Process for producing sulfoalkyl-substituted hydroxylamines

Abstract: There is provided a process for producing sulfoalkyl-­ substituted hydroxylamines useful as preservatives to be added to a color developer for photosensitive materials. In this process, the sulfoalkyl-substituted hydroxylamines can be easily synthesized by reacting a specified alkylating agent, cyclic sulfonic ester, vinylsulfonic acid or sulfoalkyl-­ substituted acrylamide with a hydroxylamine.

Description: The present invention relates to a process for producing sulfoalkyl-substituted hydroxylamines useful as an additive for a photographic processing solution. Although sulfoalkyl-substituted hydroxylamines are useful as a preservative to be added to a color developer for photosensitive materials such as photographic sensitive materials, no process for their production is disclosed in the literature. It is thus desirable to develop a new technique of producing them on an industrial scale. In particular, the development of a process for easily synthesizing the sulfoalkyl-substituted hydroxylamines from readily available starting materials is eagerly desired. The following three processes are possible for synthesizing hydroxylamines: (1) a process wherein an amine compound is oxidized, (2) a process wherein an N-oxide of a tertiary amine is thermally decomposed (diethylhydroxylamine is synthesized on a large scale by this process) and (3) a process wherein an unsubstituted hydroxylamine or monosubstituted hydroxylamine is alkylated to form a monosubstituted or disubstituted hydroxylamine. US-A-3 778 464 and GB-A-1 263 199 disclose the preparation of sodium 3-(N-n-propyl-N-hydroxyamino)propane sulfonate, wherein N-propylhydroxylamine is reacted with propane sultone. DE-A-1 543 651 reveals a process for the preparation of N,N-disubstituted hydroxylamine-o-alkyl (or alkaryl)-sulfonic acids. Thereby an N,N-disubstituted hydroxylamine is reacted with sultones. GB-A-1 264 020 discloses the preparation of 3-(N-propyl-N-hydroxyamino)propionamide starting from propylhydroxylamide and acrylamide. Summary of the Invention Through an investigation into the production of sulfoalkyl-substituted hydroxylamines by these processes, the inventor found that, unexpectedly, side reactions are relatively slight in the process (3) and this process is suitable for the mass production. In particular, the inventor found that sulfoalkyl-substituted hydroxylamines can be easily synthesized by reacting a vinylsulfonic acid, which is readily available on the market, with a hydroxylamine. The present invention has been completed on the basis of this finding. The present invention provides a process for producing a sulfoalkyl-substituted hydroxylamine of the general formula (I): wherein L₁ represents an alkylene group, R represents a hydrogen, alkyl group or group of the formula: -L₁-SO₃M, M being a cation, which comprises reacting a hydroxylamine of the general formula (II): wherein R' represents a hydrogen or an alkyl group with a compound of the following general formula (III): wherein R₁ to R₃ each represent a hydrogen atom or alkyl group. Description of the Preferred Embodiments L₁ in the above formula is an unsubstituted or substituted alkylene group. M is preferably a hydrogen atom, alkali metal or ammonium salt. The alkyl group of R, R' and R₁ to R₃ may be either straight chain or branched and either unsubstituted or substituted. The alkyl group has preferably 1 to 10 carbon atoms. R₁ to R₃ may be the same or different from one another. A may have a substituent. A detailed description will be made on the compounds of the general formulae (I), (II) and (III) in the present invention. L₁ represents a substituted or unsubstituted alkylene group. The alkylene group is a substituted or unsubstituted, straight chain or branched alkylene group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms. The substituents include hydroxyl group and carboxyl group. M represents a hydrogen atom, alkali metal (lithium, sodium or potassium) or ammonium salt. R represents a hydrogen atom or substituted or unsubstituted alkyl group. The substituents include sulfo group, hydroxyl group, carboxyl group and carbamoyl group which may be substituted with a sulfoalkyl group. R is preferably a hydrogen atom, unsubstituted alkyl group, sulfo group or alkyl group substituted with a carbamoyl group which may be substituted with a sulfoalkyl group. R₁, R₂ and R₃ may be the same or different from one another and each represents a hydrogen atom or substituted or unsubstituted alkyl group. A preferred example of R₁, R₂ and R₃ is hydrogen atom. Examples of the sulfoalkyl-substituted hydroxylamines of the general formula (I) which can be synthesized by the process of the present invention are given below, which by no means limit the present invention: (1) HO-NH-CH₂CH₂-SO₃H (2) HO-N (CH₂CH₂-SO₃H)₂ (3) A detailed description will be made on the process of the present invention: Synthesis process wherein a compound of the general formula [III] is used: This process comprises an addition reaction of a hydroxylamine with a vinylsulfonate. A preferred example of the vinylsulfonic acids is unsubstituted vinylsulfonic acid. In the synthesis of a monosubstituted hydroxylamine by a substitution reaction of an unsubstituted hydroxylamine, the production of a disubstituted product must be inhibited. The amount of the unsubstituted hydroxylamine used is preferably 1 to 10 mol, more preferably 3 to 10 mol, per mol of the vinylsulfonic acid. In the synthesis of a disubstituted hydroxylamine by the addition reaction of an unsubstituted hydroxylamine, the amount of the vinylsulfonic acid is preferably 1 to 2.5 mol, more preferably 1.2 to 2.0 mol, per mol of the starting hydroxylamine. This process is superior to other processes in that the side reaction to form a trisubstituted product occurs only slightly and the yield of the intended product is high. The reaction solvent must be such that the starting material is soluble therein. It is preferably a mixture of water with another solvent or water alone. The reaction temperature ranges from 0°C to 100 °C. It is preferably as low as possible within the range of temperatures at which the reaction proceeds. The procedure of the reaction can be known from NMR or the like. The product can be isolated in the form of an alkali metal (sodium or potassium) salt of sulfonic acid or as betaine. If necessary, an ion exchange resin is usable. The following Examples will further illustrate the present invention. Example 1 10 g of hydroxylamine hydrochloride and 5.8 g of sodium hydroxide were added to 142 g of 25% aqueous solution of sodium vinylsulfonate. They were heated under reflux for 3 h. The reaction liquid was concentrated under reduced pressure. 100 ml of concentrated hydrochloric acid was added thereto and the mixture was heated to 50 °C. The insoluble matter was taken out by filtration. 200 ml of methanol and 100 ml of isopropyl alcohol were added to the filtrate to obtain 25.9 g (yield: 70%) of monosodium salt of the intended product [compound (2)] in the form of crystals. ¹H NMR spectrum (D₂O) δ 3.8 to 4.0 (4H, br), 3.4 (4H, t, J=7.0). Example 2 468 g of 25% aqueous solution of sodium vinylsulfonate was added to 33 g of 50% aqueous solution of hydroxylamine hydrochloride. They were heated under reflux for 2 h. 2500 ml of methanol was added to the resultant to obtain 96.0 g (yield: 73%) of disodium salt of the intended product [compound (2)] in the form of crystals. ¹H NMR spectrum (D₂O) δ 3.0 to 3.4 (8H, br)

Claims: A method for producing a sulfoalkyl-substituted hydroxylamine of the general formula (I): wherein L₁ represents an alkylene group, R represents a hydrogen, alkyl group or group of the formula -L₁-SO₃M, M being a cation, which comprises reacting a hydroxylamine of the general formula (II): wherein R' represents a hydrogen or an alkyl group with a compound of the following general formula (III): wherein R¹ to R³ each represent a hydrogen atom or alkyl group. A method of claim 1 wherein L₁ represents an alkylene group including 1 to 10 carbon atoms. A method of claim 1 wherein the alkyl group of formulae (I), (II) and (III) has 1 to 10 carbon atoms. A method of claim 1 wherein an amount of a compound of the general formula (II) wherein R' is a hydrogen is 1 to 10 mol, per mol of a compound of the general formula (III) to prepare a compound of the formula (I) wherein R is hydrogen. A method of claim 1 wherein an amount of a compound of the general formula (III) is 1 to 2.5 mol, per mol of a compound of the general formula (II) wherein R' is a hydrogen to prepare a compound of the formula (I) wherein R is L₁-SO₃M. A method of claim 1 wherein there is used a reaction solvent in which a compound of the formulae (II) and (III) is soluble therein. A method of claim 1 wherein the reaction is carried out at a temperature of 0 to 100°C.

Inventors: MORIMOTO KIYOSHI C O FUJI PHOT, MORIMOTO KIYOSHI, MORIMOTO KIYOSHI, C/O FUJI PHOTO FILM CO., LTD.
Applicants: FUJI PHOTO FILM CO LTD, FUJI PHOTO FILM CO., LTD.
Application year: 1990
Main classification: C07C303
IPC codes: C07C309, C07C303