDHB is formed for temperatures ranging from 112°C to l40°C, since the Y(DDHB) is between 0% and 1.8% under these conditions20 Experiment C also shows that the rearrangement of the ortho-methallyloxyphenol can be carried out satisfactorily (DC(ME) = 98.2%) in the absence of catalyst, provided that heating is carried out at a higher temperature (14O°C).
The experiments described in Examples 1 to 11 show that, under very similar temperature conditions, and in certain cases at lower temperatures, the presence of a tin derivative in the reaction mixture enables the cyclisation to proceed satisfactorily, since the Y(DDHB) varies from 48% (Example 10) to 79-6% (Example 4) under these conditions. * A comparison of the results obtained with divalent tin derivatives, described in Examples Nos. 1 to 7, with ' those obtained with tetravalent tin derivatives, described in Examples Nos- 8 to 10, shows that the divalent tin derivatives lead to Y(DDHB) values which are generally substantially higher than the Y(DDHB) values obtained with the tetravalent tin derivativesFinally, a comparison of the result obtained with SnCl2 in Example 3 (Y(DDHB) = 79-3%) with that obtained with SnCl^ in Example 10 (Y(DDHB) = 48%), using exactly the same conditions as in Example 3, demonstrates that SnCl2 is distinctly superior to SnCl^ in the conversion of orthomethallyloxyphenol to DDHB.
Furthermore, on referring to Examples Nos- 1 and 2, it will be observed that the use of SnCl2 as the catalyst makes it possible, above a temperature of 100°C, to obtain both a high degree of conversion of the orthomethallyloxyphenol [DC(ME) of 98% to 100%] and a high Y(DDHB) (78-7% to 79%), i-e- results which are substantially equivalent to the best results obtained at considerably * higher temperatures in the Examples described in European fyd-if'.· ,ρ-1Patent Applications Nos 012096'and 0 030511 heretofore mentioned.
Claims (18)
1. A process for the preparation of 2,3dihydro-2,2-dimethyl-7-hydroxyben2ofuran from orthomethallyloxyphenol by heating, by rearrangement of the ortho-methallyloxyphenol and then cyclisation of the rearranged compound thus obtained, wherein at least the cyclisation step is carried out by heating in the presence of an effective amount of a catalyst consisting of a tin derivative.
2. A process according to claim 1 wherein the rearrangement of the ortho-methallyloxyphenol is carried out by heating in the absence of tin derivative, and wherein the cyclisation of the rearranged compound is then carried out by heating this compound in the presence of a catalyst consisting of a tin derivative.
3. « A process according to claim 1 or 2 wherein the rearranged compound which is subjected to cyclisation is ortho- methallylpyrocatechol.
4. A process according to claim 1, wherein the rearrangement of the ortho-methallyloxyphenol is carried out by heating in the presence of a tin derivative, and wherein the cyclisation of the rearranged compound is then carried out by heating in the presence of a tin derivative
5. A process according to claim 4 wherein the ortho-methallyloxyphenol is heated in the presence of a tin derivative until 2,3-dihydro-2,2-dimethyl-7hydroxybenzofuran is obtained*
6. A process according to any one of claims 1 to 5 wherein the tin derivative is a compound of the formulas Sn(R) m m in which R represents a halogen atoaa or an inorganic or organic group and m is equal to 2 or 4, it being understood that the substituents R can be either identical or different, or a tin-based reagent capable of forming such a compound in situ under the reaction conditions.
7. A process according to claim 6 in which R represents a halogen atom, an optionally substituted alkyl radical, an optionally substituted aryl radical, an optionally substituted alkaryl radical or the radical -ORj wherein represents an organic radical.
8. A process according to claim 6 or 7 wherein m is equal to 2.
9. A process according to any one of claims 1 to 8 wherein the tin derivative used as the catalyst is stannous chloride.
10. A process according to any one of claims 1 to 9 wherein at least 0-00005 mol of tin derivative is used per mol of compound to be converted.
11. - A process according to any one of claims 1 to 9 wherein from 0.0001 to 0.3 mol of tin derivative is used per mol of compound to be converted.
12. A process according to any one of claims 1 to 9 wherein from 0.005 to 0.1 mol of tin derivative is used per mol of compound to be converted.
13. A process according to any one of claims 1 to < 12 wherein heating in the presence of the tin derivative is carried out at a temperature of between 60°C and 200°C e ' Λ
14. A process according to any one of claims 1 to 12 wherein heating in the presence of the tin derivative is carried out at a temperature of between 80°C and 130°C.
15. A process according to any one of claims 1 to 14 wherein the reaction is carried out in an organic solvent.
16. A process according to claim 15 wherein the organic solvent is an aromatic hydrocarbon, an aliphatic hydrocarbon, a chlorinated aromatic hydrocarbon, a cycloaliphatic hydrocarbon, an aliphatic or aromatic ether, a kerone, an alcohol, a phenol or a polyhydroxyalkyl ether
17. A process according to any one of claims 1 to 16 wherein the reaction is carried out under ordinary atmospheric pressure
18. A process according to any one of claims 1 to 17 substantially as herein described with especial reference to Examples 1 to 1119- 2,3-Dihydro-2,3-dimethyl-7-hydroxybenzofuran whenever prepared by a process claimed in any one of claims 1 to J 8. - 24 20. A process substantially as hereinbefore described with reference to the Examples.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8219548A FR2536395A1 (en) | 1982-11-18 | 1982-11-18 | PROCESS FOR THE PREPARATION OF 2,3-DIHYDRO-2,2-DIMETHYL-7-HYDROXY BENZOFURAN |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| IE832690L IE832690L (en) | 1984-05-17 |
| IE56260B1 true IE56260B1 (en) | 1991-06-05 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| IE2690/83A IE56260B1 (en) | 1982-11-18 | 1983-11-17 | Process for the preparation of 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran |
Country Status (19)
| Country | Link |
|---|---|
| EP (1) | EP0112785B1 (en) |
| JP (1) | JPS59106481A (en) |
| KR (1) | KR910002542B1 (en) |
| AT (1) | ATE37181T1 (en) |
| BG (1) | BG42006A3 (en) |
| BR (1) | BR8306229A (en) |
| DD (1) | DD212514A5 (en) |
| DE (1) | DE3377987D1 (en) |
| DK (1) | DK163430C (en) |
| ES (1) | ES8406462A1 (en) |
| FR (1) | FR2536395A1 (en) |
| HU (1) | HU194201B (en) |
| IE (1) | IE56260B1 (en) |
| IL (1) | IL70107A (en) |
| PL (1) | PL145981B1 (en) |
| PT (1) | PT77679B (en) |
| RO (1) | RO87595B (en) |
| SU (1) | SU1331428A3 (en) |
| YU (1) | YU42631B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1199987B (en) * | 1983-02-04 | 1989-01-05 | Brichima Spa | PROCESS FOR THE PRODUCTION OF BENZOFURANIC DERIVATIVES |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2932458A1 (en) * | 1979-08-10 | 1981-02-26 | Bayer Ag | PRODUCTION OF MONOALKYL ETHERS FROM HYDROXYPHENOLS AND THEIR CONVERSION TO HYDROXYCUMARANES |
| FR2470768A1 (en) * | 1979-12-07 | 1981-06-12 | Rhone Poulenc Agrochimie | PROCESS FOR THE PREPARATION OF BENZOFURAN DERIVATIVES |
| US4380654A (en) * | 1982-02-18 | 1983-04-19 | Fmc Corporation | Process for preparation of 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran |
-
1982
- 1982-11-18 FR FR8219548A patent/FR2536395A1/en active Granted
-
1983
- 1983-11-01 IL IL70107A patent/IL70107A/en not_active IP Right Cessation
- 1983-11-08 KR KR1019830005287A patent/KR910002542B1/en not_active IP Right Cessation
- 1983-11-11 BR BR8306229A patent/BR8306229A/en not_active IP Right Cessation
- 1983-11-14 EP EP83420173A patent/EP0112785B1/en not_active Expired
- 1983-11-14 DE DE8383420173T patent/DE3377987D1/en not_active Expired
- 1983-11-14 AT AT83420173T patent/ATE37181T1/en active
- 1983-11-16 PT PT77679A patent/PT77679B/en not_active IP Right Cessation
- 1983-11-16 JP JP58215865A patent/JPS59106481A/en active Granted
- 1983-11-16 YU YU2253/83A patent/YU42631B/en unknown
- 1983-11-16 BG BG8363086A patent/BG42006A3/en unknown
- 1983-11-16 PL PL1983244580A patent/PL145981B1/en unknown
- 1983-11-17 DD DD83256814A patent/DD212514A5/en not_active IP Right Cessation
- 1983-11-17 IE IE2690/83A patent/IE56260B1/en not_active IP Right Cessation
- 1983-11-17 HU HU833967A patent/HU194201B/en not_active IP Right Cessation
- 1983-11-17 ES ES527341A patent/ES8406462A1/en not_active Expired
- 1983-11-17 DK DK527083A patent/DK163430C/en not_active IP Right Cessation
- 1983-11-17 SU SU833663190A patent/SU1331428A3/en active
- 1983-11-17 RO RO112585A patent/RO87595B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| ATE37181T1 (en) | 1988-09-15 |
| JPH0513951B2 (en) | 1993-02-23 |
| SU1331428A3 (en) | 1987-08-15 |
| RO87595A (en) | 1985-08-31 |
| EP0112785B1 (en) | 1988-09-14 |
| PT77679A (en) | 1983-12-01 |
| JPS59106481A (en) | 1984-06-20 |
| KR840006640A (en) | 1984-12-01 |
| DK527083A (en) | 1984-05-19 |
| YU42631B (en) | 1988-10-31 |
| DE3377987D1 (en) | 1988-10-20 |
| KR910002542B1 (en) | 1991-04-23 |
| BG42006A3 (en) | 1987-09-15 |
| DK527083D0 (en) | 1983-11-17 |
| PT77679B (en) | 1986-05-12 |
| YU225383A (en) | 1986-02-28 |
| IL70107A0 (en) | 1984-02-29 |
| BR8306229A (en) | 1984-06-19 |
| IE832690L (en) | 1984-05-17 |
| FR2536395B1 (en) | 1985-03-29 |
| ES527341A0 (en) | 1984-08-01 |
| HU194201B (en) | 1988-01-28 |
| PL145981B1 (en) | 1988-12-31 |
| EP0112785A1 (en) | 1984-07-04 |
| RO87595B (en) | 1985-08-31 |
| DK163430B (en) | 1992-03-02 |
| DD212514A5 (en) | 1984-08-15 |
| DK163430C (en) | 1992-07-20 |
| IL70107A (en) | 1987-03-31 |
| ES8406462A1 (en) | 1984-08-01 |
| FR2536395A1 (en) | 1984-05-25 |
| PL244580A1 (en) | 1984-09-24 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MM4A | Patent lapsed |