one embodiment of the present invention provides chemical precursors from which organic peroxy acids may be prepared upon their being mixed with hydrogen peroxide or another suitable peroxide precursor , such as percarbonate or perborate anions or species , in aqueous media . the inventive compounds include those described by the chemical formula : in which l is a divalent radical that is independently selected from the group consisting of : and wherein r 1 is independently any c 1 to c 20 hydrocarbyl group ; r 2 is independently selected from the group consisting of : hydrogen , any c 1 to c 20 hydrocarbyl group , and the group : in which r 5 is independently hydrogen or any c 1 to c 20 hydrocarbyl group ; r 3 is independently selected from the group consisting of : hydrogen and any c 1 to c 20 hydrocarbyl group ; and r 4 is independently selected from the group consisting of : hydrogen , and the group in which r 5 is independently hydrogen or any c 1 to c 20 hydrocarbyl group . the precursors of this embodiment of the invention are conveniently prepared by reacting an acid halide of a carboxylic acid with various substituted or unsubstituted sulfamides and sulfoxamides in an appropriate solvent . an acid halide of a carboxylic acid is often referred to by those skilled in the art as simply an “ acid halide ”. acid halides of carboxylic acids , ( including without limitation alkyl carboxylic acids , aryl carboxylic acids and alkylaryl carboxylic acids ), are well known in the art , and are believed to be described in all reputable college - level organic chemistry textbooks , one example being “ introduction to organic chemistry ”, by streitweiser and heathcock , 2 nd ed . macmillan publishing company , new york ( 1981 ), the entire contents of which are herein incorporated by reference , especially pages 517 , et seq . the acid halides of carboxylic acids may be formed as the reaction product between a carboxylic acid and a suitable halogenating agent such as the trichloride and pentabromide of phosphorous , or the thionyl halides such as thionyl chloride and thionyl bromide , under conditions well known to the organic chemist . in the formation of acid halides by this route , the hydroxy group of the carboxylic acid function is replaced by a halogen atom , usually chlorine or bromine . thus , in general , an acid halide useful for forming a precursor in accordance with the present invention has the chemical structure : in which r is any c 1 to about c 20 hydrocarbyl group , and in which x is any halogen atom . this definition includes the acid halides of alkyl carboxylic acids , as well as the acid halides of aryl carboxylic acids and alkylaryl carboxylic acids . according to one preferred form of the invention , the halogen atom x comprises bromine or chlorine . the term “ hydrocarbyl ”, when referring to a substituent or group in the present specification and the claims appended hereto is used in its ordinary sense , which is well - known to those skilled in the art . specifically , it means a group having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character . examples of hydrocarbyl substituents or groups include : ( 1 ) hydrocarbon substituents , that is , aliphatic ( e . g ., alkyl or alkenyl ), alicyclic ( e . g ., cycloalkyl , cycloalkenyl ) substituents , and aromatic -, aliphatic -, and alicyclic - substituted aromatic substituents , as well as cyclic substituents wherein the ring is completed through another portion of the molecule ( e . g ., two substituents together form an alicyclic radical ); ( 2 ) substituted hydrocarbon substituents , that is , substituents containing non - hydrocarbon groups which , in the context of this invention , do not alter the predominantly hydrocarbon substituent ( e . g ., halo ( especially chloro and fluoro ), hydroxy , alkoxy , mercapto , alkylmercapto , nitro , nitroso , and sulfoxy ); ( 3 ) hetero substituents , that is , substituents which , while having a predominantly hydrocarbon character , in the context of this invention , contain other than carbon in a ring or chain otherwise composed of carbon atoms . heteroatoms include sulfur , oxygen , nitrogen , and encompass substituents as pyridyl , furyl , thienyl and imidazolyl . in general , no more than two , preferably no more than one , non - hydrocarbon substituent will be present for every ten carbon atoms in the hydrocarbyl group ; typically , there will be no non - hydrocarbon substituents in the hydrocarbyl group . all hydrocarbyl groups are useful within the meaning of r in the above formula for the acid halide , subject to the proviso that no portion of the hydrocarbyl radical r present is detrimentally reactive with the labile carbonyl - halogen bond also present within the time frame of the use of such acid halide in preparation of the targeted precursor . thus , typical acid halides suitable for use in preparing a precursor according to the present invention include , without limitation : acetyl chloride , adipoyl chloride , anisoyl chloride , acryloyl chloride , butyryl chloride , camphoroyl chloride , caproyl chloride , cinnamoyl chloride , cyanoacetyl chloride , formyl chloride , proprionyl chloride , fumaroyl chloride , glutaryl chloride , isophthaloyl chloride , levulinoyl chloride , lauroyl chloride , malonyl chloride , oleoyl chloride , oxalyl chloride , pyruvoyl chloride , salicyloyl chloride , stearoyl chloride , suberoyl chloride , terephthaloyl chloride , thioacetyl chloride , phthaloyl chloride , succinyl chloride , benzoyl chloride , maleyl chloride and toluoyl chloride . in fact , all known acid halides are in principle useful as acid halides from which a precursor according to the invention may be provided , owing to the presence of an active hydrogen atom in the molecular structure of the co - reactant with which the acid halide is reacted to form the inventive precursors . the co - reactant used as a precursor with which an acid halide is reacted in order to form a precursor of the invention is selected from the group consisting of substituted or unsubstituted sulfamides and sulfoxamides . sulfamide is a compound well - known to have the structure : and sulfoxamide is a compound well known in the art to have the structure : each of these compounds comprise two nitrogen atoms , each of which have at least one active hydrogen atom attached thereto . for purposes of this invention and the appended claims , a hydrogen atom attached to a nitrogen atom of a substituted or unsubstituted sulfamide or sulfoxamide is considered to be an active hydrogen atom if it is capable of participating in the zerevitinov reaction ( th . zerevitinov , ber . 40 , 2023 ( 1907 )) to liberate methane from methylmagnesium iodide . further , each of these compounds sulfamide and sulfoxamide continue to contain an active hydrogen atom when one or more of their nitrogen atoms are mono - substituted with a hydrocarbyl group , thus rendering them reactive with an acid halide and suitable for use in providing a precursor according to the invention . for convenience , the substituted and unsubstituted sulfamides and sulfoxamides used as an initial raw material in providing a composition or compound according to the invention may be collectively denoted as : in which l is a divalent radical that is selected from the group consisting of : and wherein r 2 and r 3 are each independently selected from the group consisting of : hydrogen and any c 1 to c 20 hydrocarbyl group . thus , the preparation of a precursor according to one preferred embodiment of the invention may be accomplished by conducting the reaction : in this reaction , one mole of acid halide is shown to be reacted with each mole of substituted or unsubstituted sulfamide ( or sulfoxamide when selected ) reactant , and although not specifically written , in the process a mole of hydrogen halide hx is liberated . however , those of ordinary skill in the art readily appreciate that more than one mole of acid halide may be employed per mole of sulfamide ( or sulfoxamide when selected ). particularly , when r 2 and r 3 are both hydrogen , it is possible to append up to four groups having structure : in which r 5 is independently hydrogen or any c 1 to c 20 hydrocarbyl group to the starting material : thus , one embodiment of the invention provides a precursor which may be formed according to the reaction : in which 2 moles of the same acid halide are reacted with each mole of sulfamide ( or sulfoxamide , when selected ), and in such a process two moles of hydrogen halide hx are liberated . in the above two reactions , the identities of the various substituents are as previously described , namely l is a divalent radical that may be either of and r 1 may be any c 1 to c 20 hydrocarbyl group ; and r 2 and r 3 are each independently selected from the group consisting of : hydrogen and any c 1 to c 20 hydrocarbyl group . in which l is a divalent radical that may be either of n preferably has the value of either one or two ; r 1 may independently be any c 1 to c 20 hydrocarbyl group ; r 2 , and r 3 in the reactant may independently be hydrogen , or any c 1 to c 20 hydrocarbyl group , and r 2 and r 3 in the product are each independently hydrogen , any c 1 to c 20 hydrocarbyl group , or the group : in which r 5 is independently hydrogen or any c 1 to c 20 hydrocarbyl group , and r 4 is hydrogen or the group : in which r 5 is independently hydrogen or any c 1 to c 20 hydrocarbyl group . alternate preferred embodiments include the cases where n is selected to be 3 when at least one of r 2 and r 3 in the reactant are hydrogen , and where n is selected to be 4 when both of r 2 and r 3 in the reactant are hydrogen . the liberated hx is not specified in the general reaction but is recognized as being liberated by those skilled in the art , in a quantity that depends upon the total amount of acid halide and active hydrogen atoms present in the reactant sulfamide or sulfoxamide . thus , using a process as described above in combination with the specified starting materials , the invention provides compositions of matter useful for forming peroxygen acids , which comprise an amino compound having the structure : in which l is a divalent radical that is independently selected from the group consisting of : and wherein r 1 , r 2 , r 3 , and r 4 are each independently selected from the group consisting of : hydrogen , any c 1 to c 20 hydrocarbyl group , and the group : in which r 5 is in each occurrence independently hydrogen or any c 1 to c 20 hydrocarbyl group . in a preferred embodiment , at least one of r 1 , r 2 r 3 , and r 4 are the group : in which r 5 is in each occurrence independently hydrogen or any c 1 to c 20 hydrocarbyl group . in another preferred embodiment , at least one of r 1 and r 2 are the group : in which r 5 is in each occurrence independently hydrogen or any c 1 to c 20 hydrocarbyl group and at least one of r 3 and r 4 are the group : in which r 5 is in each occurrence independently hydrogen or any c 1 to c 20 hydrocarbyl group . the processes in all of the these reactions set forth above are considered to be acylation reactions , and their reaction products are useful in preparing solutions containing peroxygen acids upon their being mixed with an aqueous peroxide such as hydrogen peroxide or a peroxide precursor , such as percarbonate or perborate anions , in aqueous media . the acylation reactions described above for preparing the precursors of the invention are preferably carried out in a solvent , which solvent is preferably an organic solvent in which the acid halide and sulfamide ( or sulfoxamide , when employed ) are mutually soluble . in addition , it is preferable to add a small amount of tertiary amine , such as a tri - alkyl amine such as triethylamine , trimethylamine , pyridine , etc . to the solution to facilitate the reaction between the acid halide and sulfamide ( or sulfoxamide ), as the use of tertiary amines for this purpose is known in the art . it will be immediately recognized by those skilled in the art upon reading this specification that the identity of the hydrocarbyl groups r 1 and r 5 will often be the same , as in those cases when two moles of acid halide are combined with one mole of the sulfamide ( or sulfoxamide when selected ). however , it is possible for the identities of the hydrocarbyl groups r 1 and r 5 to be different from one another in a precursor product according to the invention , and such result is readily accomplished by first reacting a selected sulfamide ( or sulfoxamide ) having two active hydrogen atoms , either on the same nitrogen atom or on different nitrogen atoms , with a first acid halide , and then subsequently reacting the acylated product with a second acid halide having an r group that differs from that of the first acid halide . during the course of such reactions , owing to thermodynamic and kinetic equilibria , it is statistically probable that a portion of the reaction product will be one in which r 2 may comprise the group : in which r 5 may comprise the same group as r 1 , for the case when two moles of acid halide are reacted in a single reaction step with each sulfamide ( or sulfoxamide ) present , when the sulfamide ( or sulfoxamide ) initially comprises two active hydrogen atoms attached to the same nitrogen in the reactant ( with r 3 and r 4 being as specified above ) by the same token , in an alternate form of the invention r 5 in a radical : in the position of r 2 may comprise a different group than r 1 , for the case when two moles of acid halide are reacted in two separate reaction steps with each sulfamide ( or sulfoxamide ) present , when the sulfamide ( or sulfoxamide ) initially comprises two active hydrogen atoms attached to the same nitrogen in the reactant . thus , although the most kinetically favored reaction product is represented by : there will nevertheless also be present certain quantities of material represented by the structure : the relative amount of which depends on the nature of the r 1 group , as is readily appreciated by those skilled in the art , when the r 2 group in the reactant which results from the monoacylation of the sulfamide ( or sulfoxamide ) raw material : comprises hydrogen . thus , the present invention also includes compositions having the general structure : in which r 5 is independently hydrogen or any c 1 to c 20 hydrocarbyl group . however , the preferred inventive compounds are those described by the formula : in which l is a divalent radical that is independently selected from the group consisting of : and wherein r 1 is independently any c 1 to c 20 hydrocarbyl group ; r 2 and r 3 are each independently selected from the group consisting of : hydrogen and any c 1 to c 20 hydrocarbyl group ; and r 4 is independently selected from the group consisting of : hydrogen , and the group in which r 5 is independently hydrogen or any c 1 to c 20 hydrocarbyl group are water soluble at room temperature , are more efficient in generating peracids than currently - available commercial precursors , and these materials can be advantageously used as solid precursors to peroxy acids when mixed with hydrogen peroxide or a hydrogen peroxide precursor such as percarbonate or perborate . the following preparatory methods are intended to be exemplary of the present invention and shall not be construed to be delimitive thereof in any respect . synthesis of diproprionyl sulfamide — to 100 ml of toluene in a flask equipped with a reflux condenser and a mechanical stirrer under moderate agitation are added 9 . 6 grams of sulfamide and 10 . 1 grams of triethylamine , and stirring is continued until complete dissolution occurs . next , 9 . 25 grams of proprionyl chloride is added dropwise with stirring over the course of about 15 minutes , while the temperature of the flask is maintained below 60 ° c . after the addition of the proprionyl chloride is complete , the mixture is allowed to cool to room temperature , after which time it is filtered to remove the triethylamine hydrochloride by - product , which is discarded . the toluene is removed using a rotary evaporator until crystals just begin to form , at which time the flask contents are cooled to between about 2 - 8 ° c . overnight to complete crystallization process . the product is filtered , dried under vacuum , and stored in a dessicator . the overall reaction is : the procedure according to example 1 is followed , except 13 . 0 grams of propionic anhydride is utilized in place of the proprionyl chloride . synthesis of dipropionyl sulfoxamide — to 100 ml of toluene in a round bottom flask equipped with a reflux condenser and a mechanical stirrer under moderate agitation are added 8 . 0 grams of sulfoxamide and 10 . 1 grams of triethylamine until dissolution is complete . subsequently , 9 . 25 grams of proprionyl chloride is added dropwise with stirring by means of an addition funnel while taking care to maintain the mixture below 60 ° c . following the addition the mixture is allowed to cool to room temperature , and is filtered to remove triethylamine hydrochloride by - product , which is discarded . the toluene is evaporated using a rotary evaporator until crystals just begin to form , after which time the contents of the flask are cooled to between 2 - 8 ° c . and allowed to stand overnight to complete crystallization process . the product is filtered , dried under a vacuum , and stored in a dessicator the overall reaction is : the procedure according to example 3 is followed , except that 13 . 0 grams of propionic anhydride is utilized in place of the proprionyl chloride . an equimolar amount of sodium perborate and diproprionyl sulfamide are mixed with water sufficient to generate ˜ 0 . 4 % perpropionic acid . to make one liter of product mix 4 . 8 grams of diproprionyl sulfamide with 4 . 65 grams of sodium perborate and add one liter of water . the reaction mixture will be initially basic , then as the reaction proceeds the ph will drop . sufficient buffer such as sodium dihydrogen phosphate should be added such that the final ph is between ˜ 6 . 5 and ˜ 7 . 0 . to enhance microbial activity , ionic or nonionic surfactants such as dodecylbenzenesulfonic acid or pluronics may be added . sequestering agents such as ethylenediaminetetraacetic ( fdta ) acid may be added to improve microbial activity . for the sake of stability of an aqueous solution containing an amino compound according to the invention , it is preferred that the aqueous solution contain a ph buffer . the buffer chosen is not critical as long as the proper ph is maintained preferably in the range of between about 5 . 0 to 7 . 0 . a vast number of buffers are known to those skilled in the art , and any buffer known to those skilled in the art as being useful for maintaining an aqueous solution that contains an amino compound according to the invention in the range specified above may be used for this purpose , with the main proviso for suitability being that the components of such buffer are preferably stable with respect to the other chemical species in the aqueous solution . suitable buffer systems thus include without limitation : phosphate buffers ; sulfate buffers ; acetic / acetate buffers ; propionic / proprionate buffers ; c 1 - c 10 mono - and polycarboxylic acid buffers ; substituted carboxylic acids such as lactic , ascorbic , and tartaric acid buffers ; and carboxylic acids that have unsaturation such as maleic and furmaric buffers . buffer systems are known to contain salt pairs . currently , the most preferred buffer is the dihydrogen phosphate buffer , adjusted to a ph of about 6 . 5 . sequesterants may be used to advantage as a component of an aqueous solution that contains an amino compound according to the invention , for tying up or otherwise rendering chemically unavailable various species which may otherwise tend to interfere with the performance of the compounds and / or solutions of the invention . suitable sequesterants include those commonly employed in the surfactant and other industries , including without limitation edta or analogous phosphonic acid salts , tartarates , citrates , and other species recognized by those skilled in the art as capable of functioning as a sequesterant . other soluble conventional materials may be present to advantage as a component of an aqueous solution that contains an amino compound according to the invention , including corrosion inhibitors , dyes , perfumes , germicides , preservatives , e . g ., quaternium 15 , anti - tarnishing agents , surfactants ( for example anionic , cationic , nonionic , amphoteric or mixtures thereof ), thickeners , chelating agents , antioxidants , and the like . such other conventional materials may be used in the amounts they are normally used generally up to about 5 % by weight , more preferably up to about 3 % by weight . the invention also provides a process for disinfecting various microbes , including bacteria , molds , fungi and their spores which comprises contacting the vapor of peroxy acid generated as described herein in conjunction with a conventional means of vaporization selected from the group consisting of : heat , venturi nebulization , and sonication with at least one of said microbes . consideration must be given to the fact that although this invention has been described and disclosed in relation to certain preferred embodiments , obvious equivalent modifications and alterations thereof will become apparent to one of ordinary skill in this art upon reading and understanding this specification and the claims appended hereto . the present invention further includes all possible combinations of the features recited in the specification and / or any one of the various claims appended hereto with the features recited elsewhere in the specification and / or in any one or more of each of the remaining claims . for example , the present specification includes disclosure of a process according to claim 18 which comprises contacting a composition according to any of claims 1 - 17 with an aqueous peroxide . accordingly , the presently disclosed invention is intended to cover all such modifications , alterations , and combinations .
this present invention provides materials for use as solid or concentrated chemical precursors for the production of organic peroxy acids . organic peroxy acids are formed using a precursor according to the invention when they are combined with hydrogen peroxide or a hydrogen peroxide precursor such as a percarbonate or a perborate in aqueous medium . organic peroxy acids , such as peroxyacetic acid , are used currently to disinfect medical equipment such as endoscopes and related items .