JPS6245233B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to 2-(substituted 1-alkenyl)-4-isopropyl-5,5-dimethyl-1,3-dioxane derivatives and methods for producing the same. The present inventors previously reported that 2,2,4-trimethyl-
We have discovered that 1,3-pentadiol reacts with various carbonyl compounds due to its structural characteristics to form a cyclic acetal compound with an extremely low freezing point and excellent fluidity. The present inventors further demonstrated that when the above 2,2,4-trimethyl-1,3-pentanediol was reacted with a carbonyl compound having an α/β-ethylenically unsaturated bond, it maintained a low freezing point and excellent flow properties. It has been found that a polymerizable cyclic acetal compound can be obtained. The obtained compound is useful as a polymer modifier, particularly as a photosensitive resin modifier by utilizing its excellent photocurability. Also, by applying its low freezing point and excellent fluidity, it is useful as a solvent for special inks (self-curing solvents) such as high-speed recording ink jets, solvents for adhesives, solvents for sealants, paint additives, etc. The present invention is characterized by dehydrating 2,2,4-trimethyl-1,3-pentanediol and an aldehyde or ketone having an α/β-ethylenically unsaturated bond.
4-isopropyl-5,5-dimethyl-1,3-
A method for producing a dioxane derivative is provided. 2,2,4-trimethyl-1, used in the present invention
In 3-pentanediol, the two hydroxyl groups are sterically positioned at suitable positions to form a cyclic acetal, and the compound of the present invention can be obtained in high yield. Examples of aldehydes or ketones having α/β-ethylenically unsaturated bonds include acrolein,
Methyl vinyl ketone, crotonaldehyde, metaacrolein, α-ethyl acrolein, α-methyl crotonaldehyde, β-methyl crotonaldehyde, 2-methyl-2-pentenal, mesityl oxide, isobutylidene acetone, ethyl vinyl ketone, methyl propenyl Examples include ketone, isobutyl vinyl ketone, and the like. The reaction between 2,2,4-trimethyl-1,3-pentadiol and the above aldehyde or ketone is expressed by the formula: [In the formula, R ₁ is hydrogen or a C ₁ to C ₄ alkyl group, R ₂
is hydrogen or _C1 - _C2 alkyl group, _R3 and _R4
each independently represents hydrogen or a C ₁ to C ₄ alkyl group. The above reaction uses approximately equal moles of diol and aldehyde (or ketone), a suitable azeotropic dehydration solvent such as benzene, and the presence of a conventional esterification catalyst such as p-toluenesulfonic acid. It is preferable to carry out the reaction under normal conditions of heating and refluxing, and removing the produced water from the system. A reaction time of 1 to 2 hours is usually sufficient, and approximately
The target compound can be obtained with a yield of 90% or more. In order to prevent polymerization during the reaction, it is preferable to add, for example, a small amount of hydroquinone (about 1% by weight based on the aldehyde or ketone) as a polymerization inhibitor. This dehydration reaction can be carried out without a solvent, but the azeotropic dehydration reaction using an aromatic solvent is easy to moderately control the reaction conditions, and has extremely high yields, making it extremely efficient in terms of industrial productivity. Excellent. 2-(substituted 1-alkenyl)- obtained in the present invention
4-isopropyl-5,5-dimethyl-1,3-
Dioxane derivatives are extremely stable compounds because their cyclic acetals have a characteristic hindered structure. Among the compounds of the present invention, compounds that are expected to be particularly useful in practical terms in terms of photocuring properties, fluidity, etc. are:
2-vinyl-4-isopropyl-5,5-dimethyl 1,3-dioxane, 2-methyl-2-vinyl-4-isopropyl-5,5-dimethyl-1,3
-dioxane, etc. Table 1 below shows the carbonyl compounds used as raw materials and the substituents of the corresponding products.

【table】

[Table] The present invention will be explained below with reference to Examples. Example 1 0.73 mol (106.7 g) of 2,2,4-trimethyl-1,3-pentanediol, 0.74 mol (41.4 g) of acrolein and 0.2 g of p-toluenesulfonic acid were dissolved in 200 ml of benzene, and this was dissolved in Dean Stark The mixture was placed in a flask equipped with a stirrer and a distiller, and the water produced was removed from the system by azeotropy while heating and refluxing, and the mixture was stirred for 2 hours. Anhydrous potassium carbonate was added to the reaction mixture to neutralize it, and after drying and removing the salt,
Benzene was distilled off from the liquid, followed by distillation under reduced pressure to obtain 125 g of a fraction (yield: 93%) at 0.6 mmHg and 50°C. The physical properties of the product are shown in Table-2. When the product was subjected to gas chromatography under the following conditions, it showed a single peak as shown in FIG. Gas chromatography conditions Detector: FID Column (made of stainless steel): Length 1m Packing material GE-30 Carrier gas: Nitrogen gas 30ml/min Injection temperature: 210℃ Development temperature: 190℃ Chart feed rate: 20cm/min Example 2 2・2,4-trimethyl-1,3-pentadiol 0.73 mol (106.7 g), methyl vinyl ketone
0.74 mol (53.7 g) and 0.2 p-toluenesulfonic acid
Dissolve g in 200ml of benzene and add
The mixture was charged into a flask equipped with a stirrer equipped with a Stark distiller, and stirred for 2 hours while heating to reflux and removing the produced water from the system by azeotropy. The reaction mixture was neutralized by adding anhydrous potassium carbonate, dried, the salt was separated, benzene was distilled off from the liquid, and then distilled under reduced pressure to obtain 140 g of distillate at 0.55 mmHg and 40°C (yield 95
%) was obtained. The physical properties of the product are shown in Table-2. When the product was subjected to gas chromatography under the following conditions, it showed a single peak as shown in FIG. Gas chromatography conditions Detector: FID Column (stainless steel): Length 1m Carrier gas: Nitrogen gas 30ml/min Injection temperature: 210℃ Development temperature: 190℃ Chart feed rate: 20mm/min

【table】 [Brief explanation of the drawing]

Figures 1, 2 and 3 are 2-vinyl-4-isopropyl-5,5-dimethyl-
IR chart, NMR chart and GLC of 1,3-dioxane; Figures 4, 5 and 6 are for 2-methyl-2-vinyl-4-isopropyl-5,5-dimethyl-1,3-dioxane, respectively. of
IR chart, NMR chart and GLC are shown.

Claims (1)

[Claims] 1. General formula: [In the formula, R ₁ is hydrogen or a C ₁ to C ₄ alkyl group, R ₂
is hydrogen or _C1 - _C2 alkyl group, _R3 and _R4
each independently represents hydrogen or a C ₁ to C ₄ alkyl group] 2-(substituted 1-alkenyl)-4-isopropyl-5,5-dimethyl-
1,3-dioxane derivative. 2 2-(Substituted 1-alkenyl)-4 characterized by dehydrating 2,2,4-trimethyl-1,3-pentanediol and an aldehyde or ketone having an α/β-ethylenically unsaturated bond. −
A method for producing an isopropyl-5,5-dimethyl-1,3-dioxane derivative.