SU411086A1 - - Google Patents

Description

one

This invention relates to a new process for the preparation of 2,2,4,4-tetrasubstituted dioxanes 1, 3 of formula I

R-i

V °

.

where RI and R2-alkyl, aryl or Ri and R2 together is alkylene;

RS is alkyl or aryl,

R4-alkyl, alkoxyalkyl or oxyalkyl, which are AID products in the synthesis of a number of compounds.

A known method for producing substituted dioxans-1, 3 by reacting diols-1,3 with aldehydes when heated in an organic solvent medium in the presence of an acidic catalyst. The starting compounds are not readily available.

The purpose of the invention is to simplify the process technology.

According to the invention, 2,2,4,4-tetra-substituted dioxanes-1,3 of formula I are obtained by the interaction of 2,2,4-trisubstituted dioxanes 1, 3 of formula II

P

I,

,; i -R.-.

where Ri, Ra and Rs have the indicated meanings, with an alkene, alkoxyalken or aldehyde

accordingly, when heated in the presence of a radical replacement initiator. The interaction can be carried out in the environment of the solvent or without it at a temperature of from 50 to 200 ° C.

Organic peroxides, hydroperoxides, dpaso-deposition of penny, or light radiation can be used as the initiator of radical substitution reactions. Example 1. Getting 2,2-pentamethyla-4methyl-4-nonnildioxan-1, 3

A mixture of 170 g of 2,2-peptamethylene-4-methyldioxia-1, 3, 1.5 g of di-pret-butyl peroxide and 12.6 g of nonene-1 (molar ratio of reagents 10: 0.1: 1) is stirred at 140 ° C for

18 h and then distilled in vacuo.

This gives 27.1 g (yield 91%) 2,2-peitamethyl-4-methyl-4-nonyldioxa 11a-1, 3 with mt bale. 118-12PC (3 mmHg), according to 1.4684, df 0.9346. The IR spectrum contains intense absorption bands in the region of 1180-1040, characteristic of the 1,3-dioxane structure. The presence of the 1,3-dioxap ring in the isolated compound was also proved by the formation of methylal and methanolysis. Example 2. Preparation of 2,2-pentamethylene-4 .methyl-4-octyldioxane-1,3. A mixture of 170 g of 2,2-pentamethylene-4-methyldioxane-1, 3, 1.7 g of azodiisobutyroitrile and 11.2. g of octene-1 (molar ratio of reagents 10: 0.1: 1) is stirred at 65 ° C for 48 hours and then distilled in vacuo. Obtain 24 g (yield 85%) 2,2-pentamethylene-4methyl-4-octyldioxane-1, 3 with t. Kip. 109-111 ° С (3 mm of mercury), according to 1.4628; df 0.9348. Example 3. Preparation of 2,2-pentamethylene-4methyl-4-methoxypropyl dioxaia-1, 3 A mixture of 170 g of 2,2-pentamethylene-4-methyldioxane-1, 3, 1.5 g of di-gret-butyl peroxide and 7.2 g allyl methyl ether (molar ratio of reagents 10: 0.1: 1) is stirred at 140 ° C for 18 hours and then distilled in vacuo. Obtain 12.8 g (yield 90%) 2,2-pentamethylene-4-methyl-4 - methoxypropyl dioxane-1, 3 with t. Kip. 112-114 ° C (3 mm Hg. Art.), At 1.4712. Example 4. Getting 2,2-pentamethylene-4methyl-4-ethok € ipropyldioxap-1, 3. Prepared analogously to number 3 from 2,2-pentamethylene-4-methyldioxane-1, 3 and allyl ethyl ether. The yield of 74.5%, so kin. 192-193 ° C (3 mm Hg. Art.). 1.4735 each. Example 5. Obtaining 2,2-pentamethylene-4methyl-4-hydroxymethyldioxane-1, 3. A mixture of 170 g of 2,2-pentamethylene-4-methyldioxane-1, 3, 1.5 g of di-g / er-butyl peroxide, n 3 g of paraformaldehyde (molar ratio of reagents 10: 0.1: 1) is stirred at 18 hour then distilled in vacuo. Get 16.2 g (yield 8i%) 2,2-pentamethylene-4-methyl - 4-oxymethyldioxane - 1.3 with T. KIP. 151 -153 ° C (14 mm Hg. Art.), Pb 1.4686: df 1.034. In I1-snektre there are intense. foot, in the region of 1180–950 cm, characteristic of the G, 3-dioxai cycle, and a broad band with a maximum at 3320, due to vibrations of the hydroxyl group. Cyclohexanone and triol are obtained by hydrolysis. Subject of the invention 1. Method for the preparation of 2,2,4,4-tetra-substituted dioxanes-1,3 of the formula I 00 h i: i Cr-2 where RI and Cg are alkyl, aryl or Ri and R2 together is alkylene; Ra is alkyl or aryl; R4 is alkyl, alkoxyalkyl or hydroxyalkyl, characterized in that, in order to simplify the process of the process, 2,2,4-trisubstituted dioxane-1,3 of formula II, where RI, Rs and Ra have the indicated values, They are reacted with an alkene, alkoxyalkene or aldehyde, respectively, when heated in the presence of an initiator of reactions of radical substitution. 2. A method according to claim 1, characterized in that the reaction is carried out in a solvent medium. 3. A method according to claim 1, characterized in that the reaction is carried out at a temperature of 50-200 ° C.