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Home , Isocyanic acid

3,040,082 United States Patent 0 i ICC Patented June 19, 19627 1 2 in or dissolved in inert such as hydrocarbons and 3,040,082 therein used for further reactions. The group ?-POLYHALO-a-HYDROXYISOCYANATES AND of the new compounds obtained by the process of this in THEIR PREPARATION , Fred W. Hoover, Wilmington, Del., assignor to E. I. du vention reacts with compositions containing an active Pont de Neznonrs and Company, Wilmington, Del., a 5 , e.g., alcohols and , to form hydroxyl corporation of Delaware . containing derivatives. They react with polymers, such as No Drawing. Fiied Dec. 24, 1958, Ser. No. 782,673 cotton or nylon, e.g., when fabric is dipped into a solu 12 Claims. ((31.260-453) " tion of the compound until the fabric contains about 1—2% of the compound, and subjected to baking at about 150° This invention relates to, and has as its principal ob 10 C. for 30 minutes, the fabric has increased repellen jects provision of, novel ,8-polyhalo-rx-hydroxy- cy. The compounds are herbicidal to grasses such as and a preparation of the same. Johnson grass. They can also be converted to high lsocyanates having a-hydroxyls have heretofore never molecular weight relatively inert polymers upon heat been obtained. I ones and Powers, J. Am. Chem. Soc. 46, mg. 2518 (1924) suggested that a-hydroxymethyl, a-hydroxy 15 The following examples further illustrate the prepara ethyl, and a-hydroxybenzyl isocyanates might be inter tion and use of the new compounds of this invention. mediates in Lossen-Curtius-Hoffman rearrangements. EXAMPLE I Their work showed, however, that these compounds were not capable of existence. ' ' Bis(Chlorodi?uoromethyl)Hydroxymethyl isocyanate Contrary to the teachings of the literature, there have 20 now been obtained a-hydroxyisocyanates. These new (ClF2C) 2CO+HNCO-—>(CIF2C)2C(OH)NCO compounds have at least two halogens on a til- and > To s-dichlorotetra?uoroacetone (4.5 g.) cooled to —78° result from the reaction of with an aldehyde C. was added 1.2 g. of isocyanic acid. The resultant mix or ketone (i.e., OX0 or ketaldone compound) having at ture was allowed to warm up slowly to room temperature. least two halogens on an a-carbon. Particularly preferred 25 On distillation, 2.4 g. of bis(chlorodi?uoromethyl)hy compounds of this invention have the formula droxymethyl isocyanate, B.P. 26—27° C./7 mm., was ob tained. The structure of this novel compound was con ?rmed by its infrared, near infrared and proton spectra, content and chemical behavior. . 1121 1'22 30 Arzalysis.—Calcd. for C4HO2NF4Cl2: N, 5.79. Found: wherein X and Y are halogens; especially chlorine and/or N, 6.03. ?uorine; R1 is hydrogen, halogen, hydrocarbon or halo Bis(chlorodi?uoromethyl)hydroxymethyl isocyanate hydrocarbon; R2 is hydrogen, hydrocarbon or halohydro has utility as a plant growth modi?er for many plants carbon; or R1 and R2 together are divalent hydrocarbon such as beans. For example, when applied as a 1% solu or halohydrocarbon radicals of 2-4 . These par— 35 tion in to the leaves of these plants, internode ticularly preferred compounds have between 3 and 11 shortening occurs. ' carbons, inclusive, and contain halogen of atomic num Bis(chlorodi?uorome?1yl)hydroxymethyl isocyanate ber 9-35, i.e., ?uorine, chlorine and bromine. was converted to the corresponding ureido derivatives by The process whereby the new oc-hYdl‘OXY-B-POlYhSlO reaction with aniline. Aniline (3.72 g.) was added drop isocyanates are obtained involves the reaction of isocyanic 40 wise at —5 ° C. to a stirred mixture of 9.7 g. of bis(chloro acid with a carbonyl compound (i.e., aldehyde or ketone) di?uoromethyl)hydroxymethyl isocyanate and 25 ml. of having at least two halogens on a-carbons at a temperature . After standing overnight, removal of the below the decomposition temperature of the new com under reduced pressure left (95%) of 1-(bis(chlorodi pounds. The temperature varies for the speci?c com ?uorornethyl)hydroxymethyl) - 3 - phenyl . It melted pounds obtained but generally is below about 10° C. and 45 at 75—77° C. after recrystallization from carbon tetra preferably not above 0° C. The new gz-hydroxyisocyan chloride. ' ates are generally stored at low temperatures before their Analysis.—Calcd. for C10H3O2N2F4Cl2I N, F, use. 22.68. Found: N, 8.82; F, 22.09. , The reaction involves the addition of isocyanic acid to 1 - (bis(chlorodi?uoromethyl)hydroxymethyl) - 3 - the carbonyl compound in equimolar ratios. Carbonyl phenylurea is a herbicide, being particularly e?ective on compounds that can be used in the above reaction are grasses such as Johnson grass when applied in an acetone those of 2 to preferably not more than 10 carbons. The solution at the rate of 16 lbs/acre. compounds generally used have the formula

1'1. 1%. A mixture of 11.2 g. of tri?uoroacetaldehyde and 5 g. wherein the values of X, Y, R1, and R2 are those given of isocyanic acid was prepared at -78° C. and warmed previously. The following oxo compounds are useful in 60 slowly to 0° C. The infrared spectrum and the near in the process of this invention to form new az-hydroxyiso frared spectrum of this mixture clearly indicated that L2 : a,a~dichlorocyclohexanone, oz,oc-dl?l10IOCYClO Z-tri?uoro-l-hydroxyethyl isocyanate had been obtained. hexanone, per?uoroheptan-li-one, 1,1,1-tribromoacetone, This hydroxyisocyanate underwent va rapid exothermic tribromoacetaldehyde, dichloro?uoroacetaldehyde, a,a-di reaction at room temperature to form a viscous polymeric chlorocyclopentanone, and octa?uorocyclopentanone. material. However, 2,2,2-tri?u’oro-l-hydroxyethyl iso The new compounds of this invention are highly re could be distilled from one trap to another at active. In general they do not undergo polymerization about 0° C. ‘ ‘ reactions at 0° C. or below. Some of the compounds, par Further evidence for the hydroxyisocyanate structure ticularly the ?uorine-containing compounds, are stable at was shown by the formation of the corresponding ureido room temperature and can be distilled at reduced pressure compounds. For example, tola mixture of 10.5 g. of l at low temperatures. However, for most uses the new hydroxy-2,2,2-tri?uoroethyl isocyanate, 10 ml. of ether compounds need no puri?cation. They can be prepared and 5 m1. of maintained at —15° 3,040,082 3 4 C. was added, 5.4 g. of aniline over a period of 30 boiling at 10.5-12.5 ° C., is collected. This product strong minutes. The resultant mixture was allowed to stand ly —reduces potassium permanganate solution and bromine. overnight at room temperature ‘and the solvent then re Step II.—-Preparati0n 0]‘ per?uorocyclobutyl methyl moved under reduced pressure. There was obtained 10.6 ether. A thick-walled cylindrical glass reactor is cooled g. (68%) of l-(1—hydroxy-Z,2,2~tri?uoroethyl)—3-phenyl in —a liquid nitrogen bath and charged with 11.5 parts of ' urea. Both the infrared spectrum ‘and the elemental methyl tri?uorovinyl ether, 0.5 part of phenothiazine in analyses were in good agreement with this structure. hibitor, about 0.5 part of a commercially avail-able terpene Analysis.—-Calcd. for C9'H9O2N2C13: N, 9.88; Cl, 37.50. stabilizer (see U.S. Patent 2,407,405) and 23 parts of Found: N, 9.97; CI, 37.52. tetra?uoroethylene. The reactor is then sealed and 10 heated to 150° C. and held at this temperature for 12 EXAMPLE III N hours. The sealed reactor is ‘allowed to cool to room 1H,5H~Octa?uor0-1—Hydroxypentyl Isocyanate temperature, cooled to liquid nitrogen temperature, and ?nally opened to the atmosphere. The reactor is warmed HC4F8CHO + HNCO—>HC4FBCH ( OH) NCO carefully to vent any unreaoted tetraflnoroethylene or any A mixture of 15.5 g. of SH-per?uorovaleraldehyde and— 15 dimer thereof formed during the reaction. By work-up 2.9 g. of isocyanic acid, prepared at —78° C., was kept of the remaining liquid, there is obtained per?uorocyclo at 0° C. for 16 hours and then allowed to warm to room butyl methyl ether, a clear colorless liquid boiling at 56° temperature. The near infrared spectrum of the product C. at atmospheric pressure, nD25=1.2875. indicated that substantially all of the isocyanic acid had Step IlI.—Prep‘aration of per?uorocyclobuz‘anone hy been converted to the hydroxyisocyanate and that virtual 20 draze. A heavy-walled glass reactor is charged with eight ly all of the carbonyl groups had undergone reaction. . parts of per?uorocyclobutyl methyl ether and 18.8 parts The corresponding ureido derivative was formed as of concentrated . The reactor and contents follows: A solution of aniline (5 g.) in ether (25 ml.) are cooled and the reactor sealed and heated at 150° C. was added at —-15° C. to a mixture of lH,5H-octa?uoro for twelve hours. There is thus obtained 5.9 parts of l-hydroxypentyl isocyanate (13.7 g.) ‘and 60 m1. of ether. 25 per?uorocyclobutanone hydrate. The resultant mixture was allowed to stand for 72 hours. Step IV.—Preparati0n‘0f per?uorocyclobufanone. A On evaporation of the solvent there remained 18 g. glass reactor ?tted with a dropping funnel and connected to a trap cooled~with a solid carbon-dioxide/actone bath (98%) of 1-(lH,5H-octa?uoro - 1 - hydroxypentyl)-3 phenylurea. Both the elemental analysis and the infra is charged with 25 parts of phosphorus pentoxide. The red spectrum were in, good agreement with the ureido 30 reactor and attached system are then evacuated ‘and ?lled structure. with nitrogen at 200 mm. of mercury pressure. Molten Analysis.—Calcd. for C12H10O2N2F8: N, 7.65; F, 41.51. per?uorocyclobutanone hydrate, 16.5 parts, is added Found: N, 7.62; F, 41.22. through the dropping funnel. On warming the reactor an exothermic reaction occurs and per?uorocyclobutanone 35 collected as a solid in the trap. The ketone boils at about 0-1° C. EXAMPLE V 1-Hydroxy-2,2,2-Trichloroethyl Isocyanate 40 CCI3CHO —l-HNCO-e CClgCH (OH) NCO A mixture of 4.14 g. of isocyanic acid and 14.2 g. of 'Isocyam'c acid (2.5 g.) was distilled into a vessel con taining 10 g. of per?uorocyclobutanone at —78° C. and chloral was prepared at —78° C. and then warmed to 0° C. and held at this temperature for several hours. The the resultant mixture warmed slowly to room tempera near infrared spectrum of samples taken periodically over ture. The near infrared spectrum of this product clearly a period of 24 hours showed that l-hydroxy-2,2,2-tri showed that 1—hydroxyhexa?norocyclobutyl isocy-anate chloroethyl isocyanate gradually formed and that after 24 had been formed. An attempt to distill l-hydroxyhexa ?uorocyclobutyl isocyanate at 40° C. under reduced pres hours the reaction was substantially complete. Both the infrared spectrum and chemical evidence were in accord sure gave ‘a viscous liquid, presumably a low molecular Weight polymer. with the hydroxyisocyanate structure. 1-hydroXy-2,2,2 1—hydroxyhexa?uorocyclobutyl isocyanate is useful to trichloroethyl isocyanate is a low-melting solid (M.P., impart water and oil repellancy to fabrics such ‘as cotton, 25° C.) which undergoes an exothermic reaction at room nylon, and “Dacron” (Du Pont trademark for polyester temperature, presumably to form low molecular weight ?ber). 55 polymeric materials. With aniline, it forms the corre Per?uorocyclobutanone, a novel compound claimed sponding ureido compound (M.P., 145° C.). elsewhere, may be prepared as follows: Analysis.-—Calcd. for C9H9O2N2Cl3: N, 9.88; Cl, 37.51. Step I.—Prepamti0n of methyl tri?uorovz'nyl ether. Found: N, 997; C1, 37.52. This derivative was found to A mixture of 33.3 g. (0.62 mole) of dry sodium meth have utility as a herbicide; for example, when applied oxide and 155 g. of sodium-dried dioxane is placed in a 60 in acetone solution at rates as low as 2 lbs./ acre, it was 320-ml. stainless steel bomb. The bomb is sealed, pres a pre-emergence herbicide, particularly for plants such as sured to 300 p.s.i. with tetra?uoroethylene, and heated millet. to 100° C. under agitation. The bomb is repressured EXAMPLE VI with tetra?uoroethylene ‘as is, necessary to maintain 300 p.s.i. of pressure. The reaction is continued until no fur 65 2,2-Dichl0r0-1—Hydroxyethyl Isocyanate ther decrease in pressure occurs. The bomb is cooled and the exit gas is led into traps immersed in a Dry-‘ice OH acetone bath. The greater portion of the recovered ma OhCHCHO + HNCO ——> ClzCHOH terial boils'below —20° ‘C. but the trap residue is com N00 bined with the contents of the bomb Iand the combined 70 material is distilled through a 12-inch Vigreux column. A mixture of 2.2 kg. of isocyanic acid and 6.6 g. of di Material weighing 30.7 g. and boiling in the range 21 chloroacetaldehyde was prepared at —78° C. and warmed 45° C. is collected. This material is redistilled through to 0° C. A clear, homogeneous product was obtained. a! 3-foot low temperature column packed with glass The near infrared spectrum of this product showed that helices. Nineteen grams of methyl tri?uorovinyl ether, 75 2,2-dichlo1'o4l-hydroxyethyl isocyanate had been formed. 6 EXAMPLE VII carbons to which it is attached selected from the group Bis(hepta?uoropropyl) -1 -Hydroxymethyl Isocyanate consisting of hydrogen, halogen and monovalent an di valent saturated aliphatic hydrocarbon and halohydrocar OH bon, no halogen being attached to the carbon alpha to the c=F1C0OaF1 + HNCo —> ctmocgm isocyanate group and all halogen in said compound being two selected from the group consisting of ?uorine, chlorine and bromine. A mixture of 12.8 g. of per?uorodipropylketone and . Bis(chlorodi?uoromethyhhydroxymethyl isocyanate. 1.4 g. of isocyanic acid was prepared at -80° C. and . 2,2,2-tri?uoro-l-hydroxyethyl isocyanate. warmed to 0° C. The near infrared spectrum of the 10 . 1H,5H-octa?uoro-l-hydroxypentyl isocyanate. resultant liquid showed that bis(hepta?uoropropyl)-l-hy-. . 1-hydroxyhexa;?uorocyclobutyl isocyanate. droxymethyl isocyanate had formed. . 1-hyd.roxy-2,2,2-trich1oroethylisocyanate. _ EXAMPLE VIH 7. The process of preparing a halogenated saturated Cyclic Derivatives of Hydroxyisocyanates aliphatic a-hydroxyisocyanate which comprises reacting 15 isocyanic acid with a member of the group consisting of Oxadiazinediones result from the reaction of hydroxy~ halogenated saturated aliphatic aldehydes and ketones of isocyanates with themselves: 2-10 carbons in which all substituents are selected from A. When I10.5 g. of 2,2,2-trichloro-1-hydroxyethyl iso the group consisting of ?uorine, chlorine and bromine and cyanate (Example V) in 9 m1. of of having at least two of such substituents on a carbon alpha glycol was stirred with 1 g. of water for an 20 to the carbonyl group at a temperature below about room hour at 0° C., there was obtained a 30% yield of 6 temperature. ' ,trichloromethyl-l,3,5-oxadiazine-2,4-dione’ melting (with 8. The process of preparing bis(chlorodi?uorornethyl) dec.) at 190-200” C. hydroxymethyl isocyanate which comprises reacting iso Analysis.—-Calcd. for C‘H3O3N2Cl3: C, 20.55; H, 1.30‘; cyanic acid with s-dichlorotetra?uoroactone at a temper N, 12.00; Cl, 45.60. Found: C, 20.68; H, 1.76; N, 12.03; 25 ature below about room temperature. Cl, 45.50. 9. The process of preparing 2,2,2-tri?uoro-l-hydroxy B. To 1.63 g. of bis(chlorodi?uoromethyl)hydroxy ethy'l isocyanate which comprises reacting isocyanic acid (Example I) was added a drop of pyri with tri?uoroacetaldehyde at a temperature below about dine at room temperature. An exothermic reaction took 0° C.‘ ~ place with the formation of a white solid which was re 30 10. The process of preparing lH,5H-octa?uoro-1-hy crystallized from . The 6,6-bis(chlorodi?uoro droxypentyl isocyanate which comprises reacting isocyanic methyl)-l,3,5-oXadiazine-2,4-dione melted at 98—99‘' C. acid with SH-per?uorovaleraldehyde at a temperature be Analysis.—Calcd. for C5H2Cl2F4N2O3: C, 21.06; H, low about room temperature. ' 0.71; N, 9.83; F, 26.65; M.W., 285. Found: C, 21.36; 11. The process of preparing l-hydroxyhexa?uoro H, 0.99; N, 9.84; F, 26.35; M.W., 279. ‘ 35 tcyclobutyl isocyanate which comprises reacting isocyanic These oxadiazinediones have herbicidal activity; e.g., acid with per?uorocyclobutanone at a temperature below when applied in an acetone solution at a rate of ,2-16 about room temperature. lb./ acre, growth of broad leaf plants and grasses such as 12. The process of preparing l-hydroxy-2,2,2—trichloro Johnson grass was controlled. ethyl isocyanate which'comprises reacting isocyanic acid Since obvious modi?cations in the invention will be 40 with chloral at a temperature below about 0° C. evident to those skilled in the chemical arts, I propose to be bound solely by the appended claims. References Cited in the ?le of this patent The embodiments of the invention in which an ex UNITED STATES PATENTS clusive property or privilege is claimed are de?ned as Reid ______Apr. 19, 1955 follows: 45 2,706,733 1. A compound of 3~11 carbon atoms having 2,883,388 England ______Apr. 21, 1959 formula OTHER REFERENCES Jones et al.: Iour. Amer. Chem. Soc., vol. 46 (1924), p. 2519. Bergmann: “The Chemistry of and Related Compounds,” 1948, p. 80. wherein X and Y are halogen and Z is at least one radical Rodd: “Chemistry of ,” volume '1, taken in sufficient number to satisfy the valences of the part A, pp. 478-479.