JPH035377B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to 2,3-diacetylnorbornadiene, a novel compound useful as a synthetic intermediate for producing various norbornadiene derivatives, and a method for producing the same. In recent years, norbornadiene compounds have attracted much attention and research from the viewpoint of their physiological activity and application to solar energy utilization. Therefore, many norbornadiene derivatives having substituents have been synthesized so far. The present inventors have been conducting intensive research on the synthesis of various norbornadiene compounds, and have discovered that 2,3-diacetylnorbornadiene, which has not been published in the past, has value as an intermediate for the synthesis of many useful norbornadiene compounds. It was discovered that the compound itself has high photoreactivity. For this reason, the present inventors investigated various methods for synthesizing this new compound and found an inexpensive method for producing it. That is, 2,3-diacetylnorbornadiene according to the present invention has a chemical structure represented by the formula (), and can be led to various derivatives using its carbonyl group. For example, by treatment with diisobutylaluminum hydride, 2,3-dihydroxyethylnorbonadiene represented by the formula () can be obtained, and by reacting with organolithium (RLi) or Grignard reagent (RMgX), the formula () This can lead to the derivative represented by Furthermore, when amines are reacted, corresponding imines can be obtained, and especially when hydrazine is reacted, the pyridazine derivative represented by the formula () can be obtained in high yield.

【formula】

【formula】

【formula】

[Formula] (In the formula, Me represents a methyl group, R represents an alkyl group, an aryl group, an allyl group, etc.) Among these norbornadiene derivatives, the pyridazine derivative represented by the formula () is a hitherto unpublished compound, It has interesting photoreactivity and has utility as a light energy storage material as described below. 2,3-Diacetylnorbornadiene according to the present invention includes cyclopentadiene and 3-hexine-
It can be produced by Diels-Alder addition reaction with 2,5-dione. This production method is easy to perform reaction operations and has a high yield of the target product, and is suitable as a method for producing the compound of the present invention, and is the second claimed invention. The reaction is carried out in a solvent such as aromatic hydrocarbons such as benzene and toluene, ethers such as ethyl ether and THF, halogenated hydrocarbons such as methylene chloride and chlorobenzene, and esters such as ethyl acetate, or in the presence of raw materials. of cyclopentadiene as a solvent. The reaction can be carried out at a temperature of -40° to 80°, but if it is too low, the reaction rate will be slow, and if it is too high, a large amount of cyclopentadiene dimer will be produced. It is preferable to carry out within a range. In addition to the target 2,3-diacetylnorbornadiene, the reactants include cyclopentadiene dimer, the raw materials cyclopentadiene and 3-hexyne 2,5-
It contains dione and trace amounts of by-products, and the yield of the target product is approximately 90-100%. The target product can be easily purified by column chromatography, but if the amount of cyclopentadiene dimer is small, the target product can be directly crystallized from the oily reaction crude product using n-hexane. be able to. If further recrystallization is performed,
Almost 100% purity can be obtained. Among the compounds that can be produced using the compound of the present invention as a synthetic intermediate, the pyridazine derivative represented by the above formula () can easily and quickly absorb sunlight as shown in the reaction formula below without using a sensitizer. The photoisomerized product undergoes an exothermic reaction upon contact with the catalyst and returns to the original compound. Among such pyridazine derivatives, those in which R is a lower alkyl group such as a methyl group or an ethyl group are preferred. The two R's may be different from each other. Among these pyridazine derivatives, for example, in the case of the 1,4-dimethyl compound, 1 of the wavelength of light showing the maximum absorption peak is
is 328 nm, the optical absorption end of these derivatives is generally around 440 nm, and the quantum yield of photoisomerization is
Indicates 0.4 or higher. As the reverse reaction catalyst, metal complexes, basic catalysts, etc. are advantageous, and the calorific value during the reverse reaction is generally 14 to 15 Kcal/mol. Furthermore, since this photoisomerized product is stable and can be stored for a long time, this pyridazine derivative is extremely effective as a storage material for solar energy. EXAMPLES The present invention will be specifically explained below using examples, reference examples, etc., but the present invention is not limited to these examples. Example 1 3-hexyne-2,5-dione 5.5g (50m
mol) at 0℃, 16.6 g of cyclopentadiene
(100 mmol) and stirred at 10-15°C for 4 hours. Unreacted cyclopentadiene was distilled off under reduced pressure to obtain 9.7 g of an oily residue. Purification was performed using silica gel column chromatography (developing solvent: hexane/ethyl acetate = 5 mixed solvent), and 2,3-
8.36 g of white crystals of diacetylnorbornadiene were obtained (yield 95%). The physical property values are shown below. Melting point: 43.0-43.5℃ NMR (δppm); 6.91 (t, 2H,

[Formula]), 3.91 (m, 2H,

[Formula]), 2.28(s, 6H, -
_CH3 ), 1.95~2.15(m, 2H,

[Formula]), MS; M/e=178 (P ⁺ ) IR; 1680, 1655, 1605, 1235, 1020, 815,
730, 615 cm ^-1 UV; λ ^CH ₃ ^CN/max , 249 mm, 215 mm logεmax 3.58, 3.51 Example 2 3-hexyne 2,5-dione 5.5 g (50 mmol)
was dissolved in 50 ml of methylene chloride, 3.96 g (60 mmol) of cyclopentadiene was added at room temperature, and the mixture was stirred for 8 hours. After distilling off the solvent and cyclopentadiene under reduced pressure, the residue was dissolved in n-hexane, and white crystals precipitated under ice cooling were separated to obtain 8.0 g of 2,3-diacetylnorbornadiene (yield 91%). Its physical properties were the same as in Example 1. Reference example 1 1,2-diacetylnorbornadiene 1.76g
(10 mmol) was dissolved in 10 ml of methylene chloride and stirred _at room temperature ^.
0.68 g (10 mmol) of ^NH3.Cl- ) was dissolved in 10 _ml of ethanol and added. After 2 hours, additional methylene chloride was added, washed with dilute aqueous sodium bicarbonate solution, then dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure to yield 1.63 g of a brown oil. Silica gel column chromatography was performed using a chloroform-methanol mixed solvent as a developing solvent to remove colored components and origin components, and 1,4-dimethyl-5,8-dihydro-5,8-methanophthalazine was obtained as a pale yellow oil. (Pyridazine derivative) 1.48g was obtained (yield 86%). ((Physical property value)) 〇 Nuclear magnetic resonance spectrum (solvent CDCl ₃ ) δ value (ppm) 6.81 Triplet line (coupling constant 4H ₈ ) 2H,

【formula】 4.00 Multiplet 2H,

[Formula] 2.64 Singlet 6H, CH ₃ − 2.1~2.4 Multiplet 2H,

[Formula] 〇Infrared absorption spectrum 3000, 1570, 1390 1300, 825,
735cm ^-1 〇 Mass spectrum M/e = 172 (P ⁺ ) 〇 Ultraviolet absorption spectrum λ ^CH ₃ ^CN/max 221nm, 266nm, 328nm logεmax 3.56, 3.36, 2.71 Reference example 2 1,4- obtained in Reference example 1 dimethyl-5,8
-Dihydro-5,8 methanophthalazine (pyridazine derivative) 172 mg (1 mmol) was dissolved in 40 ml of acetonitrile and irradiated with ultraviolet rays for 30 minutes. The acetonitrile was distilled off under reduced pressure, and a pale yellow oil was obtained.
11-dimethyl-9,10diazatetracyclo[5,
4,0,0 ^2,4 , 0 ^3,6 ] undeca-1(7),8,10-triene was obtained. The nuclear magnetic resonance spectrum of this product is as follows. (Proton) (Solvent CDCl ₃ ) δ value (ppm) 3.2-3.5 Multiplet 2H 2.8-3.1 Multiplet 1H 2.78 Singlet 3H 2.6 Multiplet 1H 2.53 Singlet 3H 2.1-2.3 Multiplet 1H 0.62 Multiplet 1H ( Pepper

Claims (1)

[Claims] 1. 2,3-diacetylnorbornadiene represented by formula (). 2 Cyclopentadiene and 3-hexyne-2,5
- characterized by an addition reaction with a dione;
A method for producing 2,3-diacetylnorbornadiene.