ALDONAMIDES AND THEIR USE AS SURFACTANTS

Abstract: Aldonamide surfactants, both monosaccharide aldonamide and higher (di- or oligo-)saccharide aldoamides, containing heteroatoms (preferably O, but also S or NH) in the hydrocarbon radical, are useful as surfactants and foaming agents. These compounds exhibit superior foaming and enhanced solubility compared to their counterparts containing no heteroatoms in the hydrocarbon radical.

Description: ALDONAMIDES AND THEIR USE AS SURFACTANTS FIELD OF THE INVENTION The present invention relates to the use as surfactants and foaming agents of specific aldonamide compounds which are higher foaming and more soluble relative to other aldonamide compounds. More particularly, the invention relates to aldonamide compounds having a heteroatom (e.g. sulphur, oxygen, nitrogen) in the aliphatic hydrocarbon radical. BACKGROUND AND PRIOR ART An aldonamide is defined as the amide of an aldonic acid (or aldonolactone) , and an aldonic acid, in turn, is defined as a sugar substance (eg any cyclic sugar) in which the aldehyde group (generally found at the C. position on the sugar) has been replaced by a carboxylic acid which upon drying cyclises to an aldonolactone. Aldonamides may be based on compounds comprising one saccharide unit (eg ribonamides, gluconamide, glucoheptonamide) , two saccharide units, (eg lactobionamide or maltobiona ide) or they may be based on compounds compromising more than two saccharide units as long as the polysaccharide has a terminal sugar unit with an aldehyde group available for oxidation to a carboxylic acid group. Most surfactants presently used in personal product and in detergent compositions are based on petrochemicals. Because of increased concern over environmental issues raised by use of such materials and also because of the continually rising costs of petrochemicals, it would be advantageous to develop surfactants which are instead derived from agriculturally grown materials such as carbohydrates. These natural occurring compounds represent a source of renewable raw materials that are synthetically versatile, inexpensive, optically pure and environmentally friendly. In addition, it is most desirable to have surfactants that foam well and are readily soluble in aqueous compositions. There are a number of prior art references which are directed to N-alkyl glucona ides. US 2 662 073 (Mehltretter/US Secretary of Agriculture) , for example, teaches a gluconamide compound: 0 II HOCH 2 (CHOH) 4 CNHR in which R is a hydrocarbon radical selected from aliphatic radicals having 8 to 18 carbons, cycloaliphatic radicals having 8 to 18 carbons and rosin radicals. The compounds are said to be valuable wetting agents for use in the mercerisation of cotton and in the manufacture of viscose yarn. There is clearly no teaching or suggestion of the use of these compounds in detergent or personal product compositions nor is there a teaching or suggestion of using heteroatoms in the hydrocarbon radical (R group) to enhance water solubility. US 2 721 211 (Buc/GAF Corporation) teaches alkyl formyl phenylene glucamides as solubilising agents for vat dyestuffs. The alkyl, formyl, phenyleneamine hydrocarbon radical (R group) of these compounds are structurally unrelated to the compounds of the invention which contain a hydrocarbon radical interrupted by a heteroatom. Fieser et al in J Am Chem Soc 78. : 2825 (1956) teach the preparation of a series of N-alkyl arabonamides and N-alkyl gluconamides for use as emulsifiers. In these compounds the attached alkyl R group is 10 ~ C 1 8" Tne reference teaches that the compounds were insufficiently water-soluble to be useful as emulsifying agents. Furthermore, when oxygen was added to the compound in the form of an additional hydroxyl group on the sugar (ie alkyl glucoheptona ides) , the compound had decreased water solubility and poorer emulsifying properties. Thus, the reference suggests that the addition of oxygen in the form of a hydroxyl group in the sugar head group does not enhance water solubility. Also, there is clearly no teaching or suggestion that the addition of oxygen or other heteroatoms in the alkyl radical can enhance solubility. The fact that monosaccharide aldonamides (eg N-alkyl gluconamides) where the alkyl group is C 1Q or greater have poor water solubility (i.e., poor emulsifiers) is also recognised in DE 2 321 752 and DE 2 338 087 (Che ische.Werke Albert) . Specifically, DE 2 321 752 is directed to N,N-dialkyl polyhydroxyamide compounds having the formula: 0 II H0-CH 2 -(CHOH) CNR^ wherein R 1 is an linear or branched aliphatic radical having 4 to 7 carbon atoms, optionally interrupted by oxygen, sulphur, or hydroxyl. Since these compounds are not surface active, they cannot be used as surfactants. DE 2 330 087 broadens the patent application to cover cases where R χ may be c 8 ~ c 10/ preferably 8. The principal patent (DE 2 321 752) , however, teaches that it is impossible to prepare stable emulsions with N-alkyl aldonamides wherein the alkyl group is N-lauryl (12 carbons) , N-cetyl (16 carbons) or N-stearyl (18 carbons) . FR 2 523 962 (Centre Nationale de Recherche) teaches the compound: HO-CH in which is 2 to 6 and R is a linear or branched alkyl group containing 6 to 18 carbons. The patent further teaches polyoxyethylene, polyoxypropylene or polyglycerol derivatives of the formula. Again, however, there is no teaching that the hydrocarbon radical (R group) may be interrupted by a heteroatom in a way that would make it more soluble relative to an uninterrupted compound. JP 01 168 653A (Lion) again recognises that the monosaccharide aldonamides of the art (eg N-alkyl gluconamides) do not readily dissolve in water and do not show sufficient surface activity. Again, there is a recognition that such compounds are not readily water soluble and are therefore not useful surfactants. The Japanese patent publication seeks to address this problem by using N,N-dialkyl polyhydroxy amide compounds where one N-alkyl group is C--C 18 and the other is C 1 ~C.. There is no teaching or suggestion of using a hydrocarbon radical interrupted by a heteroatom to enhance solubility. US 4 973 473 (Revlon Inc/Schneider et al) teaches skin treatment compositions in which the primary moisturising agent can be a gluconamide. The only example of such ingredient given is the methoxypropyl gluconamide of Example 1 which has the formula: 0 II HOCH 2 (CHOH) 4 CNH(CH 2 ) 3 OCH 3 Since these compounds are clearly not surface active, they cannot be used as surfactants. There is no suggestion to utilize alkyl chains greater than methyl and there is clearly no teaching or suggestion that aldonamides containing interrupted long alkyl chains unexpectedly provide much better solubility than their non-interrupted counterparts. Hoppe-Seyler's Z Physiol Chem 330 : 182 (1963) teaches alkyl gluconyl glycinate compounds as follows: O 0 II II H0CH 2 (CHOH) 4 CNHCH 2 COR, wherein R = C. to C 1Q . While this paper does teach monosaccharide aldonamides containing an alkyl group interrupted with an ester functionality, there is no teaching or suggestion that such alkyl groups may be interrupted with, for example, ether oxygen, sulphur or amine, or that the use of such groups will provide superior solubility of the compound relative to the use of other groups. Further, there is clearly no teaching or suggestion, as with any of the above-identified references, that the use of a two-saccharide unit or greater together with an interrupted alkyl group will provide even greater solubility. Geyer, Che ische Berichte 9 : 2271 (1964) , describes the preparation of N-alkanoyl, N-gluconoyl ethylene diamine compounds having the structure (R = C 15 , C g ) : Pfannemuller et al. Chemistry and Physics of Lipids 37. : 227 (1985) , describes the preparation of N-alkanoyl-N-methyl-N'-gluconoyl ethylene diamine having the structure (R = C β ) : 0 0 II II H0CH 2 (CHOH) 4 CNHCH 2 CH 2 NCR. CH 3 These references teach monosaccharide aldonamides containing an alkyl group that is interrupted with an amide. Again, there is no teaching or suggestion that aldonamides containing alkyl groups interrupted with an ether oxygen, sulphur or amine linkage or that some interrupting groups provide greater solubility than others. Further, there is again clearly no teaching or suggestion that using sugar compounds having two saccharide units or greater (eg lactobionamides) together within an interrupted alkyl group will provide even greater solubility. Finally, there are several references teaching aldobionic compounds (ie compounds having two or more saccharide units) generally, but which are otherwise unrelated to the specific compounds of the invention. US 2 752 334 (Walton/National Dairy Research Laboratories) and US 2 785 152 (Jones/National Dairy Products Corporation) teach compounds which are the reaction products of aldobionic acids (eg lactobionic acid) and aldobionolactones with fatty amines or esters of a ino acid. The compounds are said to be useful as emulsifiers in food compositions. There is no teaching or suggestion that some lactobionamides have superior properties relative to others and certainly no teaching or suggestion that the use of a heteroatom (eg oxygen, nitrogen or sulphur) in the aliphatic hydrocarbon radical provides superior foaming and solubility relative to lactobionamides having no heteroatom in this radical. In Williams et al. Archives of Biochem and Biophysics 195(1) : 145-151 (1979) , there is described glycolipids prepared by linking aldobionic acids to alkylamine through an amide bond. There is no teaching or suggestion in this reference that the alkyl group of the alkylamine may contain a heteroatom; nor is there any teaching or suggestion that the use of such a heteroatom would provide lactobionamides having enhanced foaming and solubility relative to lactobionamides without a heteroatom. Accordingly, it would be greatly desirable to find a class of aldonamides (both single saccharide compounds or compounds with two saccharide units or greater) which can be successfully used as surfactants in, for example, personal product, dental and detergent compositions, and which also exhibit enhanced foaming and solubility. Our copending European Patent Applications EP 550 281A and EP 550 278A, filed on 30 December 1992, claiming the priority date of 31 December 1991, and published on 7 July 1993, are directed to the use of aldobionamide surfactants in personal products and in fabric washing detergent compositions. DEFINITION OF THE INVENTION The present invention accordingly provides the use of a saccharide aldonamide compound of the general formula I: wherein S represents a mono-, di- or oligosaccharide unit, A represents H, a C 1 -C 8 hydrocarbon radical, or X represents H or a C--C 4 alkyl group, Y represents a group or atom selected from O 0 0 0 (I M II II -0-, -S-, -NH-, -C-0-, -0-C-, -NH-C-, -C-NH-, R represents a straight or branched C D or above hydrocarbon radical optionally containing a substituted or unsubstituted aromatic or cycloaliphatic radical, m is an integer from 1 to 4, p is 0 or an integer from 1 to 10, as a surfactant or foaming agent in a surface-active and/or foaming composition. The invention further provides a detergent composition comprising a detersive and/or foaming amount of an saccharide aldonamide compound as defined in the previous paragraph. The invention further provides, as novel compounds, two subclasses of compounds within the general formula I: (a) a monosaccharide aldonamide compound of the formula la. wherein S. represents a monosaccharide unit of the formula wherein n represents an integer of from 1 to 6, A represents H, a C. -C- hydrocarbon radical , or X represents H or a C 1 ~C 4 alkyl group, Y- represents -0-, -S- or -NH-, R represents a straight or branched Co 0 or above hydrocarbon radical optionally containing a substituted or unsubstituted aromatic or cycloaliphatic radical, m is an integer from 1 to 4, p is 0 or an integer from 1 to 10; and (b) a di- or oligosaccharide aldonamide compound of the formula lb, wherein S_ represents a di- or oligosaccharide unit of the formula HO-CH -CH--CH—CH--CH— OH OG OH OH wherein G represents a mono-, di- or oligosaccharide unit, A represents H, a C.-C- hydrocarbon radical, or X represents H or a C.-C 4 alkyl group, Y represents a group or atom selected from O O 0 0 II If II II -0-, -S-, -NH- -C-0-, -0-C-, -NH-C-, -C-NH-, R represents a straight or branched C or above hydrocarbon radical optionally containing a substituted or unsubstituted aromatic or cycloaliphatic radical, is an integer from 1 to 4, p is 0 or an integer from 1 to 10. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a class of environmentally friendly nonionic surfactants known as aldonamides. In particular, the invention relates to specific classes of aldonamide surfactants having enhanced foaming and solubility characteristics relative to other aldonamides. The invention encompasses the use as surfactants and foaming agents of a defined class of aldonamide surfactants which have superior foaming and solubility characteristics relative to other aldonamides (eg both monosaccharide aldonamides and disaccharide aldobionamides) . Within that defined class, two specific embodiments of the invention relate to novel subclasses of aldonamides, and these are also claimed as novel compounds. In general, an aldonamide is defined as the amide of an aldonic acid or aldonolactone and an aldonic acid, in turn, is a sugar substance (eg any cyclic sugar) wherein the aldehyde group (generally found at the C-, position of the sugar) has been replaced by a carboxylic acid, which cyclises to an aldonolactone upon drying. Since an aldonamide is defined by the terminal sugar, an aldonamide may be based on compounds comprising one saccharide unit (eg ribonamides, gluconamides, glucoheptonamides) , two saccharide units (eg lactobionamides or maltobiona ides) or they may be based on compounds comprising more than two saccharide units, as long as the terminal sugar in the polysaccharide has an aldehyde group which may be converted to an aldonic acid or aldonolactone. While not wishing to be bound by theory, it is believed that the amphiphilic nature of alkyl aldonamides and aldobionamides cause them to concentrate at the surface interface thereby reducing the free energy of the system. However, when all available interfaces are saturated, the overall energy reduction may be through precipitation or soluble micelle formation. In general, the preferred interfacial phenomenon is micellisation since detergency and solubilisation of alkyl aldonamides in detergents and personal products depend on the existence of these aggregates in solution. It is also favourable for micellisation to occur at low Krafft temperatures, since alkyl aldonamides that lack a heteroatom in the hydrocarbon chain have an unfavourable heat of hydration and often precipitate out of solution rendering them ineffective. We have found that the addition of heteroatoms such as oxygen, nitrogen or sulphur unexpectedly reduced the packing constraints of these materials in the solid state. The net result is a more favorable heat of hydration, a lower Krafft point, enhanced rate of micellisation and superior foaming. Also closer observation will reveal that compounds of this invention also unexpectedly allow the introduction of the same or greater alkyl chain length (differing only by the presence of the heteroatom) without simultaneously sacrificing foaming and solubility characteristics. The aldonamides and aldobiono ides used in the composition of the invention have solubilising and foam stabilising properties which are superior to aldonamides and aldobionamides having no heteroatom in the hydrocarbon radical. Preferred compounds used in the invention In all compounds that are used in accordance with the invention, the A group is preferably hydrogen although it may be a C 1. to Co- straight chain or branched chain, saturated or unsaturated hydrocarbon. When A is a C- to C g hydrocarbon radical, it may be straight chain or branched, saturated or unsaturated aliphatic; aromatic; mixed aromatic/aliphatic. The A group may also be interrupted by a heteroatom and may have the same structure as the other monosaccharide group attached to the nitrogen. If this A group is an aliphatic radical, suitable aliphatic hydrocarbon radicals include saturated and unsaturated radicals including but not limited to methyl, ethyl, amyl, hexyl, heptyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl, and allyl, undecenyl, oleyl, linoleyl, linolenyl, propenyl, and heptenyl. If the A group is an aromatic group, the aromatic radical may be, for example, benzyl. Suitable mixed aliphatic aromatic radicals are exemplified by benzyl, phenyl ethyl, and vinyl benzyl. R may be a straight or branched chain, saturated or unsaturated hydrocarbon backbone which may contain a substituted or unsubstituted aromatic radical or cycloaliphatic radical, wherein the hydrocarbon backbone comprises 8 or more carbon atoms. Novel compounds of the invention In a first embodiment, the invention relates to a class (a) of single saccharide unit compounds of the formula la above (eg gluconamides) having an ether group, sulphur atom or amine in the aliphatic hydrocarbon radical. In a second embodiment, the invention relates to a class (b) of compounds having two saccharide units or greater, of the formula lb above, with a more broadly defined class of heteroatom in the aliphatic hydrocarbon radical. The monosaccharide aldonamides (a) These compounds may be represented by the general formula below, which is equivalent to formula la given above: wherein n, A, m, Y_, p and R have the meanings given previously. Preferred examples of monosaccharide aldonamides in accordance with the invention include C„ to C 15 oxypropyl D-gluconamides and C.- to C-. aminopropyl D-gluconamides. A specific example is dodecyl oxypropyl gluconamide having the structure above wherein n = 4, X = hydrogen, m = 3, Y = oxygen, p = 0, A = hydrogen, and R = C χ2 straight chain alkyl. The di- or oligosaccharide aldonamides fb) The greater than one saccharide unit aldobionamides may be represented by the following the general formula, which is equivalent to the formula lb given above: wherein G, A, X, m, Y, p and R have the meanings given previously. It will be noted that Y has a broader meaning than Y. and can represent any of the following atoms or groups: NH, 0, S, G is an attached saccharide unit(s) (mono-,di- or oligosaccharide) . Preferred examples of disaccharide aldobionamides in accordance with the present invention include C..- and C.. oxypropyl lactobionamides, D-lactobionyl C 12 ~beta alanate, and D-lactobionyl C 12 glycinate. A specific example of an aldobionamide which may be used for the purposes of the invention is the disaccharide dodecyl oxypropyl lactobionamide having the formula wherein X = hydrogen; m (1st m from left to right) = 3; Z = oxygen; p = 0; A = hydrogen; and R = C- 2 straight chain alkyl. DETERGENT COMPOSITIONS The novel detergent components of the present invention may be incorporated in detergent compositions of all physical types, for example, powders, liquids, gels and solid bars. They may, for example, be incorporated at low levels to enhance the foam of other detergent-active compounds, or in more substantial amounts as surfactants in their own right. These compositions may generally contain other detergent-active compounds, detergency builders, bleaching components and other active ingredients to enhance performance and properties. Other detergent-active compounds (surfactants) present may be chosen from soap and non-soap anionic, cationic, nonionic, amphoteric and zwitterionic detergent-active compounds, and mixtures thereof. Many suitable detergent-active compounds are available and are fully described in the literature, for example, in "Surface-Active Agents and Detergents", Volumes I and II, by Schwartz, Perry and Berch. The preferred detergent-active compounds that can be used are soaps and synthetic non-soap anionic and nonionic compounds. Detergent compositions of the invention may also, depending on the purpose for which they have been formulated, contain various ancillary ingredients. For example, fabric washing compositions may contain detergency builders; bleach components; sodium carbonate; sodium silicate; antiredeposition agents such as cellulosic polymers; fluorescers; inorganic salts such as sodium sulphate; proteolytic and lipolytic enzymes; dyes; coloured speckles; perfumes; fabric softening compounds. This list is not intended to be exhaustive. The compounds of the invention are also suitable for other applications in which surfactant and/or foaming properties are useful, for example shampoos and personal washing, personal care and dental care compositions. EXAMPLES The invention is set forth in greater detail in the examples which follow below. These examples are intended to be illustrative only and are not intended to be limiting in any way. Example 1 Preparation of coco D-σluconamide (used for comparative purposes) A 5-litre four-necked round bottom flask equipped with a condenser, addition funnel, thermometer and mechanical stirrer was charged with D-glucono-l,5-lactone (480 g, 2.69 moles) and methanol (2752 g, for 27% total solids) . The suspension was heated to 40-50°C for 15 minutes and the heating mantle removed. Cocoamine (538 g, 2.69 moles) containing methanol (80 ml) was added dropwise over 1/2 hour. The reaction mixture was allowed to cool to room temperature (about 21°C) followed by stirring overnight to allow complete crystallisation. The white product was filtered, washed with methanol (3 x 500 ml) and dried under vacuum at 40-45°C giving 947 g (93% yield) of coco D-gluconamide with a melting point Of 147-148°C. Analysis of monosaccharide aldonamides by gas chro atocrraphv Gas chromatography was found to be a convenient method for the examination of monosaccharide aldonamides. The method of persilylation with hexamethyldisilazane (HMDS) and trimethylchlorosilane (TMCS) in pyridine is the simplest way for producing sufficiently stable and volatile derivatives for analysis. The mixture of both agents are more reactive than either reagent alone, and the by-products combine to form neutral ammonium chloride or pyridine hydrochloride. l The purity of several monosaccharide aldonamides were determined and found to be 97-99.9%. All products were well separated from starting materials, however aldonamides with alkyl groups containing eighteen carbons or more were not volatile enough for analysis. Approximately 7-10 mg of monosaccharide aldonamide was treated with 1 ml of sil-prep reagent (pyridine: HMDS:TMS=9:3:1) in a 1 dram stoppered vial containing a magnetic stirring bar. The mixture was stirred vigorously at room temperature for 1 hour or longer prior to chromatography. The solution became cloudy owing to precipitation of NH.Cl and pyridine HC1 which was filtered through a Cameo (Trade Mark) II 25 mm filter. From 1-1.1 microlitres of the resulting mixture was injected into the gas chromatograph. All gas chromatography was conducted on a Hewlett Packard (Trade Mark) 5890 Series II Gas Chromatograph. All sample components were detected by a flame ionisation detector using a split ratio of 100:1 and separated on a crosslinked 5% phenyl ethyl silicone capillary column 25 m x 0.32 mm x 0.53 micrometres. The carrier gas was helium at 1 ml/min and the temperature program was 3 min at 140°C then 30°C/min to 250°C for 75 min. Examples 2-18 The alkyl aldonamides 2-18 in Table 1 were prepared as in Example 1. Table 1: monosaccharide alkyl aldonamide compounds without heteroatom for comparative purposes Structure (without hydrocarbon Attached Ex. radical) hydrocarbon MP(°C) % Yield % Purity HOCH Δ.C -HC -HC iHCNH- C l.__f_H ___ - K _) 101-102 93 99.9 OHOHOH D-Ribonamide OH O I II H0CH2CHCHCHCHCNH- C 7 H 15 159-160 93 99.7 I I I OHOH OH CgH 17 159-160 90 99 . 9 C g H 19 158-159 92 99 . 9 C 10 H 21 157-158 91 99 . 9 7 C 11 H 23 156-157 92 99 . 9 D-Gluconamide continued Structure (without hydrocarbon Attached EX . radical) hydrocarbon MP(°C) % Yield % Purity as Example 3 155-156 96 99.9 C 12 H 25 C 13 H 27 155-156 95 99.9 10 C 14 H 29 154-155 92 97.4 11 C 16 H 33 152-153 94 99.9 12 C 18 H 37 147-149 94 D-Gluconamide 3 OHOH 0 I I /I HOCH CHCHCHCHCNH- C 12 H 25 187-188 (d) 93 99.8 I OH OH D-Galactonamide OH OH 0 I I II 4 HOCH_CHCHCHCHCNH- C 12 H 25 187-188 (d) 95 99.7 2 I I OH OH L-Galaσtonamide OH O I if 5 HOCH CHCHCHCHCNH- C1,2_H25 c 159-160 95 99.6 z \ I I OHOH OH L-Mannonamide Structure (without hydrocarbon Attached Ex. radical) hydrocarbon MP(°C) % Yield % Purity OHOH 0 I I 'I 16 HOCH 2 CHCHCHCHCHCNH- C 12 H 25 195-197(d) 97 98.6 OH OHOH D-Glycero-L-Mannoheptonamide OH 0 I H 17 HOCH-CHCHCHCHCHCNH- C. H, ς 156-157 93 99.9 I I I I OHOH OHOH D-Glucoheptonamide OH O I II 8 HOCH,CHCHCHCHCHCHCNH- C H 156-157 93 99.9 I I I I I 2 OHOH OHOHOH D-Glucooctonamide Example 19 Preparation of octyl/decyloxypropyl D-ribonamide A 250 ml four-necked round bottom flask equipped with a condenser, additional funnel, thermometer and mechanical stirrer was charged with ribono-l,4-lactone (10 g, 0.068 mole) and methanol (37 g, for 40% solids) . The suspension was heated to 40-50°C for 15 minutes and heating mantle removed. Octyl/decyloxypropylamine (14.6 g, 0.68 mole) was added dropwise over 1/2 hour and the reaction mixture stirred for 6 hours. The white product was filtered, washed with cold acetone (3 x 10 ml) and dried under vacuum at 40-45°C giving 14 g (57% yield) of octyl/decyloxypropyl D-ribonamide with a melting point of 71-72°C and 98.7% purity (C_/C 10 : 62.8%/35.9%) . Examples 20-28 (oxygen heteroatom) The monosaccharide alkyloxypropyl aldonamides 20-28 in Table 2 were prepared as in Example 19. Table 2: monosaccharide alkyloxypropyl aldonamides Ex. Structure Hydrocarbon MP(°C) Yield Purity (%) (%) OH 0 I II 20 HOCH, CHCHCHCHCNH- C,H-0- 119-120 83 63 . 7/ I I I 35 . 6 OHOH OH C 8 H 17 /C 10 H 21 Isodecyl 2 same as 20 129-130 96 99.5 C 12 H 25 C 12 H 25 tθ C 15 H 31 4 same as 20 129-130 86 99.7 C 14 H 29 D-Gluconamide Ex. Structure Hydrocarbon MP(°C) % Yield % Purity OH O I II 25 HOCH2CHCHCHCHCHCNH- ^HgO- 129-130 88 66.2/ I I I I OHOH OHOH C 8 H 17 /C 10 H 21 33.6 isodecyl 27 same as 25 C 3 H 6 °" 133-134 89 99.9 C 12 C 25 28 same as 25 C 3 H 6 °" 128-129 75 C 12 H 25 tθ C 15 H 31 D-Gluσoheptonamide Example 29 (nitrogen heteroatom) Preparation of cocoaminopropyl D-gluconamide A 1-litre round-bottomed flask equipped with a condenser, addition funnel, thermometer and mechanical stirrer was charged with D-glucono-l,5-lactone (100 g, 0.56 mole) and methanol (208 g for 55% total solids) . The suspension was heated to 40°C over 15 minutes and the heating mantle removed. Cocoaminopropylamine (153.8 g, 0.56 mole) was added dropwise over 15 minutes with rapid stirring. The reaction mixture was cooled and placed in a refrigerator at 0°C overnight. The white product was filtered, washed with cold isopropanol (3 x 100 ml) and dried under high vacuum at 35°C giving 206 g (81% yield) of cocoaminopropyl D-glucononamide with a melting point of 109-111°C. Example 30 (nitrogen heteroatom) Soyaaminopropyl D-gluconamide was prepared as in Example 29. Example Structure Hydrocarbon MP( C) % Yield OH 0 I II 30 0HCH 2 CHCHCHCHCNH- C^gNH- 97-100 92 I I I OHOH OH soya Example 31 (nitrogen heteroatom) Preparation of oleylaminopropyl D-gluconamide A 500 ml round-bottomed flask equipped with a condenser, addition funnel, thermometer and mechanical stirrer was charged with D-glucono-l,5-lactone (25 g, 0.14 mole) and methanol (31 g, 70% total solids) . The suspension was heated to 40°C for 15 minutes and the heating mantle removed. Oleylaminopropylamine (47.72 g, 0.14 mole) was added dropwise over 10 minutes and the reaction stirred for 6 hours. Acetone (300 ml) was added and the flask placed in a refrigerator at 0°C overnight. The white product was filtered, washed with cold acetone (3 x 50 g) and dried under high vacuum at 35°C giving 65 g (89% yield) of oleylaminopropyl D-gluconamide with a melting point of 100-103°C. Examples 32-33 (oxygen and nitroσen heteroatoms) Example Structure Hydrocarbon MP( U C) Yield OH 0 32 HOCH CHCHCHCHCNH- C 3 H 6 NHC 3 H 6 0- 70-77 84 I I I OHOH OH isotridecyl 33 same as 32 C 3 H 6 NHC 3 H 6 0- 91-95 87 C 12 H 25 tθ C 15 H 31 D-Gluconamide In each of Examples 20-33, it should be appreciated, to the extent it is not clear, that the hydrocarbon radical is all one radical with the portion of the radical on any line attached to the portion immediately above it. For example, in Example 21, the radical is C 3 H g O-isodecyl. Also, a slash represents a mixture of radicals. Thus, Example 20 represents a mixture of and radicals. Example 34 Preparation of N-dodecyl lactobionamide (used for comparative purposes) 30 g of lactobiono-l,5-lactone (1 eq) was dissolved in 70 ml of anhydrous dimethylformamide (DMF) at 75-80°C. 15.85 g (1 eq) dodecylamine was added, the reaction mixture was kept stirring at 70-80°C for 30 minutes. The reaction was allowed to cool, diethyl ether (200 ml) was added. The product was filtered and washed with diethyl ether (2 x 150 ml) and recrystallisation from methanol gave 90% of the desired product. Example 35 Preparation of N-tetradecyl lactobionamide (used for comparative purposes) Lactobiono-l,5-lactone (20 g, 1 eq) was dissolved in 60 ml of anhydrous DMF at 65°C. 12.5 g of tetradecylamine (1 eq) was added, the reaction was stirred at 65°C for 30 minutes. The reaction mixture was cooled, diethyl ether (2 x 150 ml) was added. The product was filtered and washed with diethyl ether. Recrystallisation from methanol yielded 92% of the desired product. Example 36 Preparation of N-hexadecyl lactobionamide (used for comparative purposes) The same procedure was employed as in Example 35 using 10 g of lactobiono-l,5-lactone (1 eq) and 7.1 g of hexadecylamine (1 eq) . Recrystallisation from methanol yielded 90% of the desired product. Example 37 Preparation of lactobionyl dodecyl glvcinate 9.0 g of dodecyl glycinate hydrochloride was dissolved in 50 ml of anhydrous methanol by gentle heating, 16 ml of 2.0 M methanolic ammonia was added, followed by addition of 10.9 g (1 eq) of lactobiono-l,5-lactone. The reaction mixture was heated to reflux for 1 hour, activated charcoal was added and the mixture was filtered hot. The solvent was removed, the product was washed with diethyl ether and dried in a vacuum oven at 40°C with P^O j . to give a yield of approximately 75%. Example 38 Preparation of lactobionyl dodecyl beta-alanate The same procedure was employed as described above for lactobionyl dodecyl glycinate except 3.0 g of dodecyl b-alanate hydrochloride and 3.45 g of lactobiono-l,5-lactone in anhydrous methanol were used. The yield was approximately 70%. Example 39 Preparation of dodecyloxypropyl lactobionamide Lactobiono-l,5-lactone (180 g, 1 eq) was dissolved in methanol (50°C, 1.1 litre) dodecyloxypropylamine (115.8, 1 eq) was added slowly. After the addition was complete, the reaction was stirred overnight at room temperature. The product was filtered, washed twice with warm acetone and dried in a vacuum oven at 40°C. The yield was 215 g (72.7%). Example 40 Preparation of tetradecyloxypropyl lactobionamide Lactobiono-l,5-lactone (500 g, 1 eq) was dissolved in methanol (50°C, 3 litres) tetradecyloxypropylamine (Adogen 184 {R}, 385 g, 1 eq) was added in several portion slowly. After the addition have completed, the reaction was stirred at room temperature overnight. The product was filtered, washed twice with warm acetone, and dried in a vacuum oven at 40°C. The yield was 647 g (73.1%). Example 41: Krafft Points The temperature at and above which surfactants begin to form micelles instead of precipitates is referred to as Krafft Point (T.) and at this temperature the solubility of a surfactant becomes equal to its critical micelle concentration or CMC (numerical value at which micelles are formed) . The appearance and development of micelles are important since detergency and solubilisation of surfactants in dishwashing liquids, shampoos, detergents, etc depend on the formation of these aggregates in solution. The Krafft point was measured by preparing 650 ml of a 0.1% or 1.0% by weight dispersion of aldonamide in water. If the surfactant was soluble at room temperature, the solution was slowly cooled to 0°C. If the surfactant did not precipitate out of solution, its Krafft point was considered to be <0°C. If it precipitated out of solution, the temperature at which precipitation occurred was taken as the Krafft point. If the surfactant was insoluble at room temperature, the dispersion was slowly heated until the solution became homogeneous. It was then slowly cooled until precipitation occurred. The temperature at which the surfactant precipitated out of solution was taken as the Krafft point. The results are set out below under Examples 43-46. Example 42: Foam Height Foam is an important attribute in many consumer products. It is one of the dominant factors that determines the commercial value of products such as shampoo, soap, etc. Also, acceptability of many consumer products is closely related to the quality and texture of the foam they produce (psychological aspect) . Since most foaming data on surfactants is typically obtained by the Ross-Miles method (Ross J and Miles G D, Am Soc for Testing Material Method D1173-53, Philadelphia, PA. (1953) ; Oil & Soap (1958) .62 : 1260) the foaming ability of these surfactants was also assessed using this method. In the Ross-Miles method, 200 ml of a solution of surfactant contained in a pipette of specified dimensions with a 2.9 mm internal diameter orifice is allowed to fall 90 cm onto 50 ml of the same solution contained in a cylindrical vessel maintained at a given temperature (often 60°C) by means of a water jacket. The height of the foam produced in the cylindrical vessel is read immediately after all the solution has run out of the pipette (initial foam height) and then again after a given amount of time (generally, 5 minutes) . Using this method, the foam production (initial foam height in mm) and foam stability (final foam height after 10 minutes in mm) were measured at 0.1% aldonamide concentration 40°C and 0 ppm (parts per million) hardness. Aldonamides that were not soluble at 40°C were measured 5-10°C above their Krafft point. In order to show the unexpected enhancement in solubility and foam stabilisation of the compounds of the invention relative to similar aldonamide compounds having no heteroatom in the attached aliphatic group, applicants compared a series of alkyl aldonamides and aldobionamides lacking a heteroatom in the hydrocarbon radical to those containing a heteroatom in the hydrocarbon radical. The results are set out below under Examples 43-46. Example 43 Monosaccharide aldonamides containing four hydroxyl groups Entry Compound Hydrocarbon Foam height (mm) Krafft chain length point (average) initial final (°C) C 12 ribonamide 12 184 103 54 (comparative) B C 8 /C 10 oχ YP ro P vl ιi-5 217 200 10 D-ribonamide This example clearly shows that when a heteroatom is added, foaming is enhanced and solubility increased. Example 44 Monosaccharide aldonamides containing five hydroxyl groups Entry Compound Hydrocarbon Foam height (mm) Krafft chain length point (average) initial final (°C) Entries C to N (Comparative) C 7 D-Gluconamide <0 C g D-Gluconamide 12 C g D-Gluconamide 53 C D-Gluconamide 10 199 75 C..- D-Gluconamide 11 X X 87 H 12 D ~ G uconam i^ e I 2 X 91 C 12 D-Galactonamide 12 - Insoluble - >100 C 12 L-Galactonamide 12 - Insoluble - >100 K C. L-Mannonamide 12 - Insoluble - >100 C1.4. D-Glucona ide 14 - Insoluble - >100 M C 1-6_ D-Gluconamide 16 - Insoluble - >100 N C ιg D-Gluconamide 18 - Insoluble - >100 Entry Compound Hydrocarbon Foam height (mm) Krafft chain length point (average) initial final ( C) Entries 0 to W (Invention) o c 8 /c ιo 0χ yp r °py 1 ll ' 5 212 i65 48 ISO C 10 13 213 206 <0 Oxypropyl D-Gluconamide Q C 12 Oxypropyl 15 200 110 61 D-Gluconamide R 12 ~ C 15 0χ yP ro Py 16.25 200 105 58 D-Gluconamide S C 14 Oxypropyl 17 203 101 53 D-Gluconamide T Cocoaminopropyl 16 186 182 18 D-Gluconamide U Oleylaminopropyl 21 158 84 <18 D-Gluconamide V ISO C 13 19 180 178 <0 Oxypropylamino propyl D-Gluconamide W C 10 -C. c 19.25 180 176 <0 Oxypropylamino propyl D-Gluconamide X in the Table indicates that the foam height of these high Krafft point materials could not be measured. Entries C-N are comparative and 0-W are compounds of the invention. The best comparisons are based on average number of hydrocarbons. From the above table, it can be seen that compounds without heteroatoms become increasingly insoluble in water resulting in poor or no foaming. By contrast, when a heteroatom is present, enhanced foaming and reduced Krafft point can be seen in all cases, even entry U which contains 21 carbon atoms. Also, it can be seen that when more than one heteroatom is present (entries V and W) , Krafft points are significantly lower (ie less than 0) indicating enhanced solubility for compounds that have a longer than average hydrocarbon chain length which otherwise would be normally insoluble. Example 45 Monosaccharide aldonamides containing six hydroxyl groups This example shows that merely increasing hydrophilicity of the sugar (by hydroxyl group addition) does not enhance solubility (comparative entries X, Y & Z) . However, when a heteroatom is introduced into the hydrocarbon radical Krafft points are reduced and foaming enhanced (entries AA-DD) . Example 45 Monosaccharide aldonamides containing six hydroxyl groups Entry Compound Hydrocarbon Foam height (mm) Krafft chain length point (average) initial final (°C) Entries X to Z (comparative) X C 12 D-Glycero-L- 12 - Insoluble >100 Mannoheptonamide "12 12 X X 91 D-Glucoheptonamide "12 12 X 86 D-Glucooctonamide Entries AA to DD (invention) AA C R / IO 0χ yp r °pyi ιι.5 221 90 60 D-Glucoheptonamide BB Iso C_ 0 Oxypropyl 13 215 204 18 D-Glucoheptonamide CC C 12 Oxypropyl 15 245 80 73 D-Glucoheptonamide DD C 12 ~C 15 Oxypropyl 16.25 239 97 68 D-Glucoheptonamide Example 46 Disaccharide aldobionamides containing eight hvdroxyl groups Entry Compound Hydrocarbon Foam height (mm) Krafft chain length point (average) initial final ( C) Entries EE to GG (comparative) EE "12 12 153 20 38 Lactobionamide FF "14 14 145 140 46 D-Lactobionamide GG "16 16 95 95 48 D-Lactobionamide Entries HH to KK (invention) HH D-Lactobionyl 14 161 153 <0 C- 2 Glycinate II D-Lactobionyl 15 159 152 <0 C 12 beta-alanate JJ '12 Oxypropyl 15 165 154 <0 D-Lactobionamide KK C- 4 Oxypropyl 17 163 154 <0 D-Lactobionamide This example shows that use of the heteroatom in aldobionamides clearly enhances foaming and greatly reduces Krafft point, ie from 38°C, 46°C and 48°C in comparative entries EE-GG to below 0°C in all compounds of the invention. Discussion of Examples 43-46 The data clearly show that alkyl gluconamides lacking a heteroatom in the hydrocarbon chain (E-H, L-N) are inferior foa ers and have higher Krafft points. While not wishing to be bound by theory, it is believed that these compounds pack closely in the solid state through strong amide/hydroxyl hydrogen bonding and hydrocarbon Van der Waal forces. The net results is an unfavourable heat of hydration, high Krafft point, low or no water solubility and poor foaming profile. Changing the stereochemistry (I-K) or increasing the hydrophilicity (X-Z) of the sugar head group (by hydroxyl group addition) results in little improvement. However, monosaccharide alkyl aldonamides that contain a heteroatom such as oxygen (B,0-S, AA-DD) or nitrogen (T, U) on both (V, W) in the hydrocarbon chain are believed to pack more favourably in the solid state thereby resulting in a low Krafft point, increased water solubility and superior foaming profile. Also, closer comparison reveals that monosaccharide aldonamides containing a heteroatom in the hydrocarbon chain unexpectedly allow the introduction of the same or greater alkyl chain length without sacrificing foaming and solubility characteristics. (Compare the average number of hydrocarbons of L-N to Q-W and Y to AA-DD) . Disaccharide alkyl lactobionamides (EE-GG) tend to have reasonable Krafft points and foaming profiles. However, the addition of a heteroatom such as oxygen in the form of an ester (HH, II) or ether (JJ, KK) in the hydrocarbon chain results in a extremely low Krafft points (<0°C) , increased water solubility and enhanced foaming.

Claims: CLAIMS 1 Use of a saccharide aldonamide compound of the general formula I: wherein S represents a mono-, di- or oligosaccharide unit, A or X represents H or a C^C . alkyl group, Y represents a group or atom selected from O O 0 0 II H II II -0-, -S-, -NH-, -C-0-, -0-C-, -NH-C-, -C-NH-, „R represents a straight or branched C_ or above hydrocarbon radical optionally containing a substituted or unsubstituted aromatic or cycloaliphatic radical, m is an integer from 1 to 4, p is 0 or an integer from 1 to 10, as a surfactant or foaming agent in a surface-active and/or foaming composition. 2 Use of a compound as claimed in claim 1, wherein S represents a monosaccharide unit of the formula: wherein n represents an integer of from 1 to 6, Use of a compound as claimed in claim 2, wherein n is 4 4 Use of a compound as claimed in claim 2, wherein Y represents O, S or NH. 5 Use of a compound as claimed in claim 1, wherein S represents a di- or oligosaccharide unit of the formula: HO-CH--CH—CH—CH—CH— I I I I OH OG OH OH wherein G represents a mono-, di- or oligosaccharide unit. 6 Use of a compound as claimed in any preceding claim wherein X represents a hydrogen atom. 7 Use of a compound as claimed in any preceding claim wherein m is 3. 8 Use of a compound as claimed in any preceding claim wherein Y represents an oxygen atom. 9 Use of a compound as claimed in any preceding claim wherein p is zero. 10 Use of a compound as claimed in any preceding claim wherein A represents a hydrogen atom. 11 Use of a compound as claimed in any preceding claim wherein R represents a C. to C 24 alkyl group. 12 Use of a compound as claimed in claim 11 wherein R represents a C 1Q to C 14 alkyl group. 13 Use of a compound as claimed in claim 1 which is a Co 0 to C- oxypropyl D-gluconamide. 14 Use of a compound in claimed in claim 1 which is a C 1.6, to C 21 aminopropyl D-gluconamide. 15 Use of a compound as claimed in claim 1 which is C._ or C- oxypropyl lactobionamide. 16 Use of a compound as claimed in claim 1 which is D-lactobionyl C-.-beta alanate or D-lactobionyl C- 2 glycinate. 17 A detergent composition comprising a detersive and/or foaming amount of a compound of the formula I as defined in claim 1. 18 A monosaccharide aldonamide compound of the formula la, wherein S. represents a monosaccharide unit of the formula wherein n represents an integer of from 1 to 6, represents H, a C.-C 0 hydrocarbon radical, or X represents H or a C 1 -C 4 alkyl group, Y., represents -0-, -S- or -NH-, R represents a straight or branched C_ or above hydrocarbon radical optionally containing a substituted or unsubstituted aromatic or cycloaliphatic radical, m is an integer from 1 to 4, p is 0 or an integer from 1 to 10. 19 A di- or oligosaccharide aldonamide compound of the formula lb, S 2 wherein S, represents a di- or oligosaccharide unit of the formula HO-CH--CH—CH—CH—CH— OH OG OH OH wherein G represents a mono-, di- or oligosaccharide unit, A or X represents H or a C.,-C 4 alkyl group, Y represents a group or atom selected from 0 0 0 0 II II II II -0-, -S-, -NH-, -C-O- -0-C-, -NH-C-, -C-NH-, R represents a straight or branched C_ or above hydrocarbon radical optionally containing a substituted or unsubstituted aromatic or cycloaliphatic radical, m is an integer from 1 to 4, p is 0 or an integer from 1 to 10.

Inventors: AU VAN, HARIRCHAIN BIJAN, VERMEER ROBERT, AU, VAN, HARIRCHAIN, BIJAN, VERMEER, ROBERT
Applicants: UNILEVER NV, UNILEVER PLC
Application year: 1993
Main classification: C07H15
IPC codes: A61K8, A61Q5, A61Q19, C07C235, C07H15, C11D1