SU1245566A1 - Method of producing 4,4-dichlor-2-methyl-2-acyloxy-1,3-butadienes - Google Patents

Description

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The invention relates to a new process for the preparation of new 1,3-butadienes, specifically 4, 4-dichloro-2-methyl-1-acyloxy-1,3-butadienes, which can be used as intermediates in fine organic synthesis. and in polymer chemistry.

The purpose of the invention is to develop a new method for producing new 1,3-butadienes containing both halogen atoms and an acyloxy group, which can be used in the synthesis of polymers and in fine organic synthesis.

PRI me R 1. 4,4-Dnhlor-2- -methyl-1-acetoxy-1,3 butadiene (compound 1).

but). Solvent - ether: ethyl acetate (3: 1).

0.2 g-at (13 g) of crushed zinc, 30 ml of ether and 10 ml of ethyl acetate are introduced into the reaction flask equipped with a stirrer, reflux condenser and addition funnel. Then a mixture of 0.1 (18.8 g), 4,4,4-trhlchlor-2 methyl-2-butenal and 0.13 g-mol (10.2 g) of chloride acetyl and 15 ml of ether and 5 ml of ethyl acetate. The reaction mixture is heated until the start of the reaction, after which the reaction proceeds spontaneously. The temperature of the reaction mixture varies during the reaction from 40 to 45 seconds. After the completion of the dropping, the mixture is heated for 15 minutes, poured from zinc residues into another flask, then 0.13 (11.5 g) of dioxane is introduced into 80 ml of pentate, cooled, filtered off from precipitated zinc salts, the solvents are distilled off under vacuum. water jet pump (300-20 mm Hg) and the product is purified by distillation in vacuo. Yield 84% (16.4 g).

Compounds 2-4 were synthesized in a similar manner.

The interaction of 4,4,4-trichloro 2- -methylbutenal with zinc and s; lore acetyl at a ratio of 1: 2: 1 reagents under the conditions of example 1 gives 4,4-dichloro-2-methyl-1-acetoxy-1,3-butadiene in 75% yield.

A further increase in the proportion of chloro-, anhydride (1: 2: 1.5) practically does not increase the yield of the target product.

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(yield 84%) compared with the optimal ratio of 1: 2: 1.3. b). The solvent is ether. To the reaction flask, equipped with a stirrer, a reverse fridge and a dropping funnel, 0.2 g-at (13 g) of ground zinc and 40 ml of ether are added. Then, a mixture of 0.1 g-mol (18.8 g) 4, 4,4-trichloro-2-methyl-2-butenal and O, 13 g-mol (10.2 g) acetyl chloride in 15 ml of ether. The reaction mixture is heated until the start of the reaction, after which the reaction proceeds spontaneously. The temperature of the reaction mixture varies from 36 to. Further processing of the reaction mixture is similar to Example 20 20a. Yield 83% (16.2 g) -.

at). The solvent is ethyl acetate. In a reaction flask equipped with a stirrer, a reflux condenser and a dropping funnel, 25 0.2 g-at (13 g) of ground c. small chips of zinc and 40 ml of ethyl acetate. Then a mixture of 0.1 g-mol (18.8 g) of 4,4,4-trichloro-30 -2 methyl-2-butenal and 0.13 g-mol (10, 2 g) acetyl chloride in 15 ml of ethyl acetate. The reaction mixture is heated until the start of the reaction, after which the reaction proceeds spontaneously. ,, Adjusting the dripping speed

mixtures (1-2 drops per second.) Maintain the temperature of the reaction mixture within 40-5p C (better). After completion of the dropping, the 4Q mixture is heated for 15 minutes at 45 ° C. Further processing of the mixture is similar to the example of Ta. Yield 81% (15.8 g) ..

Example 2, 4,4-dichloro-2-methyl-1 pivaloyloxy-1,3-butadiene j (compound 5) table.

In a reaction flask equipped with a stirrer, a reflux condenser, and an addition funnel, 0.2 g-at (13 g) of ground zinc, 30 ml of ether, and 10 ml of ethyl acetate are added. Then a mixture of 0, .1 g-mol (18.8 g) of 4,4,4-trichlor--2-methyl-2-butenal and 0.13 g-mol

55 (15.7 g) pivaloyl chloride in

15 ml of ether and 5 ml of ethyl acetate. Further operations are carried out analogously to example 1a. Yield 73% (17.3 g).

Outputs, reaction conditions and physicochemical constants of the compounds 1-5 obtained are presented in the table.

The structure of the compounds was proved by their elemental analysis, as well as by IR, IMP and NQR methods of C1 spectroscopy.

In the IR spectra, there are characteristic absorption bands of the carbonyl GROUP 1665-1700 cm (), double bonds 1635-1640 cm () and 1600-1605 ().

PMR spectra show that the target products are formed as a mixture of two geometric isomers Z and E in a ratio of 1: (3-5), respectively. For example, PMR spectrum 4,4 dichloro -2 -2 methyl-1-acetoxy-1,3-butadiene (S, ppm, in CCl;); for E isomer 2455664

6.27 (-CH),, 34 (CHO), 1.98 (CH, C), 2.14 (); for the Z-isomer, 6.70 (CH), 7.00 (CHO), -1.97 (CH3C), -2.13 (CHjCOO). 5 In the Yak C1 E-isomer spectrum, there are two resonance lines, corresponding to two chlorine atoms of the dichlorvine () group: 36.529-36.822 and 36.255-36.643 MHz.

10 Target compounds are colorless crystalline substances with low melting points, soluble in organic solvents — ether, acetone, alcohol, etc.

ts Double recrystallization from pentane makes it possible to eliminate the Z-isomer and to obtain the pure E - isomers of 4,4-dichloro-2 methyl-1-acyloxy-1,3-butadienes, for which in the table

20 shows the likep and NQR spectra of C1.,

Claims (1)

METHOD FOR PRODUCING 4,4-Dichloro-2-methyl-1-acyloxy-1,3-butadiene of the general formula 'CC1 ₂ = CH-C (CH ₃ ) = CHOCOR where R is CH ₃ , CjHj, C ₃ N _G , is -C ₃ H ₇ , tert- ₄ H ₉ , characterized in that 4,4,4-trichloro-2-methyl-2-butenal is reacted with .zinc and the acid chloride of the corresponding aliphatic acid in a molar ratio of 1: 2 : (1-1.5), respectively, in ether, · ethyl acetate or a mixture thereof with a ratio of ether and ethyl acetate 3: 1 at 36-50 ° C. N5) 4 · λ ”SL SP 05 05