CS261433B1 - Photochromic 1,5-bis (Substituted phenyl) -3,3-diphenyl-1,5-pentadiones and their production process - Google Patents

Abstract

Photochromic 1,5-bis(substituted phenyl) 3,3-diphenyl-1,5-pentadiones of the general formula I, where X is alkyl with 1 to 2 carbons, alkoxy with 1 to 2 carbons or halogen, have photochromic properties. The method of their preparation consists in treating a mixture of compound II, where X has the above-mentioned meaning, with a base and benzophenone in anhydrous ether, tetrahydrofuran or dioxane at temperatures from -30 to +50 °C.

Description

The present invention relates to 1,5-bis (subst., Phenyl) 3,3-diphenyl-1,5-pentanedione GB (η (ε-α-β-piperazine) wherein X is alkyl having a carbon number of 1 to 2, alkoxyl having a carbon number of 1 to 2). to ^P 2 or Q, halogen.

So far the! only a derivative in which the X substituents are hydrogen atoms from acetophenone and benzophenone by base treatment was prepared.

Newly prepared diketones exhibit in the crystalline state significant photochromia after irradiation with sunlight. Said 1,5-diketones are potential precursors for the synthesis of heterocyclic compounds and can be used as components of photochromic compositions for use in the manufacture of photomaterials or materials for microelectronics. The novel diketones can be used to synthesize new heierocyclic compounds with photochromic properties. A process for the preparation of 1,3,3,5-tetrafenyl-1,5-pentanediones of formula I wherein X is as defined hereinabove is to treat the base with a mixture of compound II, wherein X is as defined above and benzophenone. Alkali metal hydrides, amides or alkoxides are used as bases. The reaction is carried out in anhydrous ether, tetrahydrofuran or dioxane at temperatures from -30 to +50 ° C.

The process for producing diketones I and their photochromic properties are shown in the following examples.

Example 1

Method of production of diketone I (X = CH3)

To a stirred and cooled suspension of 8 g (0.2 mol) of sodium amide was added a solution of 9.0 g (0.05 mol) of benzonphenone and 13.4 g (0.1 mol) of p-methylacetophenone in 25 ml of ether. The mixture was stirred at 0 ° C for 3 hours and then at room temperature for 2 days. After decomposition with water and extraction of the aqueous phase with benzene, the combined organic fractions were distilled with steam. The distillation residue was taken up in benzene, the combined organics were dried over sodium sulfate. and after evaporation of the solvent in vacuo, the oil was overlaid with ether. 4.5 g of 1,5-bis (p-tolyl) -3,3-diphenyl-1,5-pentadione (21% yield), m.p. 113-116 ° C, were obtained.

. Example 2

Method for producing diketone I (X = OCH 3)

To a stirred and cooled suspension of 8 g (0.2 mol) of sodium amide was added a solution of 9.0 g (0.05 mol) of benzophenone and 15.0 g (0.1 mol) of p-methoxyacetophenone in 25 ml of ether. The mixture was worked up in a similar manner to Example 1 to give 4.1 g of 1,5-bis (p-methoxyphenyl) -3,3-diphenyl-1,5-pentadione (18% yield). mp 156-157 ° C. Example 3

Method for producing diketone I (X-Br)

To a stirred and cooled suspension of 8 g (0.2 mol) of sodium amide was added a solution of 9.0 g (0.05 mol) of benzophenone and 19.9 g (0.1 mol) of p-bromoacetophenone in 25 ml of ether. The reaction mixture was worked up and the product was isolated in a similar manner to that in Example 1. 8.1 g of 1,5-bis (p-bromophenyl) 3,3-diphenyl-1,5-pentadione (45% yield) were obtained. ), which after recrystallization from benzene-petroleum ether had a melting point of 195-196 ° C. Analogously, 1,5-bis (p-fluorophenyl) -3,3-diphenyl-1,5-pentadione (X = F) was prepared in 26% yield with m.p. t. Mp 174-177 ° C.

Example 4

Photochromic properties of substances

Light induced color. change in substances I was observed in the solid state. When irradiating crystalline samples of substances I under the influence of sunlight, the required exposure time varies from fractions of a second to a few minutes. By keeping the colored crystals in the dark, there is a loss of color even within a few hours. A similar effect can also be obtained if the substance is dissolved or heated.

Substance I

X = H

X = CH 2

Color of the substance before irradiation

Color of the substance after irradiation colorless violet colorless red

2B1433

Claims (3)

S 6 2B1433 SUBJECT 1. Photochromic 1,5-bis (substituted phenyl) -3,3-diphenyl-1,5-pentadiones of the general formula I, wherein X is an alkyl having a carbon number of 1 to 2, al-alkoxy having a carbon number of 1 to 2 or a halo gene. 2. A process for producing 1,5-bis (phenyl substituent) 3,3-diphenyl-1,5-pentadiones as claimed in claim 1, wherein the base is subjected to a mixture of the compounds of formula (II) wherein: X is as defined above and benzophenone in anhydrous ether, tetrahydrofuran or dioxane at temperatures from -30 to + 50 ° C. 3. A method for producing a base according to claim 2, characterized in that alkali metal hydrides, amides or alkoxides are used as bases.