SU1567565A1 - Method of obtaining 1-chlor-4-methylpentan 2-ol - Google Patents

Abstract

The invention relates to the production of alcohols, in particular the preparation of 1-chloro-4-methylpentan-2-ol, used in the synthesis of ipsenol — an aggregation ferromone of bark beetles and sapwood. The goal is to increase the yield of the target product and simplify the process. The latter will be exhausted with reakia in the medium of epichlorohydrin ether with isopropyl magnesium bromide in the presence of copper acetylacetonate at a molar ratio of 1: 10.5: (0.015 - 0.025), and copper acetylacetonate is used in a mixture with epichlorohydrin and at first the process is carried out at (-40) ° C, and then heated with stirring to room temperature. These conditions increase the yield of the target product from 35 to 75-85% using a smaller (30-40 times) amount of copper salt, which simplifies the processing and recovery of the target product and reduces the amount of waste. 2 tab.

Description

The invention relates to chlorine-containing aliphatic alcohols, in particular, to an improved method for the preparation of 1-chloro-4-methyl-pentan-2-ol used in the synthesis of ipsenol (2-methyl-6-methylenoect-7-en-4-ol a) aggregative ferromone of bark beetles and sapards.

The purpose of the invention is to increase the yield of the target product and simplify the process achieved by using another catalyst, copper acetylacetonate and processing a mixture consisting of epichlorohydrin and copper acetylacetonate, isopropyl magnesium bromide at a molar ratio of 1: 0.015-0.025: 1.05, respectively,

at -40 ° C, in the medium of ether, followed by heating the reaction mass to room temperature with stirring.

Example 1. A 0.1 L glass reactor mounted on a magnetic stirrer in an argon flow was charged with 0.13 g (0.0005 mol) of copper acetylacetonate Cu (CSH702) 2, 5 ml of ether, 1.85 g ( 0.02 mol) of epichlorohydrin and at -40 ° C for 10 minutes, 21 ml of a 0.1 M solution of isopropyl magnesium bromide (0.021 mol) are poured, and heated to 20 ° C for 1 hour with vigorous stirring. At the end of the reaction with l. About With the reaction mixture is decomposed with 5% HC1, organic

cl

ABOUT

1 cl

about cl

the layer is treated, the solvent is removed and the residue is distilled. 2.35 g (85%) of 1-chloro-4-methylpentan-2-ol (I) are obtained. Bp 69 ° C (I mm Hg), pЈ ° 1.4517.

IR (E,): 575; 1050; 1070; 1225; 1280; 1295; 1370; 1390; 1430; 1470; 2878; 2960; 3590. PMR spectrum (8 ppm: 0.86 and 0.95 d (1-6.6 Hz, 6H СН}); 1.3 m (2Н СЧг); 1.84 m (1Н, СН ); 3.3-3.7 m (2H CH2); 3.81 m (1H, CH). M 136. The NMR C spectrum is shown in Table 1.

Found,%: C 53.00; H 11.85; C1 25.94

Calculated,%: C 52.75; H 9.52; O 11.72; C1 26.01

Examples 2-7. Carried out as in Example 1, but either the amount of copper acetyl acetonate or the reaction time is changed.

The results are summarized in table. 2

Try on Carried out as in Example 1, but in reverse order of addition of the reagents: epichlorohydrin and Cu (C5HTO) g are added to isopropylmagnesium bromide. The yield of the target product drops to 35%.

The results are given in table. 2

PRI me R 9. The method is carried out according to a known method, but 5 mol.% CigCl 2 is used and the order of addition of the reagents is changed. The yield of the product is 0.41 g (15%).

0

five

0

five

Example 10 The method is carried out according to a known method, but the order of addition of the reagents is changed. SigC12 is taken in an amount of 0.02 mol%, i.e. in equimolar quantities. The yield of the target product 0,81 g (30%).

The proposed method allows to increase the yield of the target alcohol to 75-85% (versus 35% in the well-known) when using copper salts in a catalytic amount (30-40 times less than in the known method), which simplifies the processing and isolation of the target product, and also reduces waste.

Claims (1)

Invention Formula The method of obtaining 1-chloro-4-methyl-pentan-2-ol from epichlorohydrin and isopropyl magnesium bromide in the presence of a copper salt in ether medium at -40 ° C, followed by heating the reaction mixture with stirring to room temperature, characterized in yield of the target product and simplification of the process, copper acetylacetonate and a mixture consisting of epichlorohydrin and copper acetylacetonate are used as copper salts are treated with isopropyl magnesium bromide at their molar ratio of 1: 0.015-0.025: 1.05, respectively. Table 1 Compound with | cz J s, c4 | c5 I sat 50.54 69.65 43.26 24.58 23.2822.02 tdtdkk 1.5 1.5 1.5 1.5 2.5 2.0 1.5 3.0 table 2 2.35 2, 18 2.07 2.21 85 79 75 80 Note: In all experiments, the temperature mode is maintained as in Example I, the ratio of isopropyl magnesium bromide to epichlorohydrin is 1.05: 1.0 (0.021 mol: 0.020 mol), the solvent is sulfur ether, the yield of the desired product is calculated on epichlorohydrin; in Example 8, the reagent order is added.