US3129215A

US3129215A - Certain 1, 2-diazetidines and their preparation

Info

Publication number: US3129215A
Application number: US735099A
Authority: US
Inventors: Horvitz David
Original assignee: FMC Corp
Current assignee: FMC Corp
Priority date: 1958-05-14
Filing date: 1958-05-14
Publication date: 1964-04-14
Anticipated expiration: 1981-04-14

Description

United States Patent 3,129,215 CERTAIN 1,2-DIAZETIDINES AND THEIR PREPARATION David Horvitz, Cheverly, Mi, assignor, by mesne assignments, to FMC Corporation, New York, N.Y., a corporation of Delaware No Drawing. Filed May 14, 1958, Ser. No. 735,099 12 Claims. (Cl. 260-439) This invention relates to a new class of organic chemical compounds and a method for producing the same. More particularly, the compounds of the invention are alkyl substituted diazetidines derived from dialkyl substituted hydrazines.

The compounds of this invention are 1,2-alkyl diazetidines as represented by the following structural formula:

wherein R is a lower alkyl group having from 1 to 4 carbon atoms, and R and R", which may be either the same or different, are hydrogen or an alkyl group having from 1 to 4 carbon atoms. The Rs also may be the same or different. The preferred compound of the invention is 1,2-dimethyl-diazetidine, having the following structural formula:

These new compounds are useful as rocket fuels or rocket fuel additives. Particularly outstanding in this respect are 1,2-dimethyldiazetidine and 1,2-diethyldiazetidine. Their usefulness for this purpose is due to the peculiar structure of the compounds. They are highly endothermic because of the nitrogen to nitrogen bonds and the strained four-membered ring. Consequently, a high specific impulse is obtained when these compounds are used with any of the oxidizers commonly employed in rocket propulsion such as nitric acid, oxygen, etc. It has also been determined that these compounds are hypergolic with white fuming nitric acid and, therefore, offer further advantages as rocket fuels. The low freezing points of these compounds, e.g. 91.6 to --88.8 C. for 1,2-dimethyldiazetidine, is another important factor in determining their suitability for such uses.

In accordance with the present invention, it has been found that 1,2-dialkyldiazetidines may be prepared from the reaction between dialkyl substituted hydrazines and organic dihalides. The reaction may be operated at room temperature, though reaction rates and yields are increased by utilizing higher temperatures up to a maximum of about 150 C. The preferred temperature range is, however, about 50 to 100 C.

The 1,2-dialkyl substituted hydrazines useful for the present purposes will correspond to the following structural formula:

RHN-NHR wherein the Rs are alkyl groups having from about 1 to 4, preferably about 1 to 2, carbon atoms. The Rs may be the same or different. Examples of both straight chain 3,129,215 Patented Apr. 14, 1964 ice and branch chain dialkyl substituted hydrazines which can be utilized include:

ROH-CHR" wherein R and R" are either hydrogen or alkyl groups having from about 1 to 4 carbon atoms while the halogen substituents are indicated by X. It will also be understood that R and R" may either be the same or different. The halogen substituents may be chlorides, bromides, and iodides. In accordance with the preferred features of the invention, the chlorides and bromides are preferred, since the use of iodides results in the formation of undesirable polymeric material. Specific examples of dihalides useful in this process include:

Ethylene dichloride Ethylene dibromide 1,2-dichloro-3-methylpropane 1,2-propylene dibromide 1,2-butylene dichloride 2,3-butylene dibromide 1,2-hexylene dibromide, etc.

In general, it is preferred to carry out the reaction between the organic dihalide and the dialkyl substituted hydrazine in an inert reaction medium. Conventional reaction media may be employed, though such organic compounds as aromatic hydrocarbons, aliphatic hydrocarbons, aralkyl hydrocarbon, cycloalkanes, ethers, alcohols, etc. have been found to be particularly useful. Specific examples of operable reaction media include pentane, hexane, cyclohexane, benzene, toluene, naphthalene, diethyl ether, dibutyl ether, ethyl alcohol, butyl alcohol and the like. The reaction medium serves to dissolve the reactants and to prevent undesirable polymerization side reactions from taking place. The ratio of the reaction medium to reactants may be within the range of about 5:1 to 50:1, preferably about 10 parts of the solvent to 1 part of the reactants.

In order to neutralize the acidic by-products of the reactions taking place in the process, it is desirable to have an alkaline reagent present in the reaction mixture. A stoichiometric excess of the dialkyl substituted hydrazines may be employed for this purpose, though such use tends to increase side reactions. It has also been found that strong bases such as sodium hydroxide and potassium hydroxide are also unsuitable, since they dehalogenate the organic dihalide reactant thereby reducing the yield and increasing the quantities of undesirable by-products. The use of mild alkaline reagents is, therefore, preferred. Such reagents are, for example, the alkali metal and alkaline earth metal carbonates. Illustrative compounds are sodium carbonate, potassium carbonate, calcium carbonate, barium carbonate, etc. The amount of alkaline reagent employed may vary over a wide range, though only that amount sufiicient to substantially neutralize the acid by-products need be employed.

In accordance with another feature of the invention, it has been found essential to control carefully the relative proportions of reactants employed. The highest yields are obtained when utilizing substantially stoichiometric amounts of the organic dihalide and the dialkyl substituted hydrazine. As previously noted, the use of an excess of the hydrazine derivative results in the formation of certain polymerization products. More specifically, when the mol ratio of the alkyl substituted hydrazine to the organic dihalide' becomes appreciably greater than one with a high concentration of reactants in solution, the yield of the diazetidine derivatives becomes quite small and the major product is a compound corresponding to the following structural formula:

wherein R, R and R are as previously defined. It will be understood that such compounds will usually be formed in minor proportions even when carrying out the reaction under the most favorable conditions for the production of the diazetidine derivatives. If the preparation of a major amount of hydrazinotype compounds is desired, the useof excess disubstituted'hydrazine reactants will be employed; These compounds are also novel and, similarly to the diazetidine compounds, they may be used as a rocket propellant in conjunction with the common oxidizers listed above.

The invention will be more fully understood by reference to thefollowin'g specific embodiment.

Example A solution of 30 parts of symmetrical dimethylhydrazine and 135 parts of sodium carbonate in 290 parts of xylene was heated to 100 C. with mechanical agitation. To this mixture was added a solution of 94 parts of ethylene dibromide in 90 parts of xylene. The resulting reaction mixture was distiiled, and the recovered distillate separated into two layers. The top layer formed the bulk of the distillate, while the bottom layer amounted to only about 15 parts.

The top layer was fractionally distilled and 1,2- dimethyldiazetidine recovered therefrom. The molecular weight of the dimethyld-iazet-idine so recovered was 89 (theoretical value is 86.14) as determined by freezing point depression in benzene. A test with methylmagnesium iodide showed the absence of any active hydrogen. This test confirmed the structure of the compound as being:

CH3N'N-CH3 HgCCHz and eliminated the possibility of the compound being 1- methyl-l-vinyl-Q-methyl hydrazine:

oH NHN-H CH=OH1 LZ-dimethyldiazeticline is a colorless liquid boiling at 70.2-70.4" 0/7 60 mm. It freezes at 9l.6 to 8'8.8 C. The density was determined to be 0.8099 gm./liter at 25 C., and the index of refraction was n =1.4130. Molecular refraction was determined as 26.52 as compared to the calculated value of 26.40. Elementary analysis for carbon, hydrogen and nitrogen gave the following figures:

4 The bottom layer contained 1,2-bis-(N,N'-dimethylhydrazino) ethane:

The novel compound, 1,2-dimethy1diazetidine, may also be employed to form plastic materials by polymerination with conventional acid catalysts. Thus, linear polymers of the form (N-N-CHzOHzN-NCH2OH) 1 CH3 CH3 CH5 CH3 are produced. The higher, dialkyl diazetidines are also useful in the preparation of polymers. It is possible, therefore,to obtain a variety of new polymers from the novel diazetidine compounds of this invention. The novel 1,2-bis-( N,N' dialkylhydrazine)alkylene com pounds may be also employed as monomers in the preparationof novel nitrogen-containing polymers.

While a particular embodiment of this invention is shown above, it willbe understood that the invention is obvious subject to various modifications without departing from its broader aspects.

What is claimed is:

1. A compound having the formula:

RHJJ-C'EHR" wherein R is a lower alkyl radical, and R and R" are selected from the group consisting of hydrogen and a lower alkyl radical.

2. The compound of claim 1 wherein R is an alkyl radical having from 1 to 4 carbon atoms.

3. The compound of claim 1 wherein R and R" are hydrogen.

4. 1,2-dimethyldiazetidine.

5. A process which comprises reacting a lower dialkyl substituted hydrazine and-a lower. alkyl vicinal dihalide in a mol'ratio of said dialk-yl substituted hydrazine to said alkyl dihalide of about 1 to 1 in the presence of an inert reaction medium and a mild alkaline reagent other than said' dialkyl substituted hydrazine at a temperature rangingfrom room temperature up to about 150 C. to produce, a reaction mixture containing at least one chemical compound having the formula:

R'HCCHR" wherein. R is a lower alkyl radical and R and R are selected from the group consisting of hydrogen and a lower alkyl radical.

6. The process of claim 5 wherein said alkyl substituted hydrazine has the structural formula:

wherein R is an alkyl group having from 1 to 4 carbon atoms.

7-. The process of claim 5 wherein said alkyl halide has the structural formula:

wherein R and R" are selected from the groupconsis-ting of hydrogen and a lower alkyl halide, and X is a halide.

8. The process of claim 7 wherein R and R are hydrogen.

9. The process of claim 7 wherein X is bromide.

10. The process of claim 5 wherein said reaction temperature is within the range of about 50 to C.

5 6 11. A process which comprises heating about stoioho- -12. The process of claim 11 wherein said alkaline remetnic amounts of dimethylhydrazine and ethylene diagent is sodium carbonate. bromide at a temperature within the range of about 50 References Cited in the file of this patent to 150 C. in the presence of an inert organic reaetion medium and an alkaline reagent selected from the group 5 UNITED A ES PA ENTS consisting of alkali metal and alkaline earth metal carbo- 2 4 5 5 D yf J l 20, 1948 nates to obtain a. reaction mixture containing 1,2-di- 2 55 17 Cramer Dem 14, 1948 methyldiazeti'dine, and separating said LZ-dimethyldi- 2 643 250 s n 1 23 1953 azetidine therefrom 2,802,031 Horvitz Aug, 6, 1957 10

Claims

1. A COMPOUND HAVING THE FORMULA:

5. A PROCESS WHICH COMPRISES REACTING A LOWER DIALKYL SUBSTITUTED HYDRAZINE AND AL OWER ALKYL VICINAL DIHALIDE IN A MOL RATIO OF SAID DIALKYL SUBSTITUTED HYDRAZINE TO SAID ALKYL DIHALIDE OF ABOUT 1 TO 1 IN THE PRESENCE OF AN INERT REACTION MEDIUM AND A MILD ALKALINE REAGENT OTHER THAN SAID DIALKYL SUBSTITUTED HYDROZINE AT A TEMPERATURE RANGING FROM ROOM TEMPERATURE UP TO ABOUT 150*C. TO PRODUCE A REACTION MIXTURE CONTAINING AT LEAST ONE CHEMICAL COMPOUND HAVING THE FORMULA: