DE1134381B - Process for the preparation of 4, 5, 5-trisubstituted oxazolidones- (2) - Google Patents

Description

Process for the preparation of 4,5,5-trisubstituted oxazolidone- (2) It is known that oxazolidones (2) substituted in the 4 and 5-positions from corresponding α-Amino alcohols and carbonic acid esters can be obtained. In the preparation of of oxazolidones, which are simultaneously single in the 4-position and double in the 5-position are substituted, the process is not suitable for technical implementation, because the a-amino alcohols with a tertiary hydroxyl group required as starting material are difficult to access.

It has been found that 4,5,5-trisubstituted oxazolidones- (2) of the general formula where R1 and R2 are identical or different aliphatic, cycloaliphatic, araliphatic or aromatic radicals or together are members of a cycloaliphatic ring and R3 is a hydrogen atom or an aliphatic, cycloaliphatic, araliphatic or aromatic radical is obtained when substituted dioxolanones of the general formula wherein R1 to R3 have the same meaning as above, reacted with formamide at elevated temperature until an equivalent amount of carbon dioxide has been evolved.

The process can be represented by the following reaction equation: The substituted dioxolanones used as starting materials are z. B. easily accessible by adding carbon dioxide to corresponding tertiary acetylene alcohols.

For example, you can use: 4-methylene-5, 5-dimethyl-dioxolanone- (2) 4-methylene-5-methyl-5-ethyl-dioxolanone- (2) 4-methylene-5-methyl-5-propyl-dioxolanone- (2) 4-methylene-5-methyl-5-isobutyl-dioxolanone- (2) 4-methylene-5-methyl-5-n-butyl-dioxolanone- (2) 4-methylene-5, 5-dibutyl-dioxolanone- (2) 4-methylene-5-methyl- [4 ', 8', 12'-trimethyltridecanyl- (I. ,) 1-dioxolanone- (2) 4-methylene-5, 5-pentamethylene-dioxolanone- (2) 4-methylene-5-methyl-5-phenyl-dioxolanone- (2) 4-methylene-5-methyl-5-cyclohexyldioxolanone- (2) 4-ethylidene-5-methyl-5-cyclohexyldioxolanone- (2) 4-ethylidene-5,5-pentamethylene-dioxolanone- (2) 4-benzylidene-5,5-dimethyl-dioxolanone- (2) 4-nonylidene-5,5-dimethyl-dioxolanone- (2) .

The reaction is carried out so that the dioxolanones with a Heat excess of anhydrous formamide for a while, for example to 150 to 220 ° C, the progress of the reaction being measured by measuring the amount developed Carbon dioxide can be conveniently tracked. The heating is stopped after development molar amounts of carbon dioxide. The reaction mixtures are worked up by Distillation or after the excess formamide has been distilled off by crystallization.

4,5,5-trisubstituted oxazolidones- (2) can be used as plant growth regulators use. The compounds prepared according to the invention can also be used as fuel additives be used. They are also valuable intermediate products for manufacture of polymerizable monomers, in which they z. B. converted by vinylation can be.

In the following examples, parts mean unless otherwise indicated, parts by weight.

Parts by weight and parts by volume are in relation to one another like grams to liters.

Example 1 256 parts of 4-methylene-5,5-dimethyl-dioxolanone- (2) and 600 Parts of formamide are heated to the boil under gentle reflux. The escaping Carbon dioxide is measured using a gas meter.

When 50 parts by volume of gas have evolved, heating is interrupted and the reaction mixture is distilled under reduced pressure. One obtains 486 parts of unchanged formamide at a boiling point of 96 to 103 ° C / 10 Torr. Then go at 114 to 119 ° C / 0.1 Torr 186 parts of 4,5,5-trimethyl-oxazolidone- (2) above. The compound solidifies in the template and melts after recrystallization from ether / petroleum ether at 60 to 62 "C.

Example 2 284 parts of 4-methylene-5-methyl-5-ethyl-dioxo lanone- (2) (Bp. 78 to 80 "C / 9 Torr, n205 1.4355) and 600 parts of formamide are in the weak Kept boiling. As soon as you have 50 parts by volume with a gas meter connected to the cooler has measured, the reaction is terminated. When the mixture is distilled In addition to 475 parts of formamide, 197 parts are obtained at 129 ° to 130 ° C./0.3 torr boiling fraction, which consists of 4,5-dimethyl-5-äthyloxazolidon- (2). The connection is liquid and has a refractive index of n2D5 1.4618.

Example 3 170 parts of 4-methylene-5-methyl-5-isobutyl-dioxolanone- (2) (Bp 94 to 96 "C / 8 Torr, n2D6 1.4403) and 250 parts of formamide are so long on Heated 180 to 1850 C until 25 parts by volume of carbon dioxide have split off. at the distillation of the reaction mixture gives 179 parts of formamide and 104 parts 4,5-dimethyl-5-isobutyl-oxazolidone- (2) was obtained. The latter goes at 139 to 146 ° C / 0.1 Torr and solidifies in the original. The connection has after recrystallization from petroleum ether has a melting point of 39 to 410 C.

Example 4 168 parts of 4-methylene-5,5-pentamethylene-dioxo-Ianon- (2) and 300 parts of formamide are heated to 185 to 1900 C. After developing 25 Parts by volume of carbon dioxide, the heating is stopped and the reaction mixture is distilled. 224 parts of unchanged formamide and 133 parts of 4-methyl-5,5-pentamethylene-oxazolidone- (2) are obtained with a boiling range of - 155 to 1670 CIO, 1 Torr. The connection will be established soon crystalline and, after recrystallization from ethyl acetate, melts at 110 to 111 "C.

Example 5 196 parts of 4-methylene-5,5-heptamethylene-dioxolanone- (2) (Bp. 108 ° C / 0.25 Torr, n205 1.4906) and 300 parts of formamide are brought to the boil heated to a gentle reflux. After the development of 25 parts by value carbon dioxide becomes the reaction stopped and the excess formamide under reduced pressure distilled off. The residue begins to crystallize after standing for several days.

After trituration with ether and suction filtration, 111 parts of 4-methyl-5,5-heptamethylene-oxazolidone- (2) are obtained.

The compound melts after recrystallization from ethyl acetate 100 to l0l0C.

Claims (1)

PATENT CLAIM: Process for the preparation of 4,5,5-trisubstituted Oxazolidonen- (2) of the general formula where R1 and R2 are identical or different aliphatic, cycloaliphatic, aromatic or araliphatic radicals or together are members of a cycloaliphatic ring and R3 is a hydrogen atom or an aliphatic, cycloaliphatic, araliphatic or aromatic radical, characterized in that one dioxolanones of the general formula wherein R1 to R3 have the same meaning as above, reacted with formamide at elevated temperature until an equivalent amount of carbon dioxide has been evolved.