DE893949C - Process for the production of aliphatic urea derivatives - Google Patents

Description

Process for the preparation of aliphatic urea derivatives It is known that hydrogenated, heterocyclic compounds can be split into aliphatic compounds. So z. B. Tetrahydrofurylalkanes of the general formula According to Paul and Smorgonski, split by hydrohalic acids, acid chlorides and acid anhydrides above zgo ° with the formation of derivatives of r, 4-butanediol. It is also known that this splitting is made more difficult if polar groups in R, such as e.g. B. OH, COOH or COOR, are included (R- = CH, C, H5, etc.).

It has now been found that with carbamic acid chloride it is possible to split α-substituted tetrahydrofurans into aliphatic urea derivatives even under the mildest conditions, for example at temperatures below 60 °. Thus, after a few hours, compounds of the following constitution are obtained from α-tetrahydrofurylpropionic acid ester by reaction with r to 2 moles of carbamic acid chloride already at 0 ° and where RII: CO-NH-CO-NH2 or CO-NH-CO-NH-CO-NH2 or CO-NH-CO-NH-CO-NH-CO-NH2, since the carbamic acid residue tends to polymerize easily, with the chlorine in the carbamic acid chloride is easily replaced by another carbamic acid residue, and RM: CH " , CZHs, etc. can be.

When carbamic acid chloride acts on tetrahydrofuryl alcohols, compounds of the general constitution are formed and Polar substituent groups, such as 0 H or C 0 0 H, also react with carbamic acid chloride.

The implementation of the heterocycles is expediently carried out with a Excess of. = up to 2 141o1 carbamic acid chloride at temperatures below 60 °. It can be carried out with and without a solvent, the solvent depends on the solubility of the corresponding starting materials. The reaction is generally over after 2 to 3 hours. However, if you work at temperatures o °, it is then expedient to increase the reaction time to between 2 and 24 hours.

The reaction mass obtained is worked up, for. B. by Entering the same in cold water and recrystallizing the precipitated Product made from boiling water, optionally with the addition of alcohol. The received Products can be used as a raw material for the preparation of resins, which are part can be deformed into threads and films.

EXAMPLE x 20 parts by weight of freshly prepared carbamic acid chloride are introduced dropwise into 18 parts by weight of ice-cold ethyl α-tetrahydrofurylpropionate, with the evolution of hydrogen chloride. After the addition has ended, the cooling is interrupted, as a result of which the temperature of the reaction mixture rises to about 30 ° and the evolution of hydrogen chloride becomes livelier. The temperature is always kept below 30 ° by occasional cooling. After 2 to 3 hours, the mixture solidifies to a pale pink colored pulpy mass. The reaction product is introduced into cold water; a white, flaky product separates out which, after being separated off by filtration, is recrystallized several times - water. The crystalline, white product obtained melts at z52 °. The product has the empirical formula C, 1 H "O5N, Cl; the structural formula for this compound should be as follows: EXAMPLE 2 40 parts by weight of carbamic acid chloride are added dropwise to 17 parts by weight of α-tetrahydrofuryl alcohol while cooling with ice, the reaction solution starting to evolve vigorously with red-violet coloration. When the dropwise addition has ended, the reaction mixture has solidified in crystalline form and is digested with cold water, filtered off and recrystallized several times from water. The substance obtained melts at 1g5 ° and has a sum formula of C9 H15 O 8N4 Cl. The following should be considered as the structural formula

Claims (1)

PATENT CLAIM: Process for the production of aliphatic urea derivatives from α-substituted tetrahydrofuran derivatives, characterized in that these are reacted with one or more moles of carbamic acid chloride at low temperatures.