text: suitable examples of n - alkyl - n -( desoxyhexityl ) acetic acid salts having formula ( iv ) ## str8 ## include those in which n is 4 - 24 , preferably 8 - 14 , and r preferably is a desoxyhexityl group such as , for example , 1 - desoxy - 1 - glucityl -, 2 - desoxy - 2 - glucityl -, 3 - desoxy - 3 - glucityl -, 1 - desoxy - 1 - mannityl , 2 - desoxy - 2 - mannityl -, 3 - desoxy - 3 - mannityl -, 1 - desoxy - 1 - dulcityl -, 2 - desoxy - 2 - dulcityl -, 3 - desoxy - 3 - dulcityl -, 1 - desoxy - 1 - allityl -, 2 - desoxy - 2 - allityl -, 3 - desoxy - 3 - allityl -, 1 - desoxy - 1 - altrityl -, 2 - desoxy - 2 - altrityl -, 3 - desoxy - 3 - altrityl -, 1 - desoxy - 1 - talityl -, 2 - desoxy - 2 - talityl - or 3 - desoxy - 3 - talityl -. preferably , r is a 1 - desoxy - 1 - glucityl group , and x is na . it has not been found surprisingly that the trisubstituted amphoteric compounds of formula iv of the present invention have outstanding surfactant properties . in comparison with trisuibstituted amphoteric surfactants of formula iii , they have good water solubility . the trisubstituted amphoteric surfactants of the present invention also show good skin tolerability . the c 12 - alkylglucamino acetate in particular shows exceptional properties which include no opalescence over the entire ph range from 2 to 12 and good solubility such that clear solutions are formed . chemical compounds of formula iv are prepared by carboxymethylation of n - alkylglycamines , for example , n - alkyl - 1 - amino - 1 - desoxyhexitols , by generally known procedures depending on the solubility of the amine in water or butanol as solvent . by maintaining a ph of 8 - 9 by continuous addition of alkali such as an alkali metal hydroxide of which sodium hydroxide is preferred , and maintaining a reaction temperature below 80 ° c ., selective n - carboxymethylation is achieved without the oh groups of the hexityl structure reacting . the n - alkylglycamines themselves are prepared by generally familiar procedures of reductive amination of monosaccharides ( u . s . pat . nos . 1 , 994 , 467 ; 2 , 016 , 962 ), particularly hexoses with alkylamines such as butylamine , octylamine , laurylamine , myristylamine , stearylamine , or coco fatty amine , with the following being mentioned as examples of monosaccharides : glucose , galactose , mannose , fructose , allose , altrose , talose , and glucose syrup . the n - alkylglycamino compound of the present invention is normally incorporated in a detergent formulation in an amount ranging from 2 to 50 % by wt , preferably 10 - 30 % by wt . the n - alkylglycamino compound of the invention can be combined with other surfactants including ether carboxylates , nonionic surfactants , amine oxide compounds , paraffin sulfonate compounds , sulfosuccinic acid semi - esters and the like . the detergent formulations include other additives such as thickeners , fatty acid diethanol amides and preservatives . the present n - alkylglycamino compound is particularly useful in the preparation of formulations used in the body and hair , such as in bubble bath and hair shampoos where mild detergent formulations are needed . having now generally described this invention , a further understanding can be obtained by reference to certain specific examples which are provided herein for purposes of illustration only and are not intended to be limiting unless otherwise specified . a 19 . 4 g ( 0 . 205 mole ) amount of chloroacetic acid is dissolved in 106 . 2 g ( 5 . 9 moles ) of water and 58 . 6 g ( 0 . 2 mole ) of octylglucamine is added in portions with stirring . at the same time the temperature is raised to 60 ° c .. after the octylglucamine has dissolved completely , 102 . 4 g ( 88 ml , 0 . 409 mole ) of a 16 % sodium hydroxide solution is added dropwise at a ph between 8 and 9 . toward the end of the reaction the temperature is raised to 65 ° c .. after the sodium hydroxide has been completely added , the mixture is allowed to react for 1 hour at 70 ° c . the unreacted octylglucamine precipitates in the cold ( 6 . 5 g , m . p . : 121 °- 123 ° c ., alkali number : 183 . 6 mg koh / g ), and is removed by filtration . the filtrate is then evaporated to dryness . ______________________________________yield : 78 . 6 g ( 83 . 2 %) melting range : 80 - 154 ° c . nitrogen content : 3 . 01 % ( 3 . 75 %) carboxyl number : 121 mg koh / gpurity : 79 % octylglucamino - acetic acid na - salt (. sup . 13 c nmr ) 6 % na glycolate 15 % nacl______________________________________ a 19 . 4 ( 0 . 205 mole ) amount of chloroacetic acid is dissolved in 192 . 6 g ( 2 . 6 moles ) of n - butanol and 64 . 2 g ( 0 . 2 mole ) of decylglucamine is added in portions with stirring . the temperature is raised to 60 ° c . after the decylglucamine has completely dissolved , 102 . 4 g ( 88 ml , 0 . 409 mole ) of a 15 % sodium hydroxide solution is added dropwise at a ph between 8 and 9 . toward the end of the reaction the temperature is raised to 65 ° c .. after completing the addition of sodium hydroxide solution , the mixture is allowed to react for 1 hour at 70 ° c .. the water is then removed by distillation azeotropically with continuous addition of n - butanol . nacl precipitates , and is filtered while the solution is hot . a white precipitate separates from the filtrate in the cold . the separated precipitate is dissolved in hot water in a 1 : 3 ratio and is then cooled . the unreacted decylglucamine precipitates ( 2 . 5 g , m . p . : 122 °- 123 ° c ., alkali number : 170 mg koh / g ) and is removed by filtration . the filtrate is evaporated to dryness . ______________________________________yield : 67 . 4 g ( 84 %) melting range : 95 - 171 ° c . nitrogen content : 3 . 25 % carboxyl number : 132 . 0 mg koh / gpurity : 92 . 7 % decylglucamino - acetic acid na - salt (. sup . 13 c nmr ) 2 . 6 % decylglucamine 4 . 2 % na glycolate 0 . 51 nacl______________________________________ chloroacetic acid is reacted with dodecylglucamine by the same method described in example 2 . ______________________________________yield : 71 . 5 g ( 83 . 3 %) melting point : 172 - 174 ° c . nitrogen content : 3 . 07 % carboxyl number : 115 . 3 mg koh / gpurity : 96 . 0 % dodecylgluca - minoacetic acid na - salt (. sup . 13 c nmr ) 2 . 4 % na qlycolate 1 . 6 % nacl______________________________________ chloroacetic acid is reacted with tetradecylglucamine by the same method described in example 2 . ______________________________________yield : 94 . 9 g ( 97 . 8 %) melting range : 160 - 162 ° c . nitrogen content : 2 . 88 % carboxyl number : 111 . 6 mg koh / gpurity : 97 . 8 & amp ; tetradecylgluca - minoacetic acid na - salt (. sup . 13 c nmr ) 1 . 8 % na glycolate 0 . 4 % nacl______________________________________ chloroacetic acid is converted with hexadecylglucamine by the same method described in example 2 . ______________________________________yield : 95 g ( 97 . 8 %) melting range : 90 - 162 ° c . nitrogen content : 2 . 83 % purity : 85 . 3 % hexadecylgluca - minoacetic acid na - salt (. sup . 13 c nmr ) 12 . 0 % hexadecylglu - camine 2 . 3 % na glycolate 0 . 35 % nacl______________________________________ chloroacetic acid is reacted with octadecylglucamine by the same method described in example 2 . ______________________________________yield : 91 . 8 g ( 89 . 5 %) melting range : 75 - 132 ° c ., 210 ° c . dec . nitrogen conetne : 3 . 72 % purity : 83 . 6 % octadecylgluca - minoacetic acid na - salt (. sup . 13 c nmr ) 12 . 8 % octadecylglu - camine 3 . 3 % na glycolate 0 . 30 % nacl______________________________________ the alkylglucaminoacetates in which n = 8 , 10 , 12 , 14 , 16 , and 18 , synthesized as described above were measured as 1 % aqueous solutions after adjusting the ph to 5 . 6 . fig1 shows the results of the measurement of interfacial tension and of surface tension ( bottom of the illustration ) and of the critical micelle concentration with a lauda tensiometer ( top of the illustration ), measured against air or paraffin by the du nouy ring method . in their surface - active properties , the glucaminoacetates show conventional behavior with respect to the lowering of surface and interfacial tension . for comparison , the surface and interfacial tension and the critical micelle concentration of carboxymethyldimethylcoco - ammonium betaine ( r - n + ( ch 3 ) 2 -- ch 2 coo - in which r = c 12 - c 14 ), a commercial betaine , were determined ( see table 1 ). table 1______________________________________surface / interfacial tension and critical micelleconcentration ( cmc ) interfacial surface tension ( 20 ° c ., tension ( 20 ° c . ; versus in cd water ) paraffin ) cmc st cmc it ( g / l ) ( mn / m ) ( g / l ) ( mn / m ) ______________________________________dodecylglucamino - 0 . 37 33 . 0 0 . 22 5 . 8acetic acidtetradecylglu - 0 . 058 32 . 8 0 . 03 5 . 8minoacetic acidbetaine 0 . 04 33 . 2 0 . 61 3 . 2______________________________________ cd = completely deionized water the foaming power of the alkylglucaminoacetates of example 7 were measured according to din 53 902 as 0 . 1 % aqueous solutions with ph adjustments of 9 . 9 ± 0 . 3 ; 7 . 00 , and 5 . 60 . at ph 7 . 00 and 5 . 60 the c 16 and c 18 glucaminoacetic acids show inadequate solubility . the results are shown in fig2 a ( for ph 9 . 9 ± 0 . 3 ), 2b ( for ph 7 . 00 ), and 2c ( for ph 5 . 6 ). each of the solid lines means the values after 30 seconds and the broken curve means the values after 300 seconds . the maximum foaming power was reached with the dodecylgluicaminoacetate . the values produced ( readings after 30 s / 300 s ) of 580 ml / 560 ml are comparable with those of the commercial anionic surfactant ( marlon ® a : alkylbenzenesulfonate ) of 590 ml / 570 ml , and are distinctly higher than those of the ether sulfate ( marlinat ® 242 : c 12 - 14 with 2 . 2 eo ) with 540 ml / 540 ml and of carboxymethyldimethylcocoammonium betaine with 510 ml / 500 ml . in spite of the ampholytic nature of the alkylglucamino compounds , no ph dependency can be observed . by mixing the alkylglucamino compounds with the surfactant marlinat ® 242 the foaming power of the short - chained alkylglucamino - acetic acids can be increased distinctly . the maximum is likewise reached with dodecylglucaminoacetate ( see fig3 : measured at ph 5 . 60 , solid line shows values after 30 seconds , broken line values after 300 seconds ). the use of a surfactant in shampoos assumes good wetting of the hair . to evaluate the wetting , the wetting angle between a partly immersed hair and the surface of the surfactant solution was used [ colloids and surfaces 6 ( 1983 ) 49 - 61 ]. dodecylglucaminoacetic acid na salt as a 0 . 1 % surfactant solution at ph 6 , based on water , shows a wetting angle reduction of 53 . 8 %. skin tolerability was determined by the gotte zein test ( cid brussels 1984 , 83 - 90 ). fig4 shows the results for the alkylglucamino - acetic acid na salts of examples 1 to 4 in 1 % aqueous solution at ph 5 . 6 . the zein numbers found indicate very good skin tolerability . they are clearly below the value of the commercial anionic surfactant marlon ® a of 510 mg n / 100 ml and are comparable with those of the betaines , with which zein numbers of about 50 mg n / 100 ml are achieved . the table below provides a comparison between a formulation within the scope of the present invention ( no . 2 ) and a conventional formulation ( no . 1 ) which does not contain the n - alkylglycamino compound of the invention . ______________________________________application example : components shampoo 1 shampoo 2______________________________________marlinat 242 ( w = 0 . 28 ) 13 . 9 13 . 9ampholyte jp 130 ( w = 0 . 30 ) 17 . 8 -- glucamine - na - salt ( w = 0 . 4 ) -- 11 . 4bervoxyl vlb 1132 ( w = 0 . 4 ) 11 . 4 11 . 4dionil oc 2 . 0 2 . 0lamepon s 2 . 0 2 . 0remainderconventional additives 0 . 62 2 . 62water ad 100 ad 100propertiesfoam capacity at 20 ° c . [ ml ] after [ ml ] after / illegible / cd water 540 / 525 540 / 555drinking water 425 / 405 480 / 460viscosity at 20 ° c . [ mpas ] 2605 3002______________________________________ marlinat 242 = 28 % coconut butter alcohol 2 eo sulfate nasalt ampholyte jp 130 = 30 % coconut butter acid amidopropylbetaine glucaminena - salt = ndodecyl - n - carboxymethyl - glucamine - na - salt servoxyl vlb 1123 = 40 % lauryl 3 eo sulfosuccinatena dionil oc = oleic acid monoethanolamide = 3 eo lamepon ® s = protein fatty acid condensate having now fully described the invention , it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the invention as set forth herein .