RU1536783C - Method of 3beta- chloro -24r- ethylcholest -5- electronic -4beta -ol synthesis - Google Patents

Abstract

The invention relates to polycyclic alcohols, in particular the preparation of 30 - chloro-24P-ethypostol-5-en-4E - ol - an intermediate for the synthesis of 33 - chloro-40 -oxy-24P-ethyl-cholestan-in-one, which has a high phyto-regulating activity. The aim is to simplify the process. The latter is treated by treating the raw phytosterol with chloroform to separate solid soaps by filtration. Then, thionyl chloride was added to the sterol solution, held for 1 hour, filtered and evaporated. The resulting residue was oxidized with selenium dioxide in dioxane under reflux, followed by evaporation, filtration and chromatographic purification. These conditions make it possible to obtain the target product without isolation of intermediates, which simplifies the process and increases the yield of the target product by 6 times (up to 19%).

Description

The invention relates to the improvement of β-chloro-24P-ethylcholest-5-ene-4 ft -ol by forming a method for preparing the known 3 ft I

which is an intermediate in the synthesis of 3 ft-chloro-4 ft -oxy-24I-ethyl-5 ft cholestan-6-one (II). Compound II has a high phytoregulatory activity.

The purpose of the invention is to simplify the process of producing 3 ft-chloro-24I-ethylcholest-5-en-4 ft -ol (I) from crude phytosterol and increase its yield.

The goal is achieved by a method in which the raw phytosterol is treated with chloroform, the precipitated solid soaps are separated by filtration. Thionyl chloride is directly added to the chloroform solution, which contains a mixture of sterols. The resulting reaction product mixture, which contains 3 ft-chloro-24P-ethylcholest-5-ene, after decomposition of the excess thionyl chloride and evaporation of chloroform, is dissolved in dioxane and the allyl oxidation reaction of selenium dioxide is carried out. The desired product is isolated by chromatographic purification of the reaction mixture. The total yield of 3 ft chloro-24P-ethylcholest-5-en-4 ft-ol from crude phytosterol is 19%.

Example. Raw phytosterol (50 g; 120.5 mmol) was dissolved in 400 ml of chloroform and filtered through silica gel. 12 ml (164.9 mmol) of thionyl chloride were added to the filtrate. The reaction mixture was kept at room temperature for 1 h, filtered through silica gel and alumina. The filtrate was evaporated in vacuo. The residue was dissolved in hexane. filter

5

0

Q

fifty

5

Cl l about and

through silica gel. The filtrate was evaporated in vacuo.

The residue was dissolved in 450 ml of dioxane and 8.5 g (76.6 mmol) of selenium dioxide were added. The reaction mixture was boiled for 6.5 hours, the dioxane was evaporated in vacuo. The residue was dissolved in hexane, filtered through alumina. The filtrate was evaporated in vacuo and the residue was subjected to silica gel column chromatography, eluting with a mixture of hexane and ether (50: 1). 10.3 g (22.9 mmol, 19% yield) of 3 ft chloro-24P-ethyl cholest-5-en-4 ft-ol (1) are obtained, which are identical to the known sample, which has a melting point of 99-102 ° C (GK).

IR spectrum (UR-20, KBr, cm 1): 3565 (OH).

PMR spectrum (Bruker WM-360, 360 MHz, CDCI3, b, ppm): 0.680 (S. ZN, 21-Me). 0.840 CT.J, 7.7 Hz, 6H. 26th and 27th Me). 0.848 (TJ 7.7 Hz, ЗН, 29-Ме), 4.027 (m, 1Н, Сз-НО), 4.207 (g, J. 2.4 Hz, С4-На), 5.720 (m, 1Н. Sat-N )

Thus, the method allows to obtain 3 ft-chloro-24Rch-ethyl cholest-5-en-4 ft-on from raw phytosterol without isolation of intermediate products, purified phytosterol D-sitosterol, 3/3-chloro-24Рх-ethyl cholest-5 -en, in comparison with the prototype to increase the yield of the target product by more than 6 times, and greatly simplify the process of its production.

(56) Copyright certificate of the USSR No. 1356428, cl. C 07 J 9/00, 1986.

USSR copyright certificate No. 1371003, cl. C 07 J 9/00, 1986.