Patent Publication Number: US-3880864-A

Title: Certain formylalkyl quaternary salts

Description:
United States Patent 91 Lincoln et al.  
 [ Apr. 29, 1975 [75] Inventors: Lewis L. Lincoln; Donald W.  
 Heseltine, both of Rochester, NY.  
 [73] Assignee: Eastman Kodak Company,  
 Rochester, NY.  
  221 Filed: on. 20, 1972 1211 Appl. No.: 300,559  
 Related US. Application Data [62] Division of Ser. No. 819,946, April 28, I969, Pat.  
 No. 3,759.9Ul.  
 [52] US. Cl 260/286 Q; 260/298; 260/302 R; 260/302 F; 260/302 H; 260/304; 260/307 R; 260/307 D; 260/309; 260/309.2; 260/326.l2;  
  260/326.l6 [5 l] Int. Cl C07d 91/44 [58] Field of Search 260/326.16, 309, 307 R,  
 260/302 R, 298, 286 Q, 309.2, 304, 302 F, 307 D, 326.]2, 302 H [56] References Cited UNlTED STATES PATENTS 2,068,824 l/l937 Schonhofer et al 260/286 Q 3,759,901 9/1973 Lincoln et al 260/240 G Primary Examiner-Richard J. Gallagher Attorney, Agent, or Firm-M. R. Chipaloski [57] ABSTRACT Reactive N-substituted, cyclammonium quaternary salts wherein the N-substituent includes substituted alkyl radicals whose terminal carbon atom can be additionally substituted with, for example, a formyl radical, an acetal or thioacetal grouping including cyclic oxyacetals and cyclic thioacetals, or a hydrazono radical which is itself optionally substituted, are useful as chemical intermediates, as photographic addenda such as antifoggants or as nucleating agents in silver halide reversal emulsions. The salts are prepared by reacting a hydro salt of a cyclammonium base with an aliphatic organic compound having an active double bond system between the first and second carbon atoms.  
 10 Claims, No Drawings CERTAIN FORMYLALKYL QUATERNARY SALTS This is a division, of application Ser. No. 819,946 filed Apr. 28, 1969 now US. Pat. No. 3,759,90l issued Sept. 18, 1973.  
  The present invention relates to organic synthesis and more particularly to a novel method of preparing reactive, N-substituted, cyclammonium quaternary salts, and to the salts prepared thereby.  
  It is an object of this invention to provide new compounds that are reactive quaternary salts of heterocyclic nuclei.  
  It is another object of the invention to provide a novel process for preparing reactive quaternary salts of heterocyclic nuclei.  
  These and other objects of the instant invention will become additionally apparent from a reading of the following specification and appended claims.  
  The objects of this invention are accomplished, in one aspect, with heterocyclic quaternary salts comprising a heterocyclic nucleus containing a heterocyclic ring of from to 6 atoms including a quaternary nitrogen atom which has substituted thereon a radical having the formula (CH-,),,R wherein:  
 a. n represents a positive integer having a value of from 2 to about 6, and  
 b. R represents a member selected from:  
 l. a formyl radical, 2. a radical having the formula wherein T, and T when taken alone, each represents a member selected from an alkoxy radical and an alkylthio radical, and T, and T when taken together, represent the atoms necessary to complete a cyclic acetal selected from cyclic oxyacetals and cyclic thioacetals containing from 5 to 6 atoms in the heterocyclic acetal ring, and  
 3. a hydrazonomethyl radical.  
  The subject quaternary salts also include heterocyclic quaternary salts comprising a heterocyclic nucleus containing a heterocyclic ring of 5 to 6 atoms including a quaternary nitrogen atom and from 4 to 5 additional atoms of which from 3 to 4 atoms are carbon atoms and wherein the remaining additional atom is selected from the group consisting of carbon, nitrogen, oxygen, sulfur and selenium atoms. The quaternary nitrogen atom is substituted as described hereinabove.  
  Advantageously included within the subject invention are quaternary salts having the formula:  
 wherein:  
 a. Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing a heterocyclic ring of 5 to 6 atoms including the quaternary nitrogen atom, with the additional atoms of said heterocyclic ring being selected from carbon, nitrogen, oxygen, sulfur and selenium, b. j represents a positive integer of from 1 to 2, c. 11 represents a positive integer of from 2 to 6, d. X represents an acid anion, e. R represents a member selected from:  
 1. a formyl radical, 2. a radical having the formula wherein T, and T when taken alone, each represents a member selected from an alkoxy radical and an alkylthio radical, and T, and T when taken together, represent the atoms necessary to complete a cyclic acetal selected from cyclic oxyacetals and cyclic thioacetals containing from 5 to 6 atoms in the heterocyclic acetal ring, and  
  3. a hydrazonomethyl radical, and f. R, represents either a hydrogen atom, an alkyl radical, an alkylthio radical or an aryl radical such as phenyl and naphthyl.  
  Exemplary heterocyclic nuclei completed by those atoms represented by Z are such nuclei as, for example, an indole nucleus, an imidazole nucleus, an oxazole nucleus, a thiazole nucleus, a selenazole nucleus, or a quinoline nucleus including those of the imidazole series such as benzimidazole compounds like 5- chlorobenzimidazole and also including compounds of the naphthimidazole series; those of the thiazole series such as thiazole, 4-methylthiazole, 4-phenylthiazole, S-methylthiazole, S-phenylthiazole, 4,5- dimethylthiazole, 4,5-diphenylthiazole, 4-(2- thienyl)thiazole, etc.; those of the benzothiazole series like benzothiazole, 4-chlorobenzothiazole, 5- chlorobenzothiazole, 6-chlorobenzothiazole, 7- chlorobenzothiazole, 4 4-methylbenzothiazole, 5- methylbenzothiazole, 6-methylbenzothiazole, 5- bromobenzothiazole, 6-bromobenzothiazole, 4- phenylbenzothiazole, S-phenylbenzothiazole, 4- methoxybenzothiazole, S-methoxybenzothiazole, 6- methoxybenzothiazole, S-iodobenzothiazole, 6- iodobenzothiazole, 4-ethoxybenzothiazole, 5- ethoxybenzothiazole, tetrahydrobenzothiazole,  
 5,6-dimethoxybenzothiazole, S-hydroxybenzothiazole, 6-hydroxybenzothiazole, etc.; those of the naphthothiazole series such as a-naphthothiazole, 8-methoxy-anaphthothiazole, 7-methoxy-a-naphthothiazole, naphtho[2,l-d]thiazole, naphtho[2,3-d]thiazole, etc.; those of the thionaphtheno-7&#39;,6&#39;,4,5-thiazole series like 4&#39;- methoxythionaphtheno-7,6, 4,5-thiazole, etc.; those of the oxazole series such as 4-methyloxazole, 5- methyloxazole, 4-phenyloxazole, 4,5-diphenyloxazole, 4-ethyloxazole, 4,5-dimethyloxazole, S-phenyloxazole, etc.; those of the benzoxazole series like benzoxazole, 5-chlorobenzoxazole, S-methylbenzoxazole, 5- phenylbenzoxazole, 6-methylbenzoxazole, 5,6-dimethylbenzoxazole, 4,6-dimethylbenzoxazole, 5- methoxybenzoxazole, 5-ethoxybenzoxazole, 5- chlorobenzoxazole, 6-methoxybenzoxazole, 5- hydroxybenzoxazole, 6-hydroxybenzoxazole, etc.; those of the naphthoxazole series such as a-naphthoxazole; those of the selenazole series like 4- methylselenazole, 4-phenylselenazole, etc.; those of the benzoselenazole series like benzoselenazole, 5-  
 chlorobenzoselenazole, 5-methoxybenzoselenazole, 5-hydroxybenzoselenazole, tetrahydrobenzoselenazole, etc.; those of the naphthoselenazole series such as oz-naphthoselenazole; and those of the quinoline series such as quinoline, lepidine. etc.  
  The acid anions represented by X include a wide variety of such anions including halide anions like bromide, chloride and iodide, as well as additional anions, e.g., sulfates including sulfate, hydrosulfate, and lower alkylsulfates like methylsulfate and ethylsulfate, aromatic sulfonates such as p-toluene sulfonate and benzenesulfonate, acid anions derived from carboxylic acids like acetate, trifluoroacetate, propionate and a wide variety of other anions including anions such as, for example, perchlorate, cyanate, thiocyanate, sulfamate, benzoate, etc.  
  Of the radicals represented by R, included are formyl, radicals as described herein having the formula T1 at wherein T, and T when taken alone, each represent either an alkoxy radical typically having from 1 to about 6 carbon atoms in the alkoxy chain or an alkylthio radical preferably having from 1 to 6 carbom atoms in the alkyl chain thereof and, when taken together, represent the atoms necessary to complete a cyclic acetal which is either a cyclic oxyacetal or cyclic thioacetal radical such as 1,3-dithiolan-2-yl, 1,3- dioxolan-2-yl, 1,3-dithian-2-yl, l,3-dioxan-2-yl and the like radicals; and hydrazonomethyl radicals including such substituted hydrazonomethyl radicals as a thiosemicarbazonomethyl radical, a phenylhydrazonomethyl radical like phenylhydrazonomethyl, p-tolylhydrazonomethyl, p-sulfophenylhydrazonomethyl, p-nitrophenylhydrazonomethyl, 2,4- dinitrophenylhydrazonomethyl, a benzothiazol-Z- ylhydrazonomethyl radical, an N-phenylcarbamoylhydrazonomethyl radical and the like hydrazonomethyl radicals.  
  As employed herein, the terms alkyl radical, alkoxy radical and alkylthio radical include aliphatic, branched and straight chain alkyl, alkoxy and alkylthio radicals typically having from 1 to 6 carbon atoms in the alkyl moiety such as alkyl radicals like methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, amyl, hexyl, etc.; alkoxy radicals such as methoxy, ethoxy, propoxy, n-butoxy, tert-butoxy, and the like alkoxy radicals, and alkythio radicals like methylthio, ethylthio, tertbutylthio, hexylthio, etc. Preferably, the subject alkyl, alkoxy and alkylthio radicals have from 1 to 4 carbon atoms in the alkyl moiety thereof, and they can be substituted or unsubstituted radicals. As used herein, the term aryl radical comprehends such radicals as substituted or unsubstituted phenyl and naphthyl radicals.  
  Of the reactive cyclammonium quaternary salts described herein, especially advantageous salts include those having theformula:  
  --Zr t r (:CII-C1&#39;I)k-1 -R3 wherein:  
 a. Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus such as those described elsewhere herein as completed by 2 atoms,  
 b. k represents a positive integer of from 1 to 2,  
 c. g represents a positive integer of from I to 5,  
 d. X represents an acid anion such as those described hereinabove,  
 e. R represents either a formyl radical or a radical having the formula wherein T and T are as defined for T and T and f. R represents a substituent as defined for R Reactive quaternary salts of this invention include such compounds as:  
 3-( Z-formylethyl )-Z-methylbenzothiazolium bromide,  
 3-( 3 ,3-dimethoxypropyl )-2-ethylbenzimidazolium chloride,  
 3-(3,3-diethoxypropyl)-2-methylbenzothiazolium iodide,  
 l (2-formylethyl)lepidinium bromide,  
 l-[2-( l,3-dithian-2-yl)ethyll-Z-ethylquinolium dide.  
 3-(3,3-diethoxypropyl)-2-methylbenzothiazolium perchlorate,  
 5-chloro-3-(2-formylethyl)-2- methylbenzoselenazolium bromide,  
 3-[3,3-di(ethylthio)propyll-Z-methylbenzothiazolium iodide,  
 3-[3,3-di(ethylthio)propyl]-2-methylbenzothiazolium p-toluene sulfonate,  
 l-(2-formylethyl)lepidinium bromide,  
 3-(3-formylpropyl)-2-ethylbenzimidazonium hydrosulfate,  
 3-( 6,6-diethoxy-n-hexyl )-2-methylnaphtho[ 2, l  
 d]thiazolium bromide,  
 3-[3,3-di(methylthio)propyll-Z-methylbenzothiazolium iodide,  
 3-(2-formylethyl)-2-methylbenzoselenazolium bromide,  
 3-( 3,3-diethylthiopropyl)-2-ethylbenzoxazolium bromide,  
  3-(2-formylethyl)-5,6-dimethoxy-2-methylbenzothiazolium bromide. other useful quaternary salts of the subject invention include hydrazonoalkyl substituted salts having the formula:  
  &#34;Z2 1 1 (=OH-CH) 1=-R5 I&#39;I&#39;J 9 t JHz 2) m-l wherein:  
 a, Z; represents the non-metallic atoms necessary to complete a heterocyclic nucleus such as those described elsewhere herein as completed by Z atoms,  
 b. p represents a positive integer of from 1 to 2,  
 c; m represents a positive integer of from 1 to 5,  
 d. R represents a hydrazonomethyl radical,  
 e. R represents a substituent as defined for R and f. X represents an acid anion.  
  Exemplary hydrazonomethyl radicals useful herein are, for example, those having the formula M-N- HN=CH wherein M represents an aryl radical such as phenyl or naphthyl which can be substituted with such substituents as hydroxy, alkyl, amino radicals like alkylamino, arylamino, heterocyclic amino, alkoxy, aryloxy, such amido radicals as acyloxy amido acylcarbonamido, alkylcarbonamido, het rocyclic carbonamido, arylsulfonamide, alkylsulfonamido and heterocyclic sulfonamido.  
  Especially advantageous hydrazonoalkyl substituted quaternary salts of this invention include such salts as those described hereinabove wherein m is 1, R represents a methyl radical and R, represents a hydrazonomethyl such as:  
 . a phenylhydrazonomethyl radical,  
 . a p-tolylhydrazonomethyl radical,  
 . a p-sulfophenylhydrazonomethyl radical,  
 . a thiosemicarbazonomethyl radical,  
 . a benzothiazol-2-ylhydrazonomethyl radical, a p-carboxyphenylhydrazonomethyl radical,  
 g. a p-toluenesulfonylhydrazonomethyl radical,  
 h. a p-chlorophenylhydrazonomethyl radical,  
 i. a p-nitrophenylhydrazonomethyl radical,  
  j. an N-phenylcarbamoylhydrazonomethyl radical,  
 k. a 2,4-di(methylsulfo)phenylhydrazonomethyl radical,  
 l. a 2,4-dinitrophenylhydrazono radical, or  
 m. a 3-quinolylhydrazonomethyl radical.  
  Exemplary hydrazonoalkyl substituted quaternary salts of the invention include such compounds as, for example:  
 3-[3-(benzothiazol-2-ylhydrazono)propyll-Z-methylbenzothiazolium iodide,  
 3-l3-(p-carboxyphenylhydrazono)propyl]-2-methylbenzoxazolium chloride,  
 3-[ 3-( p-carboxyphenylhydrazono )propyl benzothiazolium bromide,  
 2-methyl-3-[3-(ptoluenesulfonylhydrazono)propyl]naphtho[2,1 d]thiazolium iodide,  
 3-[3-(p-chlorophenylhydrazono)propyl]naphtho[2,l-d]thiazolium bromide,  
 3-[ 3-( p-carboxyphenylhydrazono )propyl ]-2-ethyl- F O- UN naphtho[2,l-d]thiazolium bromide, 2-methyl-3-[(3-p-nitrophenylhydrazono)propyl]- naphtho[2,l-d]thiazolium iodide, 2-methyl-3-[3-(N- phenylcarbamoylhydrazono)propyl]naphtho[2, l d]thiazolium iodide, 3-[3-(2,4-  
  dimethylsulfonylphenylhydrazono)propyl]-2- methylnaphtho[ 2, l -d ]thiazolium bromide, 3-[3-(p-carboxyphenylhydrazono)propyl]-2- phenylbenzoselenazolium-p-toluene sulfonate, 3-[(3-phenylhydrazono)propyl]benzothiazolium carboxylate, 3-[(3-p-carboxyphenylhydrazono)propyll-2-methylbenzothiazolium bromide, 3-[(3-p-carboxyphenylhydrazono)propyl]-5-chloro- Z-methylbenzothiazolium bromide, 3-[3-(phenylhydrazono)propyl]benzothiazolium benzene sulfonate, 2-ethyl-[ 3-( 3-p-sulfophenylhydrazono )propyl ]benzothiazolium iodide, 3-[3-(p-sulfophenylhydrazono)propyl]benzothiazolium iodide, 2-methyl-3-[ 3-thiosemicarbazono )propyl]benzothiazolium bromide, 2-methyl-3-[3-(thiosemicarbazono)propyl]benzothiazolium hydrosulfate, 2-methyl-3-[(3-phenylhydrazono)propyllbenzothiazolium iodide, 2-methyl-3-[(3-phenylhydrazono)propyl]benzothiazolium thiocyanate, 2-methyl-3-[3-(p-tolylhydrazono)propyllbenzothioazolium iodide, 2-methyl-3-[3-(p-sulfophonylhydrazono)propyl]- benzothiazolium chloride, 2-methyl-3-[(3-thiosemicarbazono)propyl]benzothiazolium perchlorate, 2-methyl-3-[ 3-phenylhydrazono )propyl benzothiazolium benzene sulfonate, 2-methyl-3-[3-(p-tolylhydrazono)propyl]benzothiazolium acetate,  
 ,2-methyl-3-[ 3-( p-sulfophenylhydrazono )propyllbenzothiazolium propionate, 2-methyl-3-[3-(benzothiazol-Z-ylhydrazono)propyl]- benzothiazolium cyanate,  
 5 ,6-dichlorol -ethyl-2-methyl-3-[ 3-( psulfophenylhydrazono)propyl]benzimidazolium bromide,  
 5,6-dichloro-3-[3-(2- benzothiazolylhydrazono )propyl]- l -ethyl-2- methylbenzimidazolium bromide,  
 5,6-dichloro-2-methyl-3-[ 3-( 3- quinolylhydrazono)propyll-lethylbenzimidazolium bromide,  
 5-chloro-2-methyl-3-[ 3-( p-tolylhydrazono)propyl]- benzoselenazolium bromide,  
 2-methyl-3-[ 3-(ptoluenesulfonylhydrazono)propyl]benzothiazolium bromide,  
 2-methyl-3-[3-(p-tolylhydrazono)propyl]benzothiazolium bromide,  
 3-[ 3-( 2,4-dinitrophenylhydrazono )propyl ]benzothiazolium bromide,  
 5 ,6-dichlorol -ethyl-2-methyl-3-[ 3- )ptolylhydrazonolpropyl]benzimidazolium bromide,  
 5,6-dichloro-l-ethyl-2-methyl-3-[3-(pnitrophenylhydrazono )propyl ]benzimidazolium bromide,  
 wherein:  
 a. Z represents the atoms necessary to complete a heterocyclic nucleus such as those defined hereinabove.  
 b.j represents a positive integer of from I to 2,  
 c. d represents a positive integer having a value of from I to 5,  
 d. X represents an acid anion,  
 e. R.,- represents:  
 l. a group having the formula W -C-&#39;l wherein T represents a member selected from a hydrogen atom, a hydroxyl radical, and alkyl radical having preferably from I to 4 carbon atoms, and an alkoxy radical preferably having from 1 to 4 carbon atoms.  
 2. a sulfo radical, 3. a cyano radical, 4. an alkylsulfonyl radical wherein the alkyl moiety has from 1 to 4 carbon atoms. and 5. a radical having the formula wherein T, and T are as previously defined. and R, is as described in R,, said process comprising reacting a compound having the formula:  
  Z li (=CH-C ll) =d-R7 X 11 wherein Z. j. X and R, are as previously defined, with a compound having the formula:  
 LII  
 wherein d and R are as previously defined.  
  The reaction medium is advantageously an inert organic solvent that exhibits moderate polarity and dissolves both the acid anion and the quaternary salt reagents, but which is not a solvent for the reaction product. Exemplary of such a medium are such solvents as acetonitrile and dimethylacetamide. No reaction catalysts are generally required and the reaction temperature is conventionally variable from about 20C to about 30C, although wider reaction temperature can be employed so long as the reagents remain in solution and are not subjected to heating in excess of their decomposition temperatures. For example, reflux conditions can be employed to promote the reaction. The reaction products precipitate from solution and can then be purified by such conventional means as solvent washing or sequential crystallization from solvents such as, for example, acetone, ethers, alcohols such as methanol, ethanol and propanol, mixtures of alcohol and water, etc.  
  The subject advantageous processes also include a process for the preparation of quaternary salts having the formula:  
  1 &#34;I, I I =oHoH k ,=b-a,  
  llh l llfih-i wherein:  
 a. Z, represents the atoms necessary to complete a heterocyclic nucleus. such as defined hereinabove as represented by Z atoms,  
 b. k represents a positive integer of from 1 to 2,  
 c. b represents a positive integer of from 1 to 5,  
 d. X represents an acid anion,  
 e. R represents a member selected from a formyl radical and a radical having the formula wherein T,, and T, are as defined for T, and T and f. R,, is as previously defined,  
 said process comprising reacting a compound having the formula:  
 wherein Z,, k, X. and R are as previously defined. with a compound having the formula:  
 wherein b and R are as&#39;previously defined.  
  Particularly advantageous processes include those for preparing the salts mentioned immediately hereinabove wherein R, represents a methyl radical, X represents a halide anion and b has a value of 1.  
 Additional reactive quaternary salts prepared according to the processes of this invention are the N- hydrazonoalkyl substituted quaternary salts of the type described in detail hereinabove. The processes for preparing hydrazonoalkyl substituted salts include the process for preparing quaternarysalts having the formula:  
  --Z2 $1 (=oH-omm-1=o-R5 X H2 H2 2)el wherein:  
 a. 2 represents the atoms necessary to complete a heterocyclic nucleus such as defined hereinabove as represented by Z atoms,  
 b. m represents a positive integer of from I to 2.  
 c. c represents a positive integer of from 1 to 5,  
 d. X represents an acid anion,  
 e. R represents a hydrazonomethyl radical, and  
 f. R; is as previously defined.  
 said process comprising the steps of:  
 a. reacting a compound having the formula:  
 wherein 2:, m. R and X are as previously defined, with a compound having the formula:  
 wherein c is as previously defined and T represents an acyl radical such as a formyl radical, an acetyl radical. and a propionyl radical to prepare an intermediate compound having the formula:  
  &#34;Z2 N (=CPIGH)m-1=CR5 10 p-carboxyphenylhydrazine,  
 p-tolylsulfohydrazine,  
 p-chlorophenylhydrazine,  
 p-nitrophenylhydrazine,  
 N-phenylcarbamoylhydrazine, and  
 2,4-di( methylsulfo )phenylhydrazine.  
 , Particularly advantageous processes include those for preparing hydrazonoalkyl substituted salts such as those described hereinabove wherein R represents a methyl radical, X represents a halide anion and the hydrazonoalkyl radical represented by R, is selected from:  
 a. a phenylhydrazonomethyl radical.  
 b. a p-tolylhydrazonomethyl radical.  
 c. a p-sulfophenylhydrazonomethyl radical,  
 d. a thiosemicarbazonomethyl radical.  
 e. a benzothiazol-2-ylhydrazonomethyl radical,  
 f. a p-carboxyphenylhydrazonomethyl radical,  
 g. a p-tolylsulfohydrazonomethyl radical,  
 h. a p-chlorophenylhydrazonomethyl radical,  
 i. a p-nitrophenylhydrazonomethyl radical,  
 j. an N-phenylcarbamoylhydrazonomethyl radical,  
 k. a 2,4-di(methylsulfo)phenylhydrazonomethyl radical,  
 l. a 2,4-dinitrophenylhydrazono radical, or  
 m. a 3-quinolylhydrazonomethyl radical.  
  The conveniently prepared, reactive quaternary salts of this invention are useful as photographic addenda in silver halide photographic emulsions and especially in gelatino-silver halide emulsionsas, for example, antifoggants, etc., and as chemical intermediates in, for example, the production of photographic dyestuffs by condensation reactions. Exemplary of a typical dye condensation to prepare a symmetrical photographic sensitizing dye is the reaction of a subject quaternary salt with an excess amount (molar) of a condensing reagent such as diethoxymethyl acetate, 1,3,3-trimethoxypropene and the like. Unsymmetrical photographic dyes can be prepared by reacting the quaternary salts of this invention with a dye intermediate such as pdimethylaminobenzaldehyde, 5-acetanilidomethylene- 3-ethylrhodanine, 3-ethylmercaptobenzothiazolium ethylsulfate, etc. The dyes so prepared are useful in photographic elements either as spectral sensitizers for a photosensitive species such as silver halide or serving alternative functions wherein organic dyestuffs are advantageously employed.  
  The subject hydrazonoalkyl substituted quaternary salts are additionally advantageous as nucleating agents or fogging agents in silver halide reversal or direct positive emulsions used in positive-working photographic elements designed for reversal processing to prepare direct positive photographic images without utilizing an intermediate developed negative image. Such direct positive emulsions form latent i&#39;mages predominantly inside the silver halide grains.  
  The photographic emulsions generally used in reversal processes are gelatino-silver halide emulsions such as silver bromide, silver bromoiodide or silver chloroiodide emulsions. They need not contain sensitizing dyes although certain such dyes may be added to reversal emulsions for the purpose of inducing aerial fog, as well as to widen spectral sensitization. Internal latent image emulsions are typically undigested or if digested, the digestion is carried out without the use of surface sensitizers. An emulsion of this type, known as Burton&#39;s Heterocyclic Quaternary Salt Melting Reagent Reaction Product Point Yield -chloro-2-methyl- 5-chloro-3-( Z-formylcthyl 237- 5771 benzothiazolium 2-methylbenzothiazolium 240C hydrobromide bromide S-methoxy-Z-mc- 3-(Z-formylethylJ-S-mcthoxy- 197- 70% thylbenzothiazol- 2-methylbcnzothiazolium 198C ium hydrobromide bromide 5.6-dimethoxy-2- 5,6-dimethoxy-3-( Z-formyloil 207! methylbenzothiethyl)-2-methylbenzothiazolium hydroazolium bromide bromide Z-methylnaphtho 3-(2-formylethyl)-2-methyloil 107: [2,3-d lthiazolium naphthol 2.3-d lthiazolium hydrobromide bromide 4-methylquinolium l-( Z-formylcthyl )-4-mcthyl- 165- 7271 hydroiodidc quinolium iodide 167C emulsion is described in Wall Photographic Emu. sions,&#34; 1927, pp. 52 and 53. Further types of suitable reversal emulsions are internal latent image emulsions described in Davey and Knott. U.S. Pat. No. 2,592,250 and Luckey et al.. U.S. Pat. No. 2,996,382.  
  The following examples are included for a further understanding of the invention.  
 EXAMPLE 1 Preparation of 3-(2-formylethyl)-2-methylbenzothiazolium bromide: Z-methylbenzothiazolium hydrobromide (1 mol., 11.5 g.) and acrolein (1 mol. 150% excess, 13.5 g.) are mixed in dimethylacetamide (150 ml.) and the mixture is stirred overnight at about 22C. The pale yellow solid which forms is then collected on a filter funnel. washed with an excess of acetone and dried. The yield of crude salt is 110 g. (77%), mp. 249-250C dec.  
 EXAMPLE 2 Preparation of 5-chloro-3-(2-formylethyl)-2- methylbenzoselenazolium bromide: 5-chloro-2- methylbenzoselenazolium bromide (1 mol., 31.1 g.) and acrolein (1 mol. 100% excess, 11.2 g.) are mixed in dimethylacetamide 100 ml.) and the mixture stirred overnight at a temperature of 22C. The white solid that forms is collected on a filter funnel, washed with acetone and dried. Yield of crude salt is 33 g. (90%) EXAMPLE 3 Preparation 3 of 5.6-diehloro-l-ethyl-3-(2- formylethyl)-2-methylbenzimidazolium bromide: 5,6- dichloro-l-ethyl-2-methylbenzimidazolium hydrobromide (1 mol.. 31 g.) and acrolein (1 mol. 100% excess, l 1.2 g.) are mixed in 800 ml. dimethylacetamide, and the mixture is heated with stirring until all solids are dissolved. The heat is then removed and the solution is stirred at 22C with stirring overnight. At this point ether l l.) is added and the product precipitates from solution as a white solid. The white solid is collected on a buchner funnel, washed with ether and dried. The product is used without further purification. Yield is theoretical, m.p. 279 to 281C.  
 EXAMPLE 4 EXAMPLE 5 Preparation of 3-(3,3-diethoxypropyl)-2-methylhenzothiazolium iodide: 3-( Z-formylethyl)-2-methylbenzothiazolium iodide (1 mol., 64 g.) is suspended in absolute ethyl alcohol 150 ml.) with 30-32% hydrobromic acid in acetic acid (2 ml.) added, and the mixture is stirred at about 22C one hour. A small portion of the alcohol solution is removed and stirred with an excess 5 of ether. Ether is then decanted from the sticky residue;  
 more ether is added with stirring; ether is again decanted, and the sticky residue stirred with a small amount of acetone. The sticky residue dissolves in the acetone and the solution is treated with ether portionwise until it becomes cloudy, which cloudiness is followed by the product crystallizing from solution as a yellow solid. The main solution is then treated with the seed crystals and stirred at room temperature for one hour. The yellow crystals are then collected on a filter funnel, washed with ether and dried. The yield of pure product is 48 g. (81%), mp. ll5-l 16C with dec. at C. Using procedures similar to those of Examples 1, 2 and 3, additional compounds of this invention can be prepared conveniently by reacting a heterocyclic hydro salt reagent with additional aliphatic compounds containing activated double bond systems.  
 EXAMPLE 6 Utilizing procedures like those of Example 1. the following preparations can be conveniently accomplished:  
 a. 1 -ethyl-2-methyl-3-( 2-propionylethyl )benzimidazolium bromide is prepared by reacting lethyl-2-methylbenzimidazolium hydrobromide and ethylvinylketone,  
 b. 3-&#39;(2-cyanoethyl)-2-methylbenz0xazolium iodide is prepared by reacting 2-methylbenzoxazolium hydroiodide and acrylonitrile.  
 c. 2-propyl-3-(2-carboxyethyl)naphtho[2.3-  
  dlselenazolium chloride is prepared by reacting 2- propylnaphthol2.3-d[selenazolium hydrochloride and acrylic acid.  
 d. 3-[ 3.3-di(ethylthio )propyl1-2-methylbenzothiazolium hydrosulfate is prepared by reacting Z-methylbenzothiazolium hydrosulfate and vinyldi- (ethylthio )methane-[ 3.3-di( ethylthio )propl -ene],  
 e. 3-[2-( l .3-dithiolan-2-yl)ethyll-2-ethylbenzothiazolium iodide is prepared by reacting 2-ethylbenzothiazolium hydroiodide and 1,3-dithiolan-2- ylethylenc.  
 Additional reactive quaternary salts can be prepared &#39;in a similar fashion.  
  As described hereinabove, the subject hydrazonoalkyl substituted quaternary salts are advantageous as nucleating (fogging) agents in silver halide reversal emulsions. Conventionally, those salts are reducing agents due to the presence of reactive substituents such as hydrazine derivatives. Exemplary preparations are described as follows.  
 EXAMPLE 7 Preparation of 2-methyl-3-thiosemicarbazonopropyl benzothiazolium bromide: thiosemicarbazide 1 mol. I071 excess, l g.) is dissolved in a refluxing solution of equal parts ethyl alcohol and water (150 ml.), and 3-(2-formylethyl)-2-methylbenzothiazolium bromide prepared according to the procedure of Example 1 is added, and all solids are dissolved. Concentrated sulfuric acid (4 drops) is then added, and the entire solution is stirred for one-half hour. The solution is then chilled with stirring by means of an ice bath and after several minutes, the product separates from solution as an oil that quickly becomes crystalline. The light tan crystals are collected on a filter funnel, washed with acetone and dried. The yield of crude product is 20 g. (56% m.p. l77-l78C.  
 EXAMPLE 8 Preparation of 2-methyl-3-(3- phenylhydrazonopropyl)benzothiazolium bromide: 3- (2-formylethyl)-2-methylbenzothiazolium bromide (1 mol., 14.3 g.), as described in Example I, is partially dissolved in ethyl alcohol 100 ml.) with stirring. Phenylhydrazine (1 mol. 10% excess, l 1.9 g.) is added followed by the addition of concentrated sulfuric acid (4 g.) are dissolved in water 100 ml.) with stirring. After stirring at about 22C one minute the product crystallizes from solution. The mixture is stirred at about 22C for 15 minutes, and the crystalline salt is collected on a filter funnel, washed well with an excess of water and dried. After one recrystallization from a mixture of methyl alcohol and water in a 1:1 ratio, the yield of product is 11 g. (56%), m.p. 163l64C.  
 EXAMPLE 10 Preparation of 2-methyl-3-(psulfophenylhydrazonopropyl)benzothiazolium bromide: 3-(2-formylethyl)-2-methylbenzothiazolium bromide (1 mol., 14.3 g.), as prepared in Example 1, is dissolved in water (200 ml.) with stirring, then gravity filtered and treated with a suspension of p-hydrazino-benzene-sulfonic acid (1 mol., 9.4 g.) in water (400 ml.) with stirring. After minutes of stirring at about 22C., a buff colored solid precipitates from solution. After the entire solution has stirred at the 22C temperature, the solid is collected on a filter funnel, washed with an excess of water and dried. The product is then stirred with refluxing methyl alcohol (500 ml.) collected on a filter funnel and dried. The  
 yield of product is 20 g. (87%), m.p. 258-259C.  
 EXAMPLE l 1 Preparation of 2-methyl-3-( benzothiazol-2- ylhydrazonopropyl)benzothiazolium bromide: 3-(2- formylethyl)-2-methylbenzothiazolium bromide (1 mol., 14.3 g.), as prepared in Example 1, and 2- hydrazinobenzothiazole (1 ml., 8.15 g.) are mixed in ethyl alcohol (150 ml.) with stirring at about 22C. Concentrated sulfuric acid (4 drops) is added while methylbenzimidazolium hydrobromidc and 3- hydrazinoaquinolinc propylll -ethylbcnzimidazolium bromide drops), and the mixture is Stirred at about 22 f 15 stirring is continued, and the entire mixture is stirred at minutes. At this point, heat is applied, the mixture is about Thefnlxture heated to f heated to reflux temperature with stirring and the prod- Perature f u fi g, and ltile plrodulctj precrlrirtateg uct is crystallized from solution as a white solid. The from Sohmon as whlte :9 e T z solid is collected on a filter funnel, washed with ethyl 40 from t g f 5 wasde l alcohol and dried. After one recrystallization from waexcess y c0 0 an 6 pm uc en the yield of product is 10 g (53%) m p refluxed in ethyl alcohol (200 ml.) collected on afilter o oc funnel and dried. Yield of white solid is 16 g. (90%),  
 &#39; m.p. l60l6lC with dec.  
  EXAMPLE 9 EXAMPLE 12 Preparation of y -P- Utilizing procedures like those described in Examtolylhydrazon propyl) z h li bromide: ples 741, additional hydrazonoalkyl substituted quaformylethyl)-2methylbenZ0thiaZOlium bromide l ternary salts are prepared. The reagents, reaction prod- 143 g.). as pr p e in Ex mp and P- ucts,yield and melting points are summarized below in tolylhydrazine hydrochloride (1 mol. 10% excess, 8.7 b l f Reaction Melting Reagents Product Point Yield 5 ,o-dichlorol -cthyl- 5 ,6-dichloro l -ethyl-2- 289- 4071 3-(2-formylethyl)-2- methyl-3-[3-(p-sulfo- 290C methylbenzimidazolium phenylhydrazono )propyl] dec. hydrobromide and pbenzimidazolium bromide sulfophenylhydrazine 5,6-dichlorol -cthyl- 5.6-dichloro-3-l 3-( 2- 39% 3-( Z-formylcthyl )-2- bcnzothiazolylhydrazono) l4 1 C methylhcnzimidazolium propyl ll -ethyl-2-methyldec. hydrobromidc and 2- henzimidazolium bromide henzothiazolylhydra- Zine 5,6-dichlorol -cthyl- 5,b-dichloro-Z-mcthyl-fl- 191-- 3-( Z-formylethyl )-2- [34 3-quinolylhydrazono) l92C. 25%  
  The invention has been described in detail with particular reference to preferred embodiments thereof, but, it will be understood that variations and modifications can be effected within the spirit and scope of the invention. I  
 We claim:  
 1. A quaternary salt having the formula:  
 wherein:  
 a. Z, represents the atoms necessary to complete a heterocyclic nucleus selected from the group consisting of an indole nucleus, an imidazole nucleus, an oxazole nucleus, a thiazole nucleus, a selenazole nucleus and a quinoline nucleus,  
 b. k represents a positive integer of from 1 to 2,  
 c. g represents a positive integer of from 1 to 5,  
 d. X represents an acid anion,  
 e. R represents a formyl radical, and  
 f. R represents a member selected from the group consisting of a hydrogen atom, a C C,, alkyl radical, a C -C alkylthio radical phenyl and naphthyl.  
 2. A quaternary salt having the formula:  
  CH X9 (=eH-CH) 3 wherein:  
 a. 2 represents the atoms necessary to complete a heterocyclic nucleus selected from the group consisting of an indole nucleus, an imidazole nucleus, an oxazole nucleus. a thiazole nucleus, a selenazole nucleus and a quinoline nucleus,  
 b. 1 represents a positive integer of from 1 to 2.  
 c. X represents a halide anion, and  
 d. R- represents a formyl radical.  
 3. 3-(2-Formylethyl)-2-methylbenzothiazolium bromide.  
 4. 5-Chloro-3-(2-formylethyl)-2- methylbenzoselenazolium bromide.  
 5. 5.6-Dichloro-l-ethyl-(2-formylethyl)-2- methylbenzimidazolium bromide.  
 6. 5-Chloro-3-( 2-formylethyl )-2-methylbenzothiazolium bromide.  
 7. 3-(2-Formylethyl)-5-methoxy-2-methylbenzothiazolium bromide.  
 8. 5,6-Dimethoxy-3-(2-formylethyl)-2-methylbenzothiazolium bromide.  
 9. 3-(2-Formylethyl)-2-methylnaphtho[2,3-  
 dlthiazolium bromide.  
 10. 1-(2-Formylethyl)-4-methylquinolium iodide.