JPH0338549A - Production of substituted resorcinolic acid esters - Google Patents

Abstract

PURPOSE:To obtain the subject compounds in high yield and purity in one-step reaction by reacting substituted dihydroresorcinolic acid esters in the coexistence of cupric chloride as a halogenating agent and a metal salt as a dehydroalogenating agent. CONSTITUTION:A compound expressed by formula I (R is H or 1-3C alkyl; R1 is methyl or ethyl) is reacted with a compound expressed by the formula CuX2 (X is halogen) and a metal salt (e.g. a halide of Li or Na magnesium chloride or calcium bromide) in the coexistence thereof in an organic solvent at 10-150 deg.C, preferably 50-100 deg.C to provide compounds expressed by formula II. The compound expressed by the formula CuX2 is used in an amount of preferably 2-5mol based on 1mol compound expressed by formula I and the metal salt is used in an amount of preferably 0.5-3mol based on 1mol compound expressed by formula I. The resultant compounds expressed by formula II have oakmossy-like aroma and useful as a compounding material for oakmossy perfume compositions.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a novel method for producing substituted resorcinic acid esters having an oakmoss-like aroma.

More specifically, in the present invention, in the following formula (1), the three R's may be the same or different and each represents a hydrogen atom or an alkyl group of Cr''-Cs, and R1 is a methyl group or t; This invention relates to a novel method for producing substituted resorcinic acid esters represented by: where represents an ethyl group.

Included in the compound of formula (1), for example, methyl 3,6
-Simethyl resorcylate is a fragrance ingredient found in the solvent extract (oakmoss absolute or oakmoss concrete) of lichen that grows on oak bark, and is known as an important formulation ingredient for oakmoss-like fragrance compositions. ing.

(Prior art) Conventionally, the method for synthesizing substituted resorcinate esters is as follows:
Many proposals have been made. For example, halogenated substituted dihydroresorcinates are synthesized by treating substituted dihydroresorcinates with an alkali metal hypohalite such as sodium hypochlorite in an organic solvent in the presence of an acid, Next, a method has been proposed (see JP-A-63-51536) in which substituted resorcinic acid ester a is synthesized by subjecting the esters to a dehydrohalogenation reaction with a metal halide such as magnesium chloride in an organic solvent. There is.

(Problem to be solved by the invention) However, the method according to the above conventional proposal is based on the formula (1)
The number of steps for producing the compound is two steps; in addition, the reaction operation is complicated, and the results are not necessarily satisfactory and there are problems that need to be solved.

In order to solve the above problems, the present inventors conducted intensive research and found that from substituted dihydroresorcinic acid esters of the formula (2) described below, an easily operated and only one-step reaction can be achieved. The present invention has been completed by discovering that substituted resorcinic acid esters of the formula (1) useful as fragrance compounds can be synthesized in good yield and purity.

That is, the present invention selects cupric chloride as the halogenating agent and a metal salt as the dehydrohalogenating agent, and furthermore, by reacting the ferric chloride and the metal salt with the compound of formula (2) in the coexistence. , which is characterized by allowing the re-reaction of the halogenation reaction and the dehydrohalogenation agent reaction to proceed at once, thereby obtaining the compound of the formula (1) in good yield and purity in just one step of reaction. be.

Therefore, an object of the present invention is to provide a compound of formula (1) useful as a fragrance compound by a synthetic method that is advantageous compared to conventional synthetic methods.
An object of the present invention is to provide a method for producing a compound.

(Means for Solving the Problems) According to the present invention, substituted dihydroresorcinic acid esters of formula (2) below are mixed with cupric halides and metal salts in the presence of cupric halides and metal salts. The compound of formula (1) can be easily synthesized by reacting with copper and the metal salt.

The method for synthesizing the compound of formula (1) of the present invention is shown by a reaction formula:
For example, it can be expressed as follows.

(2) (1) In the formula, the three R's may be the same or different, and each represents a hydrogen atom or a C, -C, alkyl group,
RI represents a methyl group or an ethyl group, and X represents a halogen atom. A method for synthesizing the compound of formula (1) of the present invention will be described in detail below according to the above reaction formula.

The compound of formula (2), which is the starting material of the present invention, is a compound described in the literature, can be easily synthesized by a known method, and can be easily obtained from the market. Formula (2
) Specific examples of compounds include methyl dihydroresorcylate, methyl dihydroresorcylate, methyl 3-methyl dihydroresorcylate, ethyl 3-methyldihydroresorcylate, methyl 5-methyldihydroresorcylate. , ethyl 5-methyldihydroresorcylate, methyl 6-methyldihydroresorcylate, ethyl 6-methyldihydroresorcylate, methyl 3.5-
Dimethyl dihydroresorcylate, ethyl 3.5-dimethyldihydroresorcylate, methyl 3.6-dimethyldihydroresorcylate, ethyl 3.6-dimethyldihydroresorcylate, methyl 5.6-dimethyldihydroresorcylate lucylate, ethyl 5,6-dimethyldihydroresorcylate, methyl 3,5.6-)limethyldihydroresorcylate, ethyl 3,5.6-)limethyldihydroresorcylate, methyl 3-ethyl- Preferred examples include 6-methylcyhydroresorcylate and methyl 3-isopropyl-6-methylcyhydroresorcylate.

In the above reaction formula, to synthesize the compound of formula (1) from the compound of formula (2), the compound of formula (2) is mixed in an organic solvent in the presence of a cupric halide and a metal salt. This can be easily carried out by reacting with cupric oxide and the metal salt.

The above reaction is carried out, for example, at a temperature range of about 10° C. to about 150° C., more preferably about 0° C. to about 100° C., and usually for about 0.5 hours to about 20 hours, more preferably about 1 hour to This can be done in about 10 hours.

The amount of cupric halide used in this reaction is, for example, about 1 mol to about 1 mol per mol of the compound of formula (2).
An example of the amount is 0 mol, preferably about 2 mol to about 5 mol.

Specific examples of metal salts used in the above reaction include lithium chloride, lithium bromide, lithium iodide, lithium fluoride, sodium chloride, sodium bromide, sodium iodide, potassium fluoride, potassium chloride, Examples include potassium chloride, potassium iodide, magnesium chloride, magnesium bromide, calcium chloride, calcium bromide, barium chloride, etc. The amounts of these metal salts used are as follows:
For example, about 0.1 mol to about 10 mol, more preferably about 0.5 mol to about 3 mol, per 1 mol of the compound of formula (2).
The amount can be within a molar range.

In addition, the types of organic solvents used in this reaction include, for example, acetonitrile, acetamide, formamide,
N,N-dimethylformamide, N-methyl-2-pyrrolidone, hexamethylphosphoric triamide, pyridine, nitrobenzene and the like can be mentioned. There is no particular restriction on the amount of these organic solvents to be used, and for example, the amount preferably ranges from about 1 to about 50 times the weight of the compound of formula (2).

After the reaction is complete, extract, wash, dry, concentrate, and
By using purification means such as decolorization and recrystallization as necessary, a pure compound of formula (1) can be obtained in good yield and purity. Preferred specific examples of the compound of formula (1) of the present invention that can be obtained as described above include, for example, methyl resorcylate, ethyl resorcylate, methyl-3-methyl resorcylate, ethyl 3-methyl resorcylate, methyl 5-methylresorcylate, ethyl 5-methylresorcylate, methyl 6-methylresorcylate, ethyl 6-methylresorcylate, methyl 3
．． 5-dimethyl resorcylate, ethyl 3.5-dimethyl resorcylate, methyl 3,6-dimethyl resorcylate, ethyl 3,6-dimethyl resorcylate, methyl 5,6-dimethyl resorcylate, Ethyl 5.6-dimethyl resorcylate, Methyl 3.5.6-1-limethyl resorcylate, Ethyl 3,5.6-)limethyl resorcylate, Methyl 3-ethyl-6-methyl resorcylate and methyl 3-improvil-6-methyl resorcylate.

The present invention will be described in detail below with reference to Examples.

(Examples) Example 1 Synthesis of methyl 3,6-dimethyl resorcylate [compound of formula (1)].

In a 300 ml flask, 15.0 g (0,025 mol) of methyl 3,6-dimethyl dihydroresorsiole, anhydrous cupric chloride7. Charge Og (0.05 mol), 1.1 g (0.025 mol) of lithium chloride and 100 ml of acetonitrile and heat. 7 lux state (8
1'C) for 3 hours with stirring. After the reaction is complete, the reaction product is poured into water (300 ml) and extracted with ethyl acetate. Wash, dry, and concentrate the extracted layer. The obtained residue was decolorized with activated carbon, and the decolorized product was further recrystallized with toluene to obtain 3.6 g of a pure pale yellow compound of formula (1).

Melting point: 143°C Yield: 73% Examples 2 to 5 According to the method of Example 1, the corresponding formula (1
) is synthesized from substituted resorcinate esters. The results are shown in Table-1.

Table - (Effects of the Invention) The present invention provides a novel method for producing substituted resorcinic acid esters of the formula (1). This production method uses easily available substituted dihydroresorcinic acid esters of formula (2) as a starting material and produces formula (1) in good yield and purity through simple operations and only one step of reaction. This is a method of making synthetic leather from compounds such as

Furthermore, the compound of formula (1) has an oakmoss-like aroma and is useful as a compounding material for oakmoss-like fragrance compositions.

Claims (1)

[Claims] The following formula (2) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (2) In the formula, the three R's may be the same or different, and each represents a hydrogen atom or an alkyl group of C_1 to C_3 and R_1 represents a methyl group or an ethyl group, in an organic solvent, in the coexistence of a cupric halide and a metal salt, the cupric halide and the metal The following formula (1), which is characterized by reaction with a salt, includes mathematical formulas, chemical formulas, tables, etc.▼ (1) In the formula, the three Rs may be the same or different, and each represents a hydrogen atom or C_1 to C_3 represents an alkyl group, and R_1 represents a methyl group or an ethyl group.