Abstract:
Process for preparing 2-oxazolidone and its derivatives by reacting react carbon dioxide with aziridine compound, preferably, in the presence of Lewis acid as a catalyst.

Description:
This is a continuation of application Ser. No. 779,335, filed Mar. 21, 1977, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     2-oxazoidone and its derivatives are represented by the following formula: ##STR1## 
     2-oxazolidone has the following formula: ##STR2## 
     A derivative of 2-oxazolidone such as 4-methyl-2-oxazolidone has the following formula: ##STR3## 
     Such 2-oxazolidone and its derivatives are useful as intermediates in the preparation of drugs, and polymers of 2-oxazolidone derivatives are used, for example, in preparation of fibers, tablet coatings, lubricant additives, cigarette filters, rust inhibitors and dyeing assistants. 
     Many conventional processes for preparing 2-oxazolidone and its derivatives are known. 2-oxazolidone may be prepared by the reaction as shown below: 
     the reaction of β-aminoalcohol with a compound selected from the group consisting of phosgene, dialkylcarbonate, carbon dioxide, urea, isocyanate, ethylchlorocarbonate, carbon disulfide; 
     the reaction of epoxide with a compound selected from the group consisting of cyanuric acid, urea and cyanamide; 
     the reaction of acrolein with isocyanate; or the removal of hydrochloric acid from β-hydroxyalkylsemicarbazide. 
     However, such conventional processes have disadvantages, for example, high cost of starting raw materials, complexity of the procedure or low yield of 2-oxazolidone and its derivatives. 
     It is an object of the present invention to provide a process of preparing 2-oxazolidone and its derivatives at a low cost and a high yield. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a process for preparing 2-oxazolidone and its derivatives. 
     2-oxazolidone and its derivatives have the following general formula: ##STR4## wherein R 1  is hydrogen, a lower alkyl group of 1 to 4 carbon atoms, phenyl and benzyl, and R 2  is hydrogen, a lower alkyl group of 1 to 4 carbon atoms, a substituted lower alkyl group such as β-cyanoethyl, β-aminopropyl, α-hydroxyethyl and β-chloroethyl, unsubstituted or substituted phenyl, benzyl, an acyl group such as formyl, acetyl, propionyl, benzoyl, toluoyl, acryloyl and methacryloyl. 
     The process of the present invention comprises reacting carbon dioxide with an aziridine compound. 
     Aziridine compounds include aziridine and its derivatives represented by the following formula: ##STR5## wherein R 1  and R 2  are as hereinbefore defined. ##STR6## 
     The reaction of carbon dioxide with an aziridine compound may be carried out in a solvent. Such solvents include saturated paraffinic hydrocarbons such as n-heptane, aromatic hydrocarbons such as benzane, substituted aromatic hydrocarbons such as o-dichlorobenzene, cycloparaffins such as cyclohexane, alcohols such as methanol and ethanol, ethers such as diethylether, ketones such as acetone, halogenated hydrocarbons such as chloroform, cyclic esters such as tetrahydrofuran, sulfoxides such as dimethyl sulfoxide, and amides such as formamide. 
     The reaction of the present invention may be carried out at a temperature of 0° C. to 200° C., preferably 20° C. to 120° C., by using a mixture of carbon dioxide and aziridine compound in the molar ratio (CO 2  /aziridines) of 0.1 to 1,000, preferably 1 to 100. 
     The reaction of the present invention may effectively be carried out in the presence of Lewis acid as a catalyst. 
     Preferred Lewis acids used as a catalyst in the present invention include halogens such as chlorine, bromine and iodine, halogenides of titanium, aluminium, manganese, copper, tin, antimony, iron, zinc, phosphorus and boron. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following examples are given by way of illustration only: 
     EXAMPLE 1 
     2.5 l (S.T.P.) of carbon dioxide, 3.2 g of propyleneimine, 75 mg of iodine and 8.0 g of chloroform were placed in a stainless steel high-pressure tube of about 300 ml in volume. After the mixture was allowed to react at a temperature of 30° C. for 31 hours, the reaction product was taken out of the high-pressure tube and distilled under reduced pressure to obtain 2.4 g of pure 4-methyl-2-oxazolidone, which has the properties as shown below: 
     b.p. 128°-130° C. (3 mmHg); n.m.r. (CDCl 3 ) δ 1.3(3H, CH 3 , d), 4.0(1H, CH 2  and 1H, CH, m), 4.5(1H, CH 2 , S) and 6.7(1H, NH, broad); i.r. ν max  1735 and 1240cm -1  ; 
     
         ______________________________________Analysis:        C(%)     H(%)     N(%)______________________________________Found            47.38    7.10     14.35Calculated for C H.sub.2 NO.sub.3            42.81    6.53     13.86______________________________________ 
    
     EXAMPLE 2 
     3 l (S.T.P.) of carbon dioxide, 3.2 g of ethyleneimine, 50 mg of zinc chloride and 20 g of ethanol were placed in a stainless steel high-pressure tube of 300 ml in volume. After the mixture was allowed to react at a temperature of 60° C. for 50 hours, the reaction product was taken out of the high-pressure tube and recrystallized from chloroform solution of the reaction product to obtain 1.5 g of pure 2-oxazolidone, which has the properties as shown below: 
     m.p. 86°-88° C.; n.m.r. (D 2  O) δ 4.14(2H, CH 2 , t), 5.02(2H, CH 2 , t); i.r. ν max  1735, 1256, 1085, 1023, 970 and 920cm -1  ; 
     
         ______________________________________Analysis:        C(%)     H(%)     N(%)______________________________________Found            41.70    5.87     16.11Calculated for C.sub.2 H.sub.4 NO.sub.2            41.38    8.75     16.09______________________________________ 
    
     EXAMPLE 3-7 
     The same procedure as that described in Example 1 was repeated except that the procedure was carried out under the conditions as shown below to obtain pure 4-methyl-2-oxazolidone: 
     
         __________________________________________________________________________Carbon Propylene-             Catalyst    Reaction                                Reaction                                     4-methyl-2-Exampledioxide       imine (Lewis acid)                    Solvent                         temperature                                time oxazolidoneNo.  (l) (S.T.P.)       (g)   (mg)   (g)  (°C.)                                (hcur)                                     (g)__________________________________________________________________________             ferric3    2.4    3.5   chloride                    hexane                         100    50   1.2             50     204    7      4     phosphorus                    acetone                         20     48   3.5             trichloride                    50             505    5      3.2   antimony                    benzene                         75     52   3             tribromide                    60             606    3      3.5   tin tetra-                    --   50     48   1.5             chloride             507    5      4     --     chloro-                         80     50   0.3                    form                    30__________________________________________________________________________ 
    
     EXAMPLE 8-10 
     The same procedure as that described in Example 2 was repeated except that the procedure was carried out under the conditions as shown below to obtain pure 2-oxazolidone: 
     
         __________________________________________________________________________    Carbon     Ethylene-           Catalyst    Reaction                              ReactionSample    dioxide     imine (Lewis acid)                  Solvent                       temperature                              time 2-oxazolidoneNo. (l) (S.T.P.)     (g)   (mg)   (g)  (°C.)                              (hour)                                   (g)__________________________________________________________________________                  methylene           iodine chloride8   10    3     30     80   80     20   1.8           copper tetrahy-           iodide drofuran9   5.5   3.2   80     30   80     73   0.9                  methylene                  chloride10  10    3     --     80   80     50   0.2__________________________________________________________________________ 
    
     EXAMPLE 11-16 
     The same procedure as that described in Example 1 was repeated except that the procedure was carried out in a stainless steel high-pressure tube of about 50 ml under the conditions as shown below to obtain 2-oxazolidone derivatives such as N-(β-cyanoethyl)-2-oxazolidone, 3-acryloyl-2-oxazolidone and 3-phenyl-2-oxazolidone: 
     
         __________________________________________________________________________Carbon      Aziridine             Catalyst         Reaction                                     Reaction                                          2-oxazolidoneExampledioxide      compound             (Lewis acid)                        Solvent                              temperature                                     time derivativeNo.  (l) (S.T.P.)      (g)    (mg)       (g)   (°C.)                                     (hour)                                          (g)__________________________________________________________________________      N-(β-cyano-                    3-(β-cyano-      ethyl)-             ferric                       ethyl)-2-11   3     ethylene-             chloride   n-heptane                              70     24   oxazolidone      imine  30         8                 1.1      1      N-(β-cyano-             antimony   chloroform        3-(βcyano-      ethyl)-                             ethyl)-2-      ethylene-                           oxazolidone      imine12   3     1      trichloride                        10    70     30   1.3             30      N-(β-cyano-             alumium    o-dichloro-       3-(β-cyano-      ethyl)-                             ethyl)-2-      ethylene-                           oxazolidone      imine13   3     1      chloride   benzene                              80     30   0.3             30         5      N-β-cyano-   chloroform                              80     24   3-(βcyano-      ethyl)-                             ethyl)-2-      ethylene-                           oxazollicone      imine14   3     1      --         5                 0.2      N-acryloyl-             iodine     dioxane           3-acryloyl-15   3     ethylene-             60         10    60     30   2-oxazolidone      imine                               2.1      3      N-phenyl-             bromine    tetrahydro-       3-phenyl-16   2     ethylene-             60         furan 60     24   2-oxazolidone      imine             10                1.2      3__________________________________________________________________________