United States Patent Office Patented Feb

3,562,333 United States Patent Office Patented Feb. 9, 1971

1 2 3,562,333 lower alkyl radicals represented by R2, R3 and R4 are FLUORO-ALKYL-SUBSTITUTED POLYNITRO the following: -—CF3, —CH2CF3, —CH2CHF2, AROMATIC AMINES AND NITRAMINES Josef .l. Schmidt-Collerus, Denver, (1010., and Don N. Gray, Towson, Md., assignors to the United States of —CH2CH2CH2CHF3, '—‘CH3, _C2H5, —~C3H8, 01' Oth?r America as represented by the Secretary of the Air 5 monovalent lower alkyl and ?uorine-containing lower Force N0 Drawing. Filed Jan. 28, 1964, Ser. No. 340,837 alkyl radicals either straight chained or branched in Int. Cl. C07c 87/60 structure. U.S. Cl. 260—-577 6 Claims The compounds of this invention represent a new class 10 of explosives; namely, N-?uoro-alkyl and ?uoro-alkyl This invention relates to fluoro-alkyl-substituted poly substituted picramides and nitramines. Typical com nitro aromatic amines and nitramines. More speci?cally, pounds of the invention are conveniently prepared by this invention concerns itself with ?uoro-substituted alkyl nitrating an appropriate substituted trinitroaniline. This group derivatives of picramide (I) and tetryl (II) as represented by the following structural formulas: starting compound is in turn prepared by effecting a re 15 action between an equimolar mixture of a ?uoro-substi IIQH2 OzNN CH3 tuted trinitrobenzene, such as picryl ?uoride; or a chloro substituted trinitrobenzotri?uoride, with ammonia or an appropriate substituted amine. The synthesis schemes dis closed by the following examples produce speci?c com 20 pounds but is also representative of the method for syn thesizing the whole generic group by the judicious choice Ill 0 2 (I) N 0 2 (II) of appropriately substituted starting materials. in which ?uorine is substituted in the N-alkyl group or on The following examples illustrate the new compounds the benzene nucleus of the aromatic ring. The preferred of this invention and the basic synthesis scheme by which compounds of this invention are the tri?uoromethyl sub 25 they are prepared. These examples, however, are by way stituted derivatives of picramide and tetryl. of illustration only and are not to be considered as limit Picramide, tetryl, ethyl tetryl and butyl tetryl are well ing the scope of the invention in any way. known for their use in military munitions as primary ex EXAMPLE 1 plosives, boosters, and detonators. These explosives ex hibit a much higher explosive potential than TNT or 30 To a solution of 52.5 g. (0.17 mole) of 3-chloro-2,4,6 picric acid; but are distinctly more sensitive to shock and trinitrobenzotri?uoride in 250 ml. of benzene in a 1-liter heat. Consequently, their military utility is minimized be separatory funnel was added a solution of 50 ml. of 40% cause of the severe conditions encountered by the military monomethylamine in 150 ml. of distilled water. This mix during ?eld operations. With this invention, however, it ture was shaken and kept cool by holding the funnel under has been found that the undesirable sensitivity charac 35 the water tap. After ten minutes shaking, the solution teristics of the above referred to explosives can be abro was dark red. At this point a solution of 20 g. of sodium gated by providing a new class of ?uoro-alkyl-substituted carbonate in 200 ml. of water was added and again the derivatives of picramide and tetryl. These new compounds, mixture shaken. The benzene layer was removed, and although exhibiting a high explosive potential are dis— evaporated on a steam bath, leaving a bright-yellow solid tinctly more resistant to shock and heat. As a result, they 40 residue. Recrystallization from 95% ethanol gave an are much more useful when employed by the military as 82% yield of 3 - tri?uoromethyl-2,4,6~trinitro-N-methyl primary explosives, detonators, boosters and in other ex aniline; M.P. 137-138° C. plosive applications. Additionally, the compounds of this EXAMPLE 2 invention are useful as dyestuffs in the coloration of 45 Five grams of 3-chloro-2,4,6-trinitrobenzotri?uoride cellulosic textile materials and as intermediates in the was dissolved in 30 ml. of dry methyl alcohol and the production of other novel and useful compounds. solution cooled in an ice bath. Gaseous ammonia was then Accordingly, the primary object of this invention is to bubbled through the solution until a permanent red color provide a new class of explosives Which are characterized was present. The solution was then ?ltered through a hard by a high explosive potential coupled with a high degree 50 ?lter and the alcohol solution was concentrated to one of thermal and shock resistivity. third its volume under reduced pressure to give a dark Another object of this invention is to provide a new red precipitate. This was ?ltered and the ?lter cake washed class of ?uoro-substituted alkyl group derivatives of with a benzene-n-hexane (50:50) solution. This gave 3 picramide and tetryl. tri?uoromethyl picramide which decomposed at 195° C. A further object of this invention is the preparation of and changed from the red to the yellow isomorphic form. novel dyestuffs and dyed textile materials. 55 The new compounds of this invention have the fol EXAMPLE 3 lowing structural formula: The nitration of 3 - trifluoromethyl-2,4,6-trinitro-N methylaniline from Example 1 was accomplished :by dis solving 12.5 g. (0.04 mole) of the amine in 100 ml. of 60 concentrated sulfuric acid, cooling externally with an ice bath, then slowly adding 15 ml. of concentrated nitric acid with stirring. After the reaction solution had been allowed to stand for several hours at room temperature it was- poured over about 500 g. of shaved ice and the precipitated white solid was collected on a ?lter and air wherein R1 may be hydrogen or a nitro radical and R2, dried. Recrystallized from 95% ethanol yielded 12 g. R3 and R4 may each represent hydrogen, a monovalent (84.5% yield) of 3-tri?uoromethyl-2,4,6-trinitrophenyl lower alkyl radical having from 1 to 5 carbon atoms, or methylnitramine as a white solid. a ?uoro-substituted monovalent lower alkyl radical hav ing from 1 to 5 carbon atoms provided that at least one 70 EXAMPLE 4 of the substituents R2, R3 and R4 is a ?uoro-alkyl group. To a solution of 49.4 g. (0.2 mole) picryl fluoride in Illustrative of the lower alkyl and ?uoro-substituted 400 ml. of 95% ethanol was added 33.5 g. (0.25 mole) of 3,562,333 4 tri?uoroethylamine hydrochloride. This suspension was mine, the reaction product from Example 5, is between heated to dissolve the solids, then cooled externally with 340° C. and 360° C. and, hence, is more stable to heat an ice bath. At this point, 50 g. (0.5 mole) of solid sodium than those prior known explosives set forth in Table I. carbonate was added slowly with moderate stirring. Evi The explosion temperature of ethyl tetry-l is between 260° dence of the reaction was noted by a slight temperature 5 C. and 280° C. The explosion temperature of Table I is rise, evolution of CO2 and the presence of the character defined as that temperature in degrees centigrade required istic amine odor. The deep~orange solution was then heated to cause an explosion in 5 seconds. on the steam bath for about one hour, poured onto ice TABLE II and acidi?ed with 3 N hydrochloric acid to congo red. Impact sensitivity The light-yellow solid was collected on a ?lter, washed 10 with cold water and air-dried. Recrystallized from 95% Explosive: Impact height, cm. ethanol yielded 38.8 g. (62.5% yield) of N-beta,beta,beta Tetryl ______2742 tri?uoroethyl - 2,4,6 - trinitroaniline as a yellow solid; M.P.=67—70° C. Further recrystallization from 95% RDX ______25 PETN ______._ 12-1 3 ethanol yielded 28.7 g. of pale-yellow crystals; M.P.= 15 Nitro glycerin ______4-6 73.5—74.0° C. " Picric acid ______73-93 Analysis.—-Calculated for CBH5N4OSF3 (percent): C, TNT ______l 5 8-—l7 1 30.98; H, 1.62; N, 18.06; F, 18.4. The actual values found Ethyl tetryl 1 ______81 were (percent): C, 31.24; H, 1.74; N, 18.21; F, 18.3. 20 TP ethyl tetryl 2 ______f1 5 6 EXAMPLE 5 1 2,4,G-trinitrophenyletllylnitramine. The nitration of N-beta,beta,beta-tri?uoroethyl-2,4,6 2 2,4,S-trinitrophenyl-beta,beta,beta-tri?uoroethylnitramine. trinitroaniline of Example 4 was accomplished by dis From an examination of the information presented in solving 12.5 g. (0.035 mole) of the amine in 250 ml. of Table II, it can be seen that 2,4,6-trinitrophenyl-beta,beta, beta-tri?uoroethylnitramine, the reaction product from concentrated sulfuric acid, cooling externally with an ice N) Or bath, then slowly adding 14 ml. of concentrated (90%) Example 5, is less impact sensitive, with the exception of nitric acid with stirring, keeping the temperature below TNT, than the prior known explosives referred to in 10° C. during the addition. After the reaction solution Table II. The impact height of Table II is de?ned as that had been allowed to stand for several ‘hours at room tem height in centimeters for 50% ?re using an ERL machine with a type 12 tool (25 kilograms weight). perature, it was poured over about 1 kg. of shaved ice. 30 The precipitated white solid was collected on a ?lter and An explosive compound is considered to be stable if air-dried. lRecrystallized from 95% ethanol yielded 12.1 less than 2 cc. of gas, corrected to normal temperature and g. (98% yield) of 2,4,6-trinitrophenyl-beta,beta,beta-tri pressure, are evolved per gram per 48 hours at 100° C. ?uoroethylnitramine as a white solid; M.P. 116—118° C. Stability tests show that 2,4,6-trinitrophenyl-beta,beta,beta tri?uoroethylnitramine evolves less than 2 cc. of gas at Analysis.—Calculated for C8H4N4O8F3 (percent): ‘C, 35 27.05; H, 1.14; N, 19.72; F, 16.1. Molecular weight (Rast 100° C. for 48 hours and, hence, is placed in satisfactory Camphor), 301.18. The actual values found were (per stability Class I. All military explosives, such as am cent): C, 27.46; H, 1.29; N, 19.92; F, 16.3. Molecular monium picrate, PETN, RDX, tetryl and TNT, must meet weight, 295. this criterion. The power of 2,4,6-trinitrophenyl-beta,beta, Tetryl, when dissolved in sulfuric acid, is connected to 40 beta-tri?uoroethylnitramine is 125% that of TNT as methyl picramide (2,4,6-trinitro-monomethyl-aniline) and measured by the trauzl lead block test. nitric acid. This ‘fact is utilized to determine the presence From a consideration of the foregoing, it can be seen of the nitramine linkage (—N—NO2) in organic mate that the present invention provides a new class of explosive rials. The nitric acid produced in the reaction oxidizes compounds which are especially useful when employed as explosives in military munitions. These compounds exhibit diphenylamine (colorless) to a quinoidimonium sulfate of 45 N,N'-diphenylbenzidene (blue). It was found that both a high explosive potential together with a minimum sus tetryl and ethyl tetryl (2,4,6-trinitrophenylethylnitramine) ceptibility to shock and heat. react at once at room temperature; however, tri?uoroethyl The reaction products of Examples 1, 2 and 4 are repre tetryl gives a color reaction slowly at steam bath tem sentative of a new class of compounds; namely, ?uoro alkyl and N-?uoro-alkyl-substituted picramides. This class peratures. This decreased lability of the N-nitro linkage is 50 attributed to the inductive effect of the ?uorine substitu of compounds, in addition to being useful as explosives, tion on the ethyl group. dyes natural and synthetic ?bers yellow and their am The following two tables disclose the thermal and im monium salts dye those ?bers red. Representative of the pact sensitivity of prior known explosives and compares N-?uoro-alkyl and ?uoro-alkyl-substituted nitramines are them with the compounds of this invention. The informa 55 the reaction products of Examples 3 and 5. tion set forth in Table I may be found in the Encyclopedia Obviously many modi?cations and variations of this of Chemical Technology, edited by R. E. Kirk and D. F. invention may be made without departing from the spirit Othmer, vol. ‘6, pp. 54 and 1551, 'Interscience Encyclo and scope thereof and only such limitations should be pedia, Inc. New York, N.Y. The impact sensitivity data imposed as fall within the scope of the appended claims. of Table II was ascertained by the Naval Ordinance What is claimed is: Laboratory and may be found in Navord Report 5335, 60 1. The compounds having the formula: Impact Sensitivities, (Oct. 18, 1956), by W. P. Besser and P. G. Rivette. TABLE I R1—II\I-—Rz Thermal sensitivity 65 O2N—- N02 Explosive: Explosion temperature, ° C. R3 —R4 Tetryl ______257 lo. RDX ______260 70 PETN ______225 where R1 is selected from the group consisting of hydrogen Nitroglycerin ______222 and a nitro radical; and R2, R3 and R4 are each selected Picric acid ______322 from the group consisting of hydrogen, a monovalent It has been found that the explosion temperature of lower alkyl radical, and a ?uoro-substituted monovalent 2,4,6 - trinitrophenyl - beta,beta,beta - tri?uoroethylnitra 75 lower alkyl radical provided that at least one of the sub 3, 562,333 6 stituents R2, R3 and R4 is ?uoro-substituted monovalent References Cited lower alkyl radical UNITED STATES PATENTS 2 . 3 4'11n “Home 11 ‘y 1-2 ’ 4,6-t'“mm '1 -N- me 1111yamme '1' . 3,418,372 12/1968 Taylor ______149__105X 3. 3-tr_i?uorqrnve_thyl pi/cramide: _ _ miief’a-tn?uoromethyl - 2,4,6 - tnmtrophenylmethyl-mtra- 5 LELAND A. SEBASTIAN’ Primary Examiner 5. N-betazb§ta,beta-tri?uoroethyl-2,4,6ttrinitroanilirTe. Us CL X_R_ migé.2,4,6-tr1n1tr0phenyl~beta,beta,beta-tn?uoroethylnltra- 149__105; 26O_578