JPS5939890A - Phenyl-substituted 2-(1-alkenyl)-4-isopropyl-5,5-dimethyl-1, 3-dioxane derivative - Google Patents

Abstract

NEW MATERIAL:A compound shown by the formula I (R1 is 1-4C alkyl, or phenyl; R2 is H, 1-2C alkyl, or phenyl; R3 and R4 are H, 1-4C alkyl, or phenyl; with the proviso that at least one of R1-R4 is phenyl). EXAMPLE:2-Methyl-2-styryl-4-isopropyl-5,5-dimethyl-1,3-dioxane. USE:A polymer improver (especially for photosensitive resin), and reodorant. PROCESS:2,2,4-Trimethyl-1,3-pentanediol shown by the formula II is reacted with an aldehyde or ketone (e.g., compound shown by the formula III, etc.) having an alpha, beta-ethylene unsaturated bond and at least one phenyl group in an approximately equimolar ratio in an azeotropic solvent such as preferably benzene, etc. in the presence of an esterifying catalyst such as p-toluenesulfonic acid, etc. usually under reflux conditions by heating.

Description

DETAILED DESCRIPTION OF THE INVENTION Invention 1d Phenyl-substituted 2-(1-alkeny)V)-
The present invention relates to a 4-isopropyl-5,5-dimethyl-1,3-dioxane derivative and a method for producing the same.

The present inventors have found that by reacting 2,2.4-)riftyl-1,3-bentanediol with a carbonyl compound having an α,β-ethylenically unsaturated bond, a polymerizable cyclic acetal compound having an aroma can be obtained. I discovered that. The obtained compound is useful as a polymer modifier, particularly as a photosensitive resin modifier by utilizing its excellent photocurability. Furthermore, due to its excellent aroma, it is useful as a raw material for various fragrances and as a flavoring agent.

The present invention is characterized in that 2,2.4-)dimethyl-1,8-bentanediol and an aldehyde or ketone having an α,β-ethylenically unsaturated bond and at least one phenyl group are subjected to a dehydration reaction. ftJls2
A method for producing -(1-alkenyl)-41sopropyl-5,5-dimethyl-1,3-dioxane derivative° is provided.

The 2,2.4-)rifthyl-1,3-bentanediol used in the present invention has two hydroxyl groups in positions suitable for forming a cyclic acetal from a steric perspective, and the compound of the present invention can be produced in high yield. Obtainable.

Examples of the aldehyde or ketone having an α,β-ethylenically unsaturated bond and at least one phenyl group include cinnamaldehyde, benzalacetone, α-phenylacrolein, feninovinyl ketone, α-methylchalcone, benzalace-1-phenone, etc. is exemplified.

2.2.4-) Dimethyl-1,3-penta, diolt The reaction with the above aldehytade or ketone is carried out by the formula: [wherein R1 is hydrogen, C1 to C4 alkyl group or tahaphenyl group, R2 is hydrogen, 01 ~C2 alkyl group or phenyl group, R3 and R4 are each independently hydrogen, C2
The alkyl group of 1-C4 is a phenyl group, and R1,
At least one of R2, R3 and R4 represents a phenyl group.

Reaction of LLL-U Using approximately equal moles of diol and aldehyde (or ketone), an ordinary esterification reaction using an excessive azeotropic solvent such as benzene, etc.
, for example, tbp-) In the presence of luenesulfonic acid, the reaction is preferably carried out under constant heating and reflux conditions, and the produced water is taken out of the thread.

A reaction time of 1 to 2 hours is usually sufficient, and the target compound can be obtained with a yield of about 90% or more.

In order to prevent polymerization during the reaction, it is advisable to add, for example, a small amount of hydroquinone (approximately 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 an extremely high yield, so it is extremely effective in terms of industrial productivity. Excellent.

Phenyl-substituted 2-(1-alkeni/L) obtained in the present invention
/)-4-isopropifure5,5-dimethyl-1,3
-Dioxane derivatives are extremely stable compounds because their cyclic acetals have a hindered structure.

Among the compounds of the present invention, compounds expected to be particularly useful in practical use as polymer modifiers, flavoring agents, etc. are 2-methyl-2-nutyryl-4-isopropyl-5,5-dimethyl-1,8- These include dioxane, 2-styryl-4-isopropyl-5,5-dimethyl-1°3-dioxane, and the like.

Table 1 below shows the carbonyl compounds used as raw materials and the substituents of the corresponding products.

The present invention will be explained below with reference to Examples.

Example 1 2, 2, 4. -) samethyl-1,3-bentanediol 0.73 mol (In6.7y), cinnamaldehyde 0
．． Dissolve 02 g of 74 mol (97°8F/) and pth) to 2 N (1 ml) of benzene, charge this into a flask equipped with a stirrer and add the distillation # of Dean-Nutak, and add water under reflux. The reaction mixture was stirred for 2 hours while being removed from the system by boiling. Anhydrous potassium carbonate was added to the reaction mixture to neutralize it, and after drying, the salt was removed from the furnace, and all benzene was distilled off from the furnace liquid, followed by #: Seri distillation. Then 133~135°010.55 decoy part 176M
A yield of 92%) was obtained. The physical properties of the product are shown in Table 2.

When the product was subjected to gas chromatography under conditions where the product was not present, a single peak as shown in FIG. 3 was observed.

Gas chromatography conditions Detector: FID column (stainless steel 'lt, J), m packing material 5E-
3Q Carrier Ganu: Nitrogen Ganu 80. nt/min injection? fft+i:,,210”C development temperature
: 190°C Chart feed rate : 2.5/min Example 2 2.2.4-)Samethyl-1,3-bentanediol 0
．． 78mo tvc 1116.7 f) VC Henza/y
Ar-h)one 0.74 mol (1(18,2i and p-)
This was dissolved in 200 ml of 2FK benzene and charged into a flask equipped with a Dean Nutak distiller and a stirrer, and stirred for 2 hours while heating and refluxing to remove the generated water by azeotropy. .

The reaction mixture was neutralized by adding anhydrous potassium carbonate, dried, filtered to remove the salt, distilled off benzene from the furnace solution, and then distilled under reduced pressure to obtain a distillate of 188f (yield: 102-104°C). 91%). The physical properties of the product are shown in Table-2.

When the product was subjected to Cass chromatography under the following conditions, a single peak as shown in Figure 6 was obtained. Indicated.

Gas chromatography conditions Detector: FID Column (stainless steel): Length 1m Packing material 5F-80 Carrier gun: Nitrogen gas, 80m//min Injection mtK: 220"C Development temperature: 19
0'C Chart feed speed = 55y minutes

[Brief explanation of the drawing]

1st South, 2nd and 3rd (2) are infrared absorption spectra of 2-styryl-4-isopropy/L'-5,5-dimethyl-1°3-dioxane, N IVt R
b and a gas chromatograph. Figures 4, 5 and 6 (2) are 2-methyl-2-styryl-4-isopropyl-5,5-cymetyl, respectively.
Infrared absorption spectrum of v-1,3-dioxane, NMR
and a gas chromatograph. Patent applicant Neos Co., Ltd. Representative, Patent Attorney Hao Aoyama and 1 other person

Claims (1)

[Claims] 1. General formula: [In the formula, R1 is hydrogen, 01 to C4 alkyl group or phenyl group, R2 is hydrogen, 01 to C2 alkyl group or phenyl group, R3 and R4 are each independently hydrogen,
The C1 to C4 alkyl group is a phenyl group, and R
1, R2, R3 and R4, at least 7 of which represent phenyl groups] lerphenyl-substituted 2-(1-alkenyl)-4-isopropyl-5,5-dimethyl-1
, 3-dioxane derivative. 2. Phenyl substitution 2 characterized by dehydrating 2.2.4-trimethyl-1,3-bentanediol and an aldehyde or ketone having an a, β-ethylenically unsaturated bond and at least one phenyl group -(1-
A method for producing (alkenyl)-4-isopropy)V-5,5-dimethyl-1,3-dioxane derivative. 3. The method according to item 2, wherein the dehydration reaction is carried out in the presence of an etherification catalyst.