JPS6131095B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel brominated phthalate allyl ester compounds useful as raw materials for optical plastics. Conventionally, diallyl phthalate resins have high heat resistance,
It is known as a resin with excellent dimensional stability. On the other hand, as optical materials, polymethyl methacrylate, polycarbonate, polydiethylene glycol bisallyl carbonate (CR-39), etc. have been proposed, but polymethyl methacrylate and polycarbonate are both linear polymers and thermoplastic. Therefore, cutting, polishing, processing, etc. were difficult. CR-39 also has a lower refractive index than inorganic glass, and when used as a lens, it has the disadvantage of having a large center thickness and edge thickness. Therefore, the present invention was developed in the process of investigating ways to increase the refractive index of diallyl phthalate resin in order to develop a new plastic lens material that has excellent optical properties in addition to heat resistance and dimensional stability. A new brominated phthalate allyl ester compound with halogen introduced to increase the refractive index was synthesized, and polymers of these compounds have a high refractive index and are suitable as materials for optical elements such as lenses and prisms. They discovered this and completed the present invention. That is, the present invention consists of a novel brominated phthalic acid allyl ester compound represented by the following general formula. However, in the formula, R is a hydrogen atom, a chlorine atom or a methyl group. Examples of the novel brominated phthalic acid allyl ester compounds of the present invention include those shown by the following compound numbers. (1) Allyl 3,4,5,6-tetrabromophthalate, 2-chloro-2-propenyl (2) 2-chloro-2-propenyl 3,4,5,6-tetrabromophthalate, 2'-methyl-2'-propenyl (3) 3,4,5,6-tetrabromophthalic acid bis(2-chloro-2-propenyl) The novel brominated phthalic acid allyl ester compound of the present invention can be produced by the production method shown in the following reaction formula. Ru. Production method This production method is also applied when substituents R ₁ and R ₂ are the same or different. Here, R ₁ and R ₂ are a hydrogen atom, a chlorine atom, or a methyl group, and either R ₁ or R ₂ is a chlorine atom. That is, when 3,4,5,6-tetrabromophthalic anhydride (A) is reacted with R ₁ substituent allyl alcohol (B) to esterify phthalic anhydride (A), tetrabromophthalic acid Half ester (C) is obtained. However, R ₁ substituent allyl alcohol (B)
In, R ₁ is a hydrogen atom, a chlorine atom or a methyl group. Since the reaction rate at which half ester (C) turns into diester is slow, half ester (C) can be obtained in high yield. Next, the half ester (C) is reacted with an alkali metal hydroxide MOH to neutralize the half ester (C) and convert it into an alkali metal salt (D). In addition, in MOH and (D), M is Li, Na or K, preferably K. When the obtained alkali metal salt (D) is reacted with the 2-R _2- substituted allyl halide (E) in a polar aprotic solvent, the desired novel brominated phthalic acid allyl ester compound (F) is obtained. In the 2-R _2- substituted allyl halide (E),
R ₂ is a hydrogen atom, a chlorine atom or a methyl group, and X is a chlorine atom, a bromine atom or an iodine atom. Generally, the activity of these halogen atoms is I>Br>
Since it is Cl, if R ₂ is a halogen atom in the allyl halide (E), X needs to be a halogen atom that is equivalent to or more active than R ₂ . Furthermore, dimethyl sulfoxide or the like is used as the polar aprotic solvent. Production method This production method is applied when both substituents of the allyl group are chlorine atoms, and at least twice the mole of 2-chloro-substituted allyl halide (E) is added to dipotassium tetrabromophthalate (G) in a polar aprotic solvent. The desired novel brominated allyl phthalate ester (F') can be obtained. Note that a lithium salt or a sodium salt can be used instead of the dipotassium phthalate salt (G), but a dipotassium salt is preferred. The novel brominated phthalic acid allyl ester compound of the present invention can be easily homopolymerized or copolymerized with a radical polymerization initiator such as benzoyl peroxide, and the resulting novel compound of the present invention can be used as a main component. The polymer has excellent transparency and a high refractive index, and since it is a three-dimensional crosslinked product, it can be machined by cutting, polishing, etc., and is suitable as an optical plastic. Furthermore, since it has four bromine atoms in the benzene ring, it can also be used as a flame retardant. Hereinafter, the present invention will be explained in detail based on examples. Example 1 Allyl 3,4,5,6-tetrabromophthalate, 2-chloro-2-propenyl (compound no.
Production of (1)) As shown in the reaction formula below, a compound of compound number (1) was produced according to the production method. That is, 30 g (64.7 mmol) of 3,4,5,6-tetrabromophthalic anhydride (A) was added to 130 ml of allyl alcohol (B), and heated to 80°C while stirring to gradually dissolve. After dissolution, the mixture was kept at 80° C. for another 2 hours, then 4.5 g (68.9 mol) of KOH was added to neutralize it, and the mixture was cooled. The precipitated white crystals were separated by filtration, washed with a small amount of ethanol, and then dried to give potassium 3,4,5,6-tetrabromophthalate, 2-propenyl (D)33.4
g (yield 92%) was obtained. This material has a melting point of over 250℃ and can be used in IR.
1720cm ^-1 (ester carbonyl), 1600cm ^-1
(salt type carbonyl) showed characteristic absorption. 22.2 g of this compound (D) and 5.6 g of 2,3-dichloropropene (E) were mixed in 200 ml of dimethyl sulfoxide at 60%
When stirred at ℃ for 20 hours, compound (D) was dissolved to obtain a yellow transparent liquid. To this clear liquid was added 1N aqueous hydrochloric acid solution, and then extracted twice with 350 ml of ether. The ether extracts were combined, washed with water, dried over magnesium sulfate, and then the ether was distilled off. The residue was recrystallized from hexane to give 3, 4, 5,
Allyl 6-tetrabromophthalate, 2-chloro-
2-propenyl (F) (compound number (1)) 17.6g, yield
Got 75%. This compound (F) is a colorless needle crystal with mp94.5~96
It was warm at ℃. Elemental analysis values, characteristic infrared absorption, and NMR data are shown in the table below. Example 2 3,4,5,6-tetrabromophthalate bis(2-chloro-2-propenyl) (compound no.
Production of (3)) A compound of compound number (3) was produced according to the production method. 20 g (35.8 mmol) of dipotassium 3,4,5,6-tetrabromophthalate (G), 10 g ( _90.1
mmol) in 200 ml of dimethyl sulfoxide,
The reaction mixture was stirred at 60°C for one day and night to obtain a homogeneous solution. This solution was diluted with 1 part of a 1N aqueous hydrochloric acid solution, extracted several times with ether, and the combined ether solutions were washed with water, dried, and the ether was distilled off. When the residue was recrystallized from hexane, 3.
Bis(2-chloro-2-propenyl) 4,5,6-tetrabromophthalate (F) (compound number (3))
13.6g (yield 60%) was obtained. This substance was colorless needle-like crystals with a mp of 109 to 110°C. Elemental analysis values, characteristic infrared absorption and
NMR data are shown in the table below. Example 3 A new compound of compound number (2) was produced in the same manner as in Example 1. The results are also listed in the table below. 【table】

Claims (1)

[Scope of Claims] 1. A novel brominated phthalate allyl ester compound represented by the following general formula. However, in the formula, R is a hydrogen atom, a chlorine atom or a methyl group.