DE2210108B2 - PROCESS FOR CONDUCTING SENSITIZED PHOTOREACTIONS AND THE USE OF INOLUBLE SENSITIVIZERS FOR CONDUCTING SENSITIZED PHOTOREACTIONS - Google Patents

Description

Acetophenone, propiophenone, / S-chloropropiophenone The reactions are preferred in the case of space or benzophenone sulfonic or carboxylic acids; Salts carried out temperature, but the temperature of aromatic monocarboxylic acids, e.g. B. the potassium can be varied largely to the lowest possible salt of benzoic acid; To achieve salts of aromatic polycarbonate viscosity of the reaction medium. According to acids or the corresponding monoesters, such as 5 above, the temperature is only limited by the boiling point of the disodium salt of phthalic acid or the sodium salt of the solvent or of the starting material,
of terephthalic juiremonomethyl ester; Salts of high- In photoreactions with starting materials of type I, condensed aromatic carboxylic or sulfonic acids are precluded as far as possible from oxygen, e.g. B. Anthracensulfonsäuren, Pyrensulfon- added what can be achieved for example by introducing nitrogen acids, Benzpyrensulfonsäuren, Tetracencarbonsäuren io or noble gases. The oxygen etc .; Salts of mono- or polycyclic quinone content of the solution should advantageously IO- ³ to sulfonic or carboxylic acids, eg. B. 1.4-naphthoquinone do not exceed ^{10 ~ s volume percent,}
sulfonic acid, anthraquinone sulfonic acids, anthra- In the process according to the invention, the starting materials quinone-2,3-dicarboxylic acid, tetracene-SH-quinonsulfonic acid, liquid form or in solution in continuous fatty acids, 9,10-phenantrenquinone sulfonic acids, etc .; 15 Wise as often as you like on the stationary insoluble Rose Bengal; Metal complex salts passed by transition sensitizer. Preference is given to using the non-element (d-elements), in particular chromium (] II) -complete sensitizer in a thin layer, plex or cobalt (III) complex, such as chromium. The thickness and nature of the layer should be hexahurea or salts of symmetrical be that maximum absorption ratios for the or asymmetrical azo or azomethine-chromium 20 irradiated light are present and that optimal or cobalt complexes; in addition, polymers which contain conditions for the diffusion of the reactant molecules to form carbonyl or a thiocarbonyl group ensure the excited sensiusator molecules, with these carbonyl or thiocarbonyl groups being in front.

is conjugated to an aromatic system. Such sensitizer layers can e.g. B. so erBe examples of such polymers bind polyvinyl esters, 25 that the sensitizer is applied to a carrier as a powder or as polyvinyl acetate or polyvinyl propionate, in granules. With especially polyvinyl benzoate, polyalkyl esters, such as poly part, the insoluble sensitizer is drawn in a thin alkyl acetate, in particular polyalkyl benzoate, polyvinyl layer on a solid, translucent support on ketones, such as poly v ^; - >> lmethylketone, especially poly- or it is embedded in a thin, translucent carrier vinylarylketone, poly-N-vinylpyrrolidone .. polyacrylate 30 layer. The absorption of the insoluble sensitisers or polymethacrylates, also polyesters, polyamides, sators on translucent carrier can, for. B. after polyimides, polycarbonates, polyurethanes, polythio- customary processes by dusting, coating, aryl ketones, polyglycidyl compounds, z. B. those from spraying or dipping. Phthalic acid diglycidyl esters or terephthalic acid diglycidyl esters are particularly suitable as carrier materials and are particularly suitable in the corresponding irradiated phthalic acid or thiophthalic anhydrides, or 35 wavelength range permeable glass, and also polychalcones. Polyethylene, polypropylene or polycyclohexyl ether, copolymers of vinyl aryl ketones such. B. a polymer of the compounds of the formula
and vinylbenzene or especially divinylbenzene,

Copolymers of vinyl aryl ketones and methacrylic O * ~ "*

acid or acrylic acid esters, adducts from phthalic 40 ""
acid or terephthalic acid diglycidyl esters and

Phthalic or thiophthalic anhydrides, poly- O CH., ®

chalcones from 4,4'-diacetyldiphenyl ether or 4,4'-di- q
acetyldiphenylmethane and terephthaldianhydride, as well as linear polyesters, especially those made from aro-45
matic dicarboxylic acids and diols.

Polymers of the types mentioned can be used directly as a thin, advantageous, even if they are soluble per se, in the form of the reactant solution or the starting material liquid durchvon graft polymer to insoluble substrates ^f s mono- Roemte powder or granular layer with The sensitizer may be set. 50 den. However, it has proven to be particularly advantageous to use a polymer-speaking suitable solvent as an insoluble sensitizer. The solubility of such polymers in a film.

can be reduced by the introduction of salinizable The thickness of the polymeric sensitizer or the ionic groups, e.g. B. of sulfonic acid groups, sensitizer-containing layer is determined by Carboxylic acid groups, phosphoric acid groups or primary extinction coefficients and by the concentrations, secondary or tertiary amino groups. tration of the sensitizer used. The layer The light sources used for the implementation of the invention must at most be so thick that they are attached to the object in accordance with the invention Any sensitizer known to the surface of the educt solution can be used in the process, Molecules suitable for photochemical reactions are still stimulated by the light emitted by the EU Radiation sources in question. These can be within 60.

and / or attached outside of the reaction space. The diameter that is applied to a carrier and are chosen so that the emitted sensitizer layer or the layer thickness Light energy in the range of the absorption maximum in the case of polymeric sensitizers is therefore in general Sensitizer. The most common ones are mine, preferably smaller than 1 mm. In the case of carrier xenon lamps, High pressure and low mercury 65 sensitizers embedded in the material is the stratified pressure lamps, Tungsten lamps, halogen lamps, needle thickness are a function of those that can be achieved in the carrier material trium vapor lamps, as well as arc lamps. There can be sensitizer concentration. If the sensitizer one or more radiation sources can be used. directly than from the educt solution or from the liquid

Powder or granules through which the reactant flows form a copolymer of 95% acrylophenone and

is set, one preferably uses a layer thickness of 5% divinylbenzene is coated and that from the outside

up to 1 cm. Radially irradiated with three mercury lamps 125 watts

A possible execution of the procedure will exist. Samples are taken from the solution every hour.

z. B. in that you take a glass tube, which is taken through a 5 and analyzed by gas chromatography,

suitable light source is illuminated, with a reaction time of 6 hours, jl / ₀

Lining sensitizer polymer film. The to photo-trans-1,3-pentadiene before.

The reactant solution to be lysed is then continuously produced. The copolymer is prepared as follows: 30 g

pumped through the glass tube, and the resulting acrylophenone, 1.5 g divinylbenzene are in 200 ml

Photo products are dissolved by removing the benzene solution and degassed in a high vacuum. Under

by means of isolating * introduction of nitrogen, 200 mg of azo-isobutyr

Self verse .; The veronitrile according to the invention can finally be added. The reaction mixture is during

also not be carried out continuously. Stirred for 60 hours at 50 °, then to 10 1 Pe-

The inventive method has given to troläther and for a further 24 hours

previously known experimental arrangements, in particular the 15 stirred. The colorless precipitate of the formed

Advantage that the isolation of the photoproducts is very important, with polymers being isolated by decanting

is made easier, since the laborious separation of the Sensi petroleum ether (2 1) stirred up, filtered and dried

bilisators are not applicable. In addition, it is not necessary to use the Sensi- (50 ^c / 12 mm Hg).

to replace the bilizer on an ongoing basis. This means that approx. 0.5 g of the dried substance are required

requirements for a continuous photoreaction are met, so 10 ml of acetone are dissolved and poured into a 1 clinking, horizontal

In contrast to known processes, fleece also means stored glass tube. MiUeIs 2 IR lamps

considerable time and cost savings. The solvent is slowly evaporated. That

Turning thin layers has the advantage that the remaining polymer forms one on the larger

In contrast to working with powder or granulate glass surface, a well-adhering, transparent film,

suspensions the absorption cross-section is much greater than 25 The coated tube is at 70 to 80 ° / 12 mm Hg

and the light scattering is reduced. Since previously dried for 12 to 14 hours,
also in the case of sensitized photoreactions in solution

where one finds difficult or apparently insoluble sensi- Example 3
bilizers used, the solvents were always chosen so that the sensitizer concentration in 30 In 50 ml of cyclohexane are after degassing under the solution for a homogeneous sensitization from nitrogen, 68 mg of cis-1,3-pentadiene dissolved. This was, it is astonishing, and it was not possible to wait repeatedly through a glass tube that was passed through a glass tube according to the application (2.5 χ 20 cm), the inner surface of which was lined with an efficiency of energy transfer compared to polyester film . In these known test arrangements, the glass tube is also radially irradiated at 35 by means of three mercury lamps; purely heterogeneous sensitization is sufficient to obtain high conversions after 3 hours in a sample in the gas chromatography. grams the presence of 3% trans-1,3-pentadiene.

Sensitized photoreactions are of great technical importance today, e.g. B. for preparation example 4
active pharmaceutical ingredients, such as by Luhiisterin from 40

Ergosterol or from Ascaridol from ^ -Terpinen, furthermore in 100 ml benzene, which by means of passage from Stickfür technical syntheses, e.g. B. were freed of oxygen for the production of substance, one dissolves under Hydroperoxides or sulfinic acids. Nitrogen 1 g 9,10-dihydro - 9,10 - aethenoanthracene -

The following examples serve for further IHu · 11-carboxylic acid methyl ester. The solution will be

stration of the process. Temperatures are in degrees 45 closing with nitrogen bubbling through as in

Celsius indicated. Example 3 described, irradiated. The reaction will

B e i s η i e 1 1 followed by means of nuclear magnetic resonance spectroscopy. To

^p 48 hours one sets 47%, after 142 hours 87% 8 b,

30 mg of ci> l, 3-Pentadieri are in 50 ml of cyclo- 8c - dihydro - dibenzo [a, f] cyclopropa [c, d] - pentalen -

Dissolved hexane and solid under normal atmosphere for 50 8d (4bH) -carboxylic acid methyl ester.

3 hours in a round bottom flask from one side. .

irradiated with a mercury lamp. As a sensitivity example 5

A polyester film pushed into the flask becomes a generator. The procedure is analogous to that in Example 2

of 15 X 15 cm used. By cooling the indicated, but used in place of the mentioned

Reaction vessel is a copolymer of 90% vinylphenyl-

a reaction temperature of about 2O ⁰ C main- ketone and 10% methyl methacrylate, we obtain

obtain. The reaction solution becomes gasehromato- man after 7 hours 6.9% trans-1,3-pentadiene,

graphically examined for their composition. The copolymer is prepared as follows: 12 g

finds that already after 3 hours 1% trans-l, 3-penta-vinylphenyl ketone and 9.1 g methacrylic acid methyl

dien is present. 60 esters are dissolved in 125 ml of benzene and degassed.

Example 2 0.15 g of azoisobutyric acid dino-

tril admitted. The reaction mixture is under

136 mg cis-1,3-pentar! ^: s are kept at 50 ° in 150 ml of cyclo-vacuum for 25 hours. That

hexane dissolved, and the acidic reaction product contained in the solution is thereupon with 40 times

substance is displaced by introducing nitrogen. 65 volumes of petroleum ether (boiling point 40 to 65 °) are added

The and is stirred for 24 hours while continuously passing in nitrogen. The resulting low

Solution is repeated by a flashover for UV light after decanting the petroleum ether /

Passed a casual glass tube, the inner wall of which with a benzene mixture again with the same amount

7 8

Suspended petroleum ether. After 24 hours the example becomes 10

The product is filtered off and dried (melting point greater than the procedure in a manner analogous to that in Example 2)

160 °). given, but used in place of the mentioned

The coating of the glass tube is carried out analogously to the polymer, a polyimide made from pyromellitic anhydride

method described in Example 2. 5 and 4,4'-diaminodiphenyl ethers are obtained according to

". . ,, 4 hours a yield of trans-1,3-pentadiene of

Example 6 ιςο /

^r i) J / o

A solution of 5.6 g of freshly distilled maleic- The sensitizer is prepared as follows: One

acid anhydride in 150 ml of pure butyne-2 are in the solution of 1 g of said polyimide in 10 ml In the manner described in Example 2 while passing io Ν, Ν-dimethylacetamide is in a rotating and

irradiated by nitrogen. After 60 hours, horizontally stored glass tubes could be used. Under vacuum

10% crude S ^ -DimethylcyclobutenO-dicarbon- um, the tube is heated to 220 to 250 °. The final

Acid-1,2-anhydride can be obtained. Reversed hardening takes place through storage at 120 °

crystallize from η-hexane, a product is obtained with for at least 24 hours.

a melting point of 80 °. 15 r> ■ 1 1 1

^v B ei s ρ ι e I 11

Example 7 If the procedure is analogous to that in Example 2

120 ml of benzene are given by introducing stick-, but used in place of the mentioned

substance freed from oxygen. Under nitrogen, polymers become an adduct of diglycidyl phthalate

then 136 mg of cis-1,3 pentadiene dissolved. The lo ao and phthalic anhydride are obtained after 5 hours

Solution is now, as described in Example 2, in a yield of trans-1,3-pentadiene of 1.7%.

The adduct is produced as follows: 1.54 g

shine. In the gas chromatogram, after 3 hours, diglycidyl phthalate and 0.74 g of phthalic acid

the 8% and after 6 hours 15% trans-1,3-pentadiene anhvdrid are rubbed into a paste and in a

established. »5 rotating, horizontally mounted glass tubes equal

_R. · Ρ l 8 moderately distributed. Under vacuum, the mixture is with

^{ö p} 2 IR sources brought to reaction. The final

If the procedure is analogous to that in Example 2, curing is preceded by storage at 130 °

indicated, but used instead of the mentioned.

Polymers, a polychalkone from 4,4'-diacetyldiphenyl-30 is used in the above example with otherwise the same

ether and terephthalaldehyde, then one obtains according to the procedure in place of the adduct of phthalic acid

6 hours a yield of trans-1,3-pentadiene from diglycidyl ester and phthalic anhydride such

3.4%. from diglycidyl terephthalate and phthalic acid

The polychalkone is prepared as follows: 5.08 g of anhydride, after 1 hour 0.4% trans-

4,4'-diacetyldiphenyl ether and 2.68 g of terephthalic 35 1,3-pentadiene,

dialdehyde are heated in 70 ml of ethanol Example 12
solved. After adding solid NaOH up to slightly

alkaline reaction, the polychalcone slowly falls. If the procedure is analogous to that in Example 2

as a light precipitate. The reaction mixture given, but used in place of the mentioned

is stirred for a further 3 hours. The lower polymer is an adduct of diglycidyl phthalate

blow is filtered, washed in ethanol and with and thiophthalic anhydride, one obtains after

130 ° / 12 mm Hg dried for 15 hours. 5 hours a yield of trans-1,3-pentadiene of

Example 9 The adduct is prepared as follows: 1.54 g of phthalic

If the procedure is analogous to that given in Example 2, 45 acid diglycidyl ester and 0.9 g of thiophthalic anhydride are used, but instead of the above, as described in Example 11, an adduct of the compound of the formula is polymerized and cured in a glass polymer.

If one uses in the above example with otherwise the same » O - CH ₂ mode of operation instead of the adduct from phthalic acid

50 diglycidyl ester and thiophthalic anhydride'ein sol

CHes from diglycidyl terephthalate and thio- O phthalic anhydride is obtained after 4 hours O-CH ₂ 0.6% trans-1,3-pentadiene.

B e i s ρ i e 1 13
55

The procedure is analogous to that in Example 2

[3- (3 ', 4'-Epoxycydohexyl) -8,9-epoxy-2,4-dioxa- given, but used in place of the mentioned spiroundecanl polymer finely powdered 2-anthraquinone sulfo

and hexahydrophthalic anhydride, acid-Na-salt is obtained, which on a UV-transparent carrier after 7 hours a yield of trans-1,3-pentadiene 60 from a polymer of the compound of the form

of 4%. _n /-.τ.

The adduct is made as follows: A mixture ^υ <- «2 \

of 1.55 g of hexahydrophthalic anhydride and 3.2 g of _CH x "\

the compound of the above formula is uniformly _v

65 0-CH ₈ :

Splits. The tube is rotated in a horizontal position Oi

and irradiated with two IR sources After 24 hours

the pipe is stored at 130 ° for further hardening.

was applied, you get a after 4 hours Yield of tris-1,3-pentadiene of 0.6%.

The carrier layer is produced as follows: 3 g of the compound of the above formula are evenly distributed in a rotating, horizontally mounted glass tube. 150 mg (5%) of BF ₃ ether in 10 ml of absolute diethyl ether are then added. Immediately after the addition of the BF ₃ etherate, the finely powdered sensitizer is added in excess. The coated tube is then heated to about 50 ° under a slight vacuum and then stored at 50 ° for final curing. Sensitizer powder that is not embedded is blown out.

In the above example, with otherwise the same procedure, one uses instead of finely powdered 2-anthraquinone sulfonic acid sodium salt one of the sensitizers mentioned in the table below, applied in an analogous manner to the carrier layer, is obtained in this way the yields of trans-l, 3-pentadiene given in columns 3 and the table.

Tabel

Sensitizer Yield to 1 1.0 at on carrier layer trans game according to example 13 it, 3-pentadiene 2.2 No. nacl Complex hours 2.5 14th [Cr (urea) _e ] [Cr (CN) ₆ ] Complex 7th 2.8 15th [CriHarnstoffOeKCIO «), Complex 5 7.0 16 [Cr (urea) _e ] CI ₃ Complex 7th 2.8 17th [Cr (urea) _e ] (BF ₄ ) ₃ Complex 7th 18th [Cr (urea) _e ] ₂ (SO ₄ ) ₃ 5.3 Complex 7th 19th [Cr (urea) _e ] (HSO ₄ ) ₃ Complex 4th 20th [Cr (HaInStOfT) ₆ ] CI, and HgCl ₂ 7th

Example 21

20 g of -f-limonene are dissolved in 120 ml of 1,2,2-trifluorotrichloroethane solved. The solution is saturated with oxygen throughout the experiment

The irradiation is carried out, as described in the previous examples, in a glass tube, the inner wall of which is coated with a sensitizer system, consisting of one according to Example 13 manufactured UV-permeable carrier and in the surface of this carrier embedded Rose Bengal formula

KO

Cl

COOK

Cl Cl

Cl

After an irradiation time of 5 hours, 2.5% of the photooxidation product of limonene is obtained.

Example 22

If the procedure is analogous to that given in Example 13, but instead of 2-anthraquinone-sulfosniirp-TsIa-salt is used Cu-Phthäloc ^ ariir.-tetracsr boiic acid, on which by means of cationic polymerization Acrylophenone was grafted on, a yield of trans-1,3-pentadiene λ or is obtained after 7 hours 4.2 · / «■

Preparation of the sensitizer: 1.25 g Cu-Phthaio-

cyanine-tetracarboxylic acid are dissolved in 30 ml of thionyl chloride suspended. After adding 5 ml of dimethylformamide and 1 ml of triethylamine, the Gemisct heated to boiling for 18 hours and poured into petroleum ether after cooling.

The bluish black precipitate is filtered, dried and then suspended in 10 ml of benzene. After addition of 2.1 g in 10 m of benzene Acrylophenon a * over Na ₂ SO slowly to the prepared suspension., Dried solution of AgClO ₄ (3.6 g

added dropwise in 50 ml of toluene. The reaction mixture is stirred for a few hours, the resulting precipitate is isolated by decanting, washed and dried in vacuo

Claims (7)

Phase. For the two-phase system defined above, the terms "mobile" or "stationary" mean that one phase in the system moves in relation to the other 1. Process for the particular continuous being. Carrying out sensitized photoreactions, 'According to a preferred embodiment, results characterized in that the one the photoreactions in a photochemical Educts in liquid or dissolved form as mobile inert solvents. As educts (type I) Phase with an insoluble sensitizer as any compounds that energy is in come into question brings stationary phase into contact. Form of light from 200 to 800 nm, preferably 250 to 2. The method according to claim 1, characterized in that it absorbs 700 nm. At least one of the draws that the insoluble sensitizer in educts of the excited Sensibiüsatormolekül by in a thin layer. Energy transfer raised to a triplet state 3. The method according to claim 1 and 2, can thereby be. Type I educts are therefore z. B. characterized that one has the insoluble Sensibili- systems, the non-aromatic CC multiple bonds sator contained in a thin layer on a solid translucent, such as alkynes, cyclic and non-cyclic casual wearer pulls up. Olefins, dienes and polyenes, e.g. B. 2-butyne, 2-butene, 4. The method according to claim 1 to 3, characterized in- 1,3-pentadiene, l ^ .S-heptatrien.Cyclohexen, 1,3-cyclo denotes, that the insoluble Sensibili- hexadiene, cyclopentadiene, noibornadiene, ergosterol Sator in a thin transparent carrier layer or Santonin, also aryl olefins such as stilbene, phenyl intercalated. 20 cyclohexadiene, ^ -unsaturated carboxylic acids and 5. The method according to claim 1 to 4, characterized GE carboxylic acid esters, such as acrylic acid, or cinnamic acid indicates that the insoluble sensi- acetylenedicarboxylic acid and its es? er, \ - / 3-unsator uses a polymer film, saturated aldehydes such as cinnamaldehyde or geranial 6. The method according to claim 1 to 5, characterized by ge or neral, \ - / 2-unsaturated ketones such as acrylic, that the photoreactions in 25 ophenone, mesityl oxide, cyclohexenone, -v- / i-unsaturated a photochemically inert solvent by amides, such as acrylamide, ^ - / ^ - unsaturated nitriles, such as leads. Acrylonitrile, dicyanoacetylene, \ - / 9-unsaturated anhy- 7. Use an insoluble sensitiser such as maleic anhydride. for carrying out sensitized photoreactions. The process according to the invention can also be used in the liquid phase according to claims 1 to 6. 30 also apply to sensitized photooxidations, in which the oxygen is too oxy- Dating substrates represent the starting materials (type II). Examples of such starting materials are thiocarbonamides and thiosemicarbazones, hydrazones, cyclic and non- The present invention relates to a process for cyclic olefins or dienes, such as x-pinene, limonene, in particular continuous implementation of sensibili- cyclohexadiene, etc. and condensed aromatic-based photoreactions and the use of systems such as anthracene, naphthacene or 1,2-benzane-insoluble Sensitizers for carrying out sensitization.
bilized photoreactions in the liquid phase. Such compounds are used as sensitizers From the literature, various methods for 40 are in question, which result from the in the application to be carried out of sensitized photoreactions in ongoing excited states are not chemically or Known solutions. In all that have become known so far, change incomparably more slowly than the educts, In some cases, the sensitizer used is the least or only one of the absorbed energy dc at least partially in the solvent concerned, a small part vibratory or rotary, d. H. soluble, which of course to increase the efficiency of the 45 thermally degrade its excited singlet state Energy transfers is very desirable. Even if it has such a short lifespan that'une energy works Using polymeric sensitizers was always giving off or reacting with other molecules in a solvent used in which the concerned a diffusion controlled medium is not possible Compounds still had such great solubility, i. H. those that have a significant »intersystem that the concentration of the sensitizer in the 50 crossing «have quantum yield, and that in the ever-reaction solution for a homogeneous sensitization because the photochemically inert solution used was sufficient. However, these test arrangements had medium or in the liquid educt or in the liquid the great disadvantage that the sensitizer in the end educts are insoluble. the reaction is removed from the photo products again for the process according to the invention had to be separated, which also uses a continuous 55 photochemically inert solvent, so Leading the process impossible or difficult. this means solvents that are either in the This disadvantage can be avoided in that there is no absorption in the range from 200 to 800 nm Sensitizers are used which are in the react or not capable, in the sense of the above tion solution are completely insoluble. the definition of the starting materials The present invention therefore relates to a transfer to take over energy, or the mild ones drive to the particular continuous implementation of molecules occurring during the reaction sensitized photoreactions and does not react to it. characterized in that the starting materials are in liquid examples of such preferred solvents or dissolved form as mobile phase with a non-methyl alcohol, ethyl alcohol, cyclohexane, n-hexane, soluble sensitizer as stationary phase in contact 65 isopentane, benzene or fluorocarbons,
brings. The invention also relates to the sensitizers which correspond to the above definition using an insoluble sensitiser to talk through, are z. B. salts of sulfone or carbon lead sensitized photoreactions in liquid acids of mono- and diaryl ketones, for example