SU1010053A1 - Method for producing pentene-4-in-2-ole-1 - Google Patents

Abstract

A method for producing penthen-β-in-2-ola-1 by reacting vinylacetylene with formaldehyde in the presence of a catalyst in a solvent medium, in order to increase the yield of the target product and simplify the process, potassium hydroxide promoted with ferric chloride with weight ratio

Description

SP

GS 1 The invention relates to a process for the preparation of pentenone-yn-2-ol-1, which finds use as an intermediate in the synthesis of drugs, as well as polymeric materials. A known method of producing pentenone-yn-2-ol-1, according to which the Grignard reagent obtained in the first stage by the reaction of magnesium with ethyl bromide is treated with vinylacetylene in the second stage and vinylethynylmagnesium bromide (Iocic reagent) is obtained, which is then reacted with paraform at 20-30 C for 21-25 h and get penten-A-yn-2-OL-1 with the release. The disadvantages of this method are the low yield of the target product, the multi-stage process and the complexity of the process associated with the production of magnesium organic reagents. There is also known a method for preparing pentene-4-yn-2-ol-1 by reacting vinyl bromide with propargyl alcohol in the presence of the Cu catapathic system (PdCf. In the middle of diethylamine at room temperature for three hours under a nitrogen atmosphere. After removing diethylamine under reduced pressure, water is added to the reaction mass, the mixture is extracted with benzene, and the benzene solution is chromatographed on an alumina column. Pentene-cn-2-ol-1 is isolated by fractional distillation with a comparative method The low yield of the desired product and the complexity of the process, associated with the use of an expensive catalyst that is lost without a hitch, as well as the laboriousness of the process associated with the need to chromatograph the mixture. The closest to the offer is the method of obtaining pentene-4-in- 2-ol-1 by the interaction of lO-Horo aqueous formaldehyde solution with vinylacetylene taken in a molar ratio of 3, in the presence of copper formate for 25 h under pressure IQ atm. The yield of the target product in this case is H. The disadvantages of this method are the low yield of the target product, the use of elevated pressure and 3 temperatures, which increase & the explosiveness of the process when working with acetylene and acetylenes, as well as the rather long duration of the process. The purpose of the invention is to increase the yield of penten-α-2-ol-1 and simplify the process. This goal is achieved by the method of obtaining pentene-α-2-ol-1 by reacting vinylacetylene with formaldehyde in the presence of a potassium hydroxide catalyst, coated with ferric chloride, taken respectively in a weight ratio (18-22): 1 in an organic solvent - dimethyl sulfoxide mixture diethyl ether, taken in a volume ratio of (): 1 at 10-20 ° C, and a molar ratio of vinyl acetylene and formaldehyde (1-1.5): 1. The yield of the target product is 63,, 6% with a process duration of 2.5 hours. The distinctive features of the proposed method are that potassium hydroxide promoted with chloric acid is used as a catalyst; {with a weight ratio equal to (18-22 ): 1, a mixture of dimethyl sulfoxide and diethyl ether is used as a solvent at a volume ratio of (2 -): 1, respectively, and the process is carried out at a molar ratio of vi (ethyl acetate with formaldehyde equal to (1: 1.5): 1 at 10-20 C. The proposed method allows to increase The yield of the target product is up to 63, instead of 3. By a known method while simplifying the process (reducing the temperature to 10-20 ° C and eliminating pressure). Carrying out the process under conditions different from those described does not ensure achievement of the set goal. So, at a ratio of dimethylsulfoxide-ether more than k: the yield of the target product remains almost unchanged, but at the same time the consumption of the more expensive component of the solvent dimethyl sulfoxide increases. With a dimethylsulfoxide: ether ratio of less than 2: 1, the yield of the target product is significantly reduced due to a decrease in the polarity of the medium. Likewise, an increase in the 1: OH: DEC-5 ratio of more than 22: 1 leads to a decrease in the yield of the target product, as well as in the case of a decrease.

Lowering the temperature higher leads to a decrease in yield due to the polymerization of penten-α-2-ol-1 in the presence of alkali, and lowering the temperature below JC leads to freezing of the solvent.

The process is conducted for 2.5 hours. Reducing the reaction time (1.5 hours or less) leads to a significant decrease in yield (37). The increase in the duration - to the resinification of vinyl acetylene alcohol under the action of alkali in a superbasic medium, which also leads to a decrease in yield.

Example 1. In a flask equipped with a stirrer, thermometer, reflux condenser, 200 ml of dimethyl sulfoxide and 100 ml of diethyl ether (2: 1 ratio of dimethyl sulfoxide ether) are placed; 11.13 g of powdered potassium hydroxide and 0.62 g of ferric chloride (KOHiFeCCj ratio 18: 1) and 90 ml (1.3 mol) of vinyl acetylene. The mixture is stirred for 1 hour at and 30 g (1.0 supposedly) paraform.

Stirring is continued for another 1 hour. Then, 100 ml of a saturated aqueous solution of calcium chloride is added to the mixture, extracted twice with ether (100 ml each), dried over MgSO4, and the ether is distilled off.

Distillation of the residue yielded 60.0 g (731 as a paraform) of pentei-4-yn-2-olas 59 s / 12 mm Hg; n% ° 1,936

Example 2. Analogously to example 1 of 103 ml (1.5 mol) of vinylacetylene and 30 g (1.0 mol) of paraform at 15 ° C in a medium of 225 ml of dimethyl sulfoxide and 75 ml of diethyl ether (dimethyl sulfoxide-3: 1 ratio)

in the presence of 11.2 g of powdered KOH and 0.55 g of FeCPj (KOH: FeCe ratio 20: 1), for 2.5 h, 61.5 g (75%) of the desired product are obtained.

Example 3. Analogously to example 1 from (1.0 mol) of vinyl acetylene and 30 g (1.0 mol) of paraform at 2pc in medium ml of dimethyl sulfoxide and 60 ml of diethyl ether (ratio, dimethyl sulphoxide-ether 4: 1) in the presence of 11.2 + g of potassium hydroxide and 0.51 g of ferric chloride (KOH: ReSe ratio 22: 1) for k h get 52 g (63.3) of the desired product.

Example k. Analogously to example 1 with the only difference that the ratio of DMSO-diethyl ether is taken equal to 3: 1, get 59.0 g (72%) of the target product.

Example 5 - Analogously to example 1 with the only difference that the ratio of DMSO-diethyl ether is taken to be: 1, 57.0 g (70%) of the desired product is obtained.

Example 6. Ana / yugichno example 1 with the only difference that the ratio of KOH: GeSbe, taken equal to 20: 1, receive 61.5 (75%) of the target product.

Example 7. Analogously to example 1 with the only difference that the ratio of KOH: FeC8 is taken equal to 22 :, 5 g (b 5.8%) of the desired product is obtained.

Example 8. Analogously to example 1 with the only difference that the process is carried out for k h receive 62 g (75.6%) of the target product.

Example 9 - Analogously to example 1 with the only difference that the process is carried out for 3 hours, get 60.7 g () of the target product.

Claims (1)

METHOD FOR PRODUCING PENTEN-4-IN-2-0LA-1 by the interaction of vinylacetylene with formaldehyde in the presence of a catalyst in a solvent medium, characterized in that in order to increase the yield of the target product and simplify the process, potassium hydroxide promoted with ferric chloride is used as a catalyst at weight ratio (18-22): 1, as a solvent a mixture of dimethyl sulfoxide with diethyl ether> with a volume ratio of respectively (2-4): 1 and the process is carried out at 1.0-20 ° C and a molar ratio of vinylacetylene and formaldehyde § (1-1 5): 1.SU 1010053