CS269558B1 - Preparation of 2-methyl-4- (2'6'6'-trimethyl-1- 1-cyclohexenyl) -butene-2-alu-1. - Google Patents

Abstract

method of preparation of 2-methyl-4-[2,6] from 6'-tri·*tyl-1-cyclonexenyl[-buten-2--alu-1 from trimethylaulfonium salt and 4-[2[6'6']-triaethyl-1-cyclohexenyl[-3-buten-2-one under the A adzulfose catalysis. Solutions aa and ož used in the pharmaceutical industry in the synthesis of vit.A,

Description

The invention relates to the apoab preparation of 2-methyl-4-[2R6'6'-trimethyl-1-cyclohexenyl]-buten-2-alu-1, abbreviated name 6^ _4- aldehyde, formula I, from B-ionone and trimethylsulfonium salt via /R,S/-/E/-2-methyl-4-/2*6f6*-trimethyl-1-cyclohexenyl/-1,2-epoxy-3~but<lnu/ep~oxide II/ under conditions of interphase catalysis.

II

According to the current state, C ₄ -aldehyde from B-ionone can be prepared by several successive steps: S.Ishikawa, T.Matsuura,C. 1937, 11.3452, Hsilbron and epol O.Cham.Soc. 1942, 729,1946,1520, Inhoffen et al. Ann. 561, 25, 1948, Milas and epol. O.An.Chem.Soc.70, 1584,1948,Swiss.Pat.255 097, 260 481, Islsr and Epol. Hslv. Chin.Acta 30,1911,1947, Angl.pat.870 310, Ča. pat 167 108. The disadvantage of the mentioned pots is the energy requirement when maintaining the temperature regime at -15 °C, reap. difficult regeneration of used solvents such as pyridine, dimethylformamide and acetonitrile. Conditions of interphase catalysis and used in the procedures for the preparation of C^^-aldshyde from B-ionone and trimethylsulfonium salt: M. Rosenberger, US.pat. 3,998,856, H. Rosenberger, US. pst 4 044 028. The disadvantage of the mentioned poetups is in the first case the complicated preparation of trinetylulfonyl salt, or in the second case, it was necessary to work in anhydrous dimethylsulfoxide with sodium hydride as a base.

The aforementioned shortcomings are eliminated by the method of preparation of C^ ₄ -aldehyde according to the present invention, where, without the need for low temperatures, it is prepared from diethyl sulfate and diethyl sulfide in dichlorostane trinetyl sulfonium netyl sulfide and to the sulfonium oil prepared in this way, B-ionone, non-phase catalyst / benzyltristylanonium chloride, tetra-n-butylammonium chloride or hydrogen sulfate, or other catalyst/ and solid potassium hydroxide. The resulting dichlorstane solution of epoxide II ea ionizes to C^ ₄ -aldehyde in the presence of an aqueous-alcoholic solution of potassium or sodium hydroxide.

The advantage of the invention is further clarified by examples of embodiment without limiting aa to them.

Example 1

200 ml of dichloromethane, 74 ml of dimethyl sulphide and 94 ml of dimethyl sulphate are introduced into a 1500 nl flask equipped with a flask, a thermometer and a reflux condenser. The reaction mixture was stirred for 2 hours so that the temperature did not exceed 32°C. 156 g of 8-ionone, 3.2 g of benzyltriethylammonium at a temperature range of 35 to 40 °C are then added to the ea bank. It is cooled, and the resulting inorganic fraction is filtered off and washed with 100 ml of dichloromethane. Into a 1500 ml flask equipped with a stirrer, add the obtained dichloromethane solution, add 500 ml of methanol or ethanol and 500 ml of a 10% weak aqueous solution of potassium or sodium hydroxide. The contents of the bank are kept at laboratory temperature for 5 hours. The organic layer is separated and the aqueous layer is extracted with 100 ml of dichloromethane; it can be used again after addition of hydroxide. Dichloromethane and dimethyl sulfide are deethylated from the combined dichloromethane extracts after neutralization with dilute sulfuric acid, and they can be used again and for the preparation of the sulfonium salt. The residue is distilled under reduced pressure of 50 to 100 Pa and 140 g of C ₄ -aldehyde with a content of 97% is obtained.

Example 2

Same procedure as Example 1, with the difference that after 8 hours of incubation, the reaction mixture is not filtered, but 800 ml of water is added. After dissolution of the inorganic substrate, the organic layer was separated and the aqueous layer was extracted with 100 ml of dichloromethane. The further procedure is identical to example 1.

Claims (1)

p R e d μέ: τ'· V: Υ Ν- Á. L E Z U . Method for preparing 2-methyl-4-[2^6''6''-triethyl-1-cyclohexenyl]-buten-2-yl]-1-yl. in the medium of dichloroethane in the presence of non-phase catalysts of the general formula /R/ _3NX , where R-ethyl, ethyl, propyl and butyl, R^-ethyl, ethyl, propyl, butyl,., benzyllauryl, X-Cl, Br, HSO^ OH from 4-/2,'6f6'-tri»ethyl-1-cyclohexanyl/-3-buten-2-one, characterized by ea by allowing triethylsulfonium and ethylairane to react in the presence of solid potassium hydroxide or sodium hydroxide with 4-[2,''6 ₁ *6*-trimethyl-1-cyclohexenyl]-3-buten-2-one at /R,S/-/E/-2-ethyl-4-(2-trimethyl-1-cyclohexenyl)-1,2-epoxy3-butene, 2-ethyl-4-[2'6^6*-triaethyl-1-cyclohexenyl]-buten-2-alu-1 is isomerized using an aqueous-ethanolic or ethanolic solution of potassium or sodium hydroxide.