Alkyl esters of n-carboalkyloxy amino-11-undecanoic acids, their processes of preparation and their use as thickening agents

Abstract

The alkyl esters of N-carboalkyloxy-11-aminoundecanoic acids have the following general formula: ##STR1## wherein R is linear or branched C.sub.7-30 alkyl, linear or branched C.sub.4-22 alkenyl or a radical of formula: ##STR2## wherein n is 0 to 5 R" is linear or branched C.sub.7-30 alkyl, andR' is linear C.sub.10-18 alkyl.These esters, and esters wherein R is additionally hydrogen or C.sub.1-6, have an application as thickening agents in organic media particularly in the cosmetic field.

Description

BACKGROUND OF THE INVENTION

(i) Field of the Invention

This invention relates to new alkyl esters of N-carboalkyloxy amino-11-undecanoic acids and to their processes of preparation and their use as thickening agents particularly in organic media. The new compounds have applications particularly in the thickening and/or solidification of oily liquids and organic solvents such as may be used for example in cosmetics, pharmacy, paints and varnishes, lubricants, fuels as well as in the food industry. These compounds have proved by their properties to be the thickeners of choice for a large number of cosmetic compositions particularly nail varnish.

(ii) Description of the Prior Art

Current thickeners for non-aqueous milieux include N-acylaminoacids, salts of fatty acids, e.g. aluminium, magnesium or calcium salts, glycerol esters of fatty acids, inorganic colloids such as bentone, as well as natural products like beeswax or even carnauba wax.

OBJECTS OF THE INVENTION

It is an object of the present invention to provide thickening agents of non-ionic character or very slightly ionic in character. It is a further object of this invention to provide thickeners able to mix with a variety of other adjuvants such as, for example, surfactants, polymers, preservatives, colourants, pigments, perfumes and a variety of active compounds.

SUMMARY OF THE INVENTION

The invention provides alkyl esters of N-carboalkyloxy amino-11-undecanoic acids of general formula: ##STR3## in which: R is linear or branched C.sub.7-30 alkyl, linear or branched C.sub.4-22 alkenyl or a radical of formula: ##STR4## in which: n is 0 to 5

R" is H, linear or branched C.sub.1-9 alkyl, and R' is linear C.sub.10-18 alkyl.

DESCRIPTION OF PREFERRED EMBODIMENTS

When R is linear or branched C.sub.7-30 alkyl, it is preferably octyl, dodecyl, tetradecyl, hexadecyl, octadecyl, hexyl-2-decyl, isostearyl, docosyl or triacontyl.

When R is linear or branched C.sub.4-22 alkenyl, it is preferably undecen-10-yl,octadecen-9-yl (=oleyl) or docosen-13-yl (erucyl). ##STR5## it is preferably benzyl, phenethyl, p-xylyl or nonylphenyl.

R' is preferably dodecyl, tetradecyl, hexadecyl or octadecyl but in particular, hexadecyl.

According to one embodiment of the invention, R is linear or branched C.sub.14-20 alkyl.

It has been discovered in a wholly surprising and unexpected manner that these alkyl esters of N-carboalkyloxy amino-11-undecanoic acids possess excellent thixotropic properties which are particularly interesting and sought after for varnishes, especially nail varnish.

Among the compounds covered by general formula I above the following are worth mentioning:

______________________________________octyl N-carbohexadecyloxy amino-11-undecanoate,dodecyl N-carbohexadecyloxy amino-11-undecanoate,tetradecyl N-carbohexadecyloxy amino-11-undecanoate,hexadecyl N-carbohexadecyloxy amino-11-undecanoate,octadecyl N-carbohexadecyloxy amino-11-undecanoate,docosyl N-carbohexadecyloxy amino-11-undecanoate,triacontyl N-carbohexadecyloxy amino-11-undecanoate,oleyl N-carbohexadecyloxy amino-11-undecanoate,isostearyl N-carbohexadecyloxy amino-11-undecanoate,benzyl N-carbohexadecyloxy amino-11-undecanoate, andhexadecyl N-carbodecyloxy amino-11-undecanoate.______________________________________

The present invention also relates to the process for preparing the above defined N-carboalkyloxy amino-11-undecanoic acid esters.

Various methods may be employed for the synthesis of these compounds. One such comprises reacting a fatty alcohol (R'--OH) with an isocyanate of formula: O.dbd.C.dbd.N--(CH.sub.2).sub.10 --CO--OR (II), R and R' being as defined above for formula I.

Another method comprises reacting a chloroformiate of formula R'OCOCl or an azolide of formula: ##STR6## with an amine of formula H.sub.2 N--(CH.sub.2).sub.10 --CO--OR (III),

R and R' being as defined above.

These two methods, which aim to produce the carbamate function, may be carried out according to conventional methods, such as are described in particular in "Advanced Organic Chemistry" Third Edition, Ed. Jerry, March 1985, incorporated herein by reference. The reactions are generally conducted in organic and/or aqueous solvent(s) in the presence of a base which is preferably caustic soda, caustic potash or triethylamine.

These methods may also be carried out starting from the acids of compounds II and III (i.e. where R=H) in which case the esters are obtained by classical methods notably by esterification in the presence of the chosen alcohol (optionally in excess) and of an acidic catalyst such as sulphuric acid or paratoluene sulphonic acid optionally in an organic solvent, preferably an aromatic solvent such as toluene.

Again starting from the salts of these acids, it is possible to produce the esters by classical methods, notably by substitution using halide compounds or alkoyl sulphonates, in organic solvent(s) or by phase transfer.

It is also possible to obtain the claimed esters by transesterification starting from methyl and ethyl esters and the desired alcohol.

The present invention also relates to the use of the compounds of formula I according to the invention, wherein R may additionally be H or C.sub.1 to C.sub.6, as thickening agents of certain solvents, oils, paints and varnishes, cosmetic compositions, particularly nail varnish, and pharmaceutical compositions.

Representative animal, vegetable or mineral oils which may be thickened using the compounds of the invention include vaseline, colza oil, olive oil, jojoba oil, perhydrosqualene as well as silicone oils and esters of fatty acids.

Representative solvents include hydrocarbons such as xylene, toluene, heptane, isooctane, esters such as butyl acetate, isopropyl myristate, ketones such as methylisobutylketone, acetone, chlorinated hydrocarbons such as 1,2-dichloroethane, glycol ethers such as polyethylene glycol, 2-butoxyethanol, alcohols such as ethanol, isopropanol, 2-ethylhexanol, polyoxyethenated alkoylphenols etc.

The thickening of these media is effected by dissolution therein of all the thickening agent and thereafter puting the mixture aside until it has completely thickened. It is possible to achieve a homogenous mixture at temperatures between ambient and the boiling point of the organic liquid followed by cooling the solution thus obtained.

The proportion of thickening agent according to the invention may vary within a broad range depending on the medium to be thickened but lies generally between 0.1 and 25% by weight referred to the total weight of the medium.

In the case of cosmetic and pharmaceutical compositions, the porportion of thickening agents lies generally between 0.1 and 15% by weight referred to the total weight of the composition.

Here, various formulations are possible such as for example water-in-oil emulsions, oil-in-water emulsions, sticks, milks, etc. The compounds of formula I according to the invention where R is linear or branched C.sub.14-20 alkyl have application as thixotropic thickeners in nail varnish. In this particular embodiment, they are generally present in a proportion between 0.2 and 7% by weight related to the total weight of the nail varnish.

There now follows for the purposes of illustration and without any intent to limit the scope of the present invention, several examples of preparing N-carboalkyloxy amino-11-undecanoic acid esters as well as several examples of the use of these compounds as thickening agents.

EXAMPLE A

Preparation of N-carbohexadecyloxy-11-aminoundecanoic acid

40.2 g of 11-amino-undecanoic acid (0.2 mol) are dissolved in a mixture of 450 ml acetone and 200 ml of 1N caustic soda.

Simultaneously 60.9 g (0.2 mol) of hexadecyl chloroformate are added along with 200 ml of a 1N caustic soda solution.

A white precipitate progressively appears in the reaction medium which is continuously agitated for 5 hours. Thereafter, the reaction medium is filtered and the white precipitate obtained is washed with water. The alkaline salt obtained is filtered under vacuum then dissolved and acidified in 650 ml of hot acetic acid. Reducing to ambient temperature leads to the appearance of a white precipitate which is filtered and washed with acetone.

The acid thus obtained is dried under vacuum at 40.degree. C. to constant weight of no less than 79 g (minimum yield: 85%) having a melting point of 100.degree. C..+-.1.degree. C.

The 13-C NMR spectrum corresponds to the expected structure.

IR spectrum: 1538 cm-1 and 1679 cm-1 (carbamate).

______________________________________Quantitative analysis of C.sub.28 H.sub.55 NO.sub.4 C % H % N % O %______________________________________Calculated 71.59 11.80 2.98 13.62Found 71.40 11.84 2.93 13.68______________________________________

EXAMPLE B

Preparation of N-carbodecyloxy-11-aminoundecanoic acid

Using the same procedure as in example A, and using 44.1 g of decyl chloroformiate, 61 g of white crystals are obtained (yield=80%) having a melting point of 91.degree. C.

The 1-H NMR spectrum accords with the expected structure.

IR spectrum: 1679 cm-1 and 1535 cm-1 (carbamate)

EXAMPLE 1

Preparation of octyl N-carbohexadecyloxy-11-aminoundecanoate

1.5 g octanol, 300 mg paratoluene sulphonic acid and 120 ml toluene are added to 5 g of the acid obtained in example A. Dehydration is carried out by azeotropic entrainment for 16 hours after which the reaction medium is evaporated to dryness under vacuum.

The white precipitate obtained is subjected to chromatography on a silica column and methylene chloride as eluant.

After evaporation of the elution solvant under vacuum, 5 g of pure white crystals are recovered (yield=80%) having a melting point of 66.degree. C.

The 13C and 1-H NMR spectra were as expected for the structure.

IR spectrum: 1730 cm-1 (ester) 1685 cm-1 and 1535 cm-1 (carbamate)

______________________________________Quantitative analysis: C.sub.36 H.sub.71 NO.sub.4 C % H % N % O %______________________________________Calculated 74.30 12.30 2.41 11.00Found 74.45 12.33 2.46 10.95______________________________________

EXAMPLE 2

Preparation of dodecyl N-carbohexadecyloxy-11-aminoundecanoate

Using the same procedure as in example 1 and using 2.1 g of lauryl, alcohol, 5.4 g of pure white crystals are obtained (yield=80%) having a melting point of 69.degree.-70.degree. C.

The 1-H NMR spectrum (250 MHz) corresponds with the expected structure.

IR spectrum: 1726 cm-1 (ester) 1685 cm-1 and 1551 cm-1 (carbamate)

______________________________________Quantitative analysis: C.sub.40 H.sub.79 NO.sub.4 C % H % N % O %______________________________________Calculated 75.29 12.48 2.20 10.03Found 75.22 12.51 2.27 10.18______________________________________

EXAMPLE 3

Preparation of tetradecyl N-carbohexadecyloxy-11-aminoundecanoate

Using the same procedure as in example 1, and using 2.4 g of tetradecanol, 5.6 g of pure white crystals are obtained (yield=80%) having a melting point of 73.degree. C.

The 1-H NMR spectrum (250 MHz) corresponds with the expected structure.

IR spectrum: 1727 cm-1 (ester) 1686 cm-1 and 1537 cm-1 (carbamate)

______________________________________Quantitative analysis: C.sub.42 H.sub.83 NO.sub.4 C % H % N % O %______________________________________Calculated 75.73 12.56 2.10 9.61Found 75.88 12.61 2.06 9.63______________________________________

EXAMPLE 4

Preparation of hexadecyl N-carbohexadecyloxy-11-aminoundecanoate

(i) Following the same procedure as that described in example 1 and using 2.7 g of hexadecanol, 5.9 g of pure white crystals are obtained (yield=80%) having a melting point of 76.degree. C.

The 13-C NMR spectrum corresponds to the expected structure.

IR spectrum: 1730 cm-1 (ester) 1685 cm-1 and 1536 cm-1 (carbamate)

______________________________________Quantitative analysis C.sub.44 H.sub.87 NO.sub.4 C % H % N % O %______________________________________Calculated 76.13 12.63 2.02 9.22Found 75.55 12.75 2.06 9.76______________________________________

(ii) 3.4 g of 1-bromohexadecane in 100 ml acetonitrile are added to 5 g of the sodium carboxylate obtained as intermediate in example A.

After having refluxed for 8 hours, the reaction medium is evaporated to dryness.

The white precipitate is subjected to chromatography on a silica column using methylene chloride as eluant.

After evaporation of the elution solvent under vacuum, 4.6 g (yield 65%) of pure white crystals are obtained, identical to those in (1) above.

EXAMPLE 5

Preparation of octadecyl N-carbohexadecyl-11-amino undecanoate

Following the procedure of example 1 and using 3.1 g of octadecanol, 6.1 g of pure white crystals (yield=80%) are obtained having a melting point of 78.degree. C.

The 1-H NMR spectrum (250 MHz) corresponds to the expected structure.

IR spectrum: 1726 cm-1 (ester) 1686 cm-1 and 1536 cm-1 (carbamate)

______________________________________Quantitative analysis C.sub.46 H.sub.91 NO.sub.4 C % H % N % O %______________________________________Calculated 76.50 12.70 1.94 8.86Found 76.57 12.69 2.01 8.89______________________________________

EXAMPLE 6

Preparation of docosyl N-carbohexadecyloxy-11-aminoundecanoate

Following the procedure of example 1 and using 3.6 g of docosanol, 6.6 g of pure white crystals (yield=80%) are obtained having a melting point of 81.degree.-82.degree. C.

The 1-H NMR spectrum (250 MHz) corresponds to the expected structure.

IR spectrum: 1726 cm-1 (ester) 1685 cm-1 and 1536 cm-1 (carbamate)

______________________________________Quantitative analysis C.sub.50 H.sub.99 NO.sub.4 C % H % N % O %______________________________________Calculated 77.16 12.82 1.80 8.22Found 77.19 12.85 1.79 8.13______________________________________

EXAMPLE 7

Preparation of triacontyle N-carbohexadecyloxy-11aminoundecanoate

Following the same procedure as in example 1, and using 4.90 g of triacontanol ("Unilin.TM. 425" by PETROLITE), 4.7 g of waxy crystals (50% yield) are obtained having a melting point of 69.5.degree.-71.degree. C.

The 13-C NMR spectrum corresponds to the expected structure.

IR spectrum: 1727 cm-1 (ester) 1686 cm-1 and 1537 cm-1 (carbamate)

EXAMPLE 8

Preparation of oleyl N-carbohexadecyloxy-11-aminoundecanoate

Following the same procedure as in example 1 and using 3.0 g of oleyl alcohol, 6.1 g of pure white crystals (80% yield) are obtained having a melting point of 62.degree. C.

The 1-H NMR spectra (250 MHz) correspond to the expected structure.

IR spectrum: 1726 cm-1 (ester) 1685 cm-1 and 1551 cm-1 (carbamate)

______________________________________Quantitative analysis C.sub.46 H.sub.89 NO.sub.4 C % H % N % O %______________________________________Calculated 76.71 12.46 1.94 8.89Found 76.83 12.37 1.96 8.66______________________________________

EXAMPLE 9

Preparation of isostearyl N-carbohexadecyloxy-11-aminoundecanoate

Following the procedure of example 1, and using 3.0 g isostearyl alcohol (REWO.TM. Aldol 66) 6.1 g of white crystals (80% yield) are obtained having a melting point of 68.degree..+-.2.degree. C.

The 13-C and 1-H NMR spectra (250 MHz) correspond to the expected structure.

IR spectrum: 1728 cm-1 (ester) 1686 cm-1 and 1537 cm-1 (carbamate)

______________________________________Quantitative analysis: C.sub.46 H.sub.91 NO.sub.4 C % H % N % O %______________________________________Calculated 76.50 12.70 1.94 8.86Found 76.60 12.82 1.98 9.10______________________________________

EXAMPLE 10

Preparation of benzyle N-carbohexadecyloxy-11-aminoundecanoate

Following the procedure of example 1, and using 1.2 g of benzyl alcohol, 4.8 g of pure white crystals (80% yield) are obtained having a melting point of 71.degree.-72.degree. C.

The 1-H NMR spectrum (250 MHz) corresponds to the expected structure.

IR spectrum: 1734 cm-1 (ester) 1684 cm-1 and 1529 cm-1 (carbomate)

______________________________________Quantitative analysis C.sub.35 H.sub.61 NO.sub.4 C % H % N % O %______________________________________Calculated 75.08 10.98 2.50 11.43Found 75.23 10.95 2.49 11.64______________________________________

EXAMPLE 11

Preparation of hexadecyl N-carbodecyloxy-11-aminoundecanoate

3.3 g of hexadecanol, 300 mg of paratoluene sulphonic acid and 80 ml of toluene are added to 5 g of the acid obtained in example B.

Dehydration is carried out by azeotopic entrainment for 16 hours, after which the reaction mixture is evaporated to dryness under vacuum.

The white precipitate obtained is subjected to chromatography on a silica column using methylene chloride as eluant.

After evaporation of the elution solvent under vacuum, 6.3 g of pure white crystals (80% yield) are recovered having a melting point of 65.degree. C.

The 1-H NMR spectrum corresponds to the expected structure.

IR spectrum: 1725 cm-1 (ester) 1635 cm-1 and 1685 cm-1 (carbamate)

______________________________________Examples of formulation______________________________________Example ALipstickRicin oil 72.5%Hexadecyl N-carbohexadecyloxy-11-aminoundecanoate 15%Mica-titanium 7%Talc q.s.p. 3%Titanium dioxide q.s.p. 2.5%Pigments q.sPerfume q.sExample BStickCodex cocoa butter 10%Ozokerite 24%Retined white paraffin 4%Codex ricin oil 8%Oleyl alcohol 6%Clear odourless lanolin 8%2-ethyl hexyl-p-methoxycinnamate 2%BHT (butyl hydroxytoluene) 0.025%BHA (butyl hydroxy anisole) 0.025%hexadecyl N-carbohexadecyloxy-11-aminoundecanoate 1%Perfume 0.8%Vaseline oil q.s.p 100%Example CAnhydrous nail varnishCopolymer of butyl methacrylate (70%) 24%and hydroxypropyl methacrylate (30%)Tributyl acetylcitrate 4%Butyl acetate 22.8%Ethyl acetate 9.8%Toluene 32.7%Ethanol 5.7%Octadecyl N-carbohexadecyloxy-11-aminoundecanoate 1%Example DAnhydrous nail varnishCopolymer of butyl methacrylate (50%) and 30%Hydroxypropyl methacrylate (50%)Tributyl acetylcitrate 7%Butyl acetate 20.2%Ethyl acetate 8.6%Toluene 28.9%Ethanol 5%Hexadecyl N-carbohexadecyloxy-11-aminoundecanoate 0.3%Example ESun cream, water-in-oilOctyl dodecanol 10%Magnesium stearate 4%Natural beeswax 5%Hydrogenated lanolin 1%Clear odourless lanolin 4%Sorbitan sesquioleate 4.5%Glycerol mono and distearate and potassium stearate 1%Vaseline oil 22%2-ethyl hexyl p-methoxycinnamate 5%Hexadecyl N-carbohexadecyloxy-11-aminoundecanoate 1%Preservatives 0,4%Perfume 0,6%Water q.s.p 100%Example FProtective handcreamMono- and diglyceride of isostearic acid esterified 5%by succinic acidVaseline oil 8%White vaseline 5%Capric and caprylic triglycerides 12.3%N-carbohexadecyloxy-11-aminoundecanoic acid 2%Magnesium sulphate 2%Glycerine 3%Preservatives 0.4%Water q.s.p. 100%Epprecht viscosity at 25.degree. C. = 3 Pa .multidot. SExample GNight renewal creamMono-and diglyceride of isostearic acid esterified 5%with succinic acidVaseline oil 8%White vaseline 5%Capric and caprylic triglycerides 12.3%Hexadecyl N-carbohexadecyloxy-11-aminoundecanoate 2%Magnesium sulphate 2%Glycerine 3%Preservatives 0.4%Water 100%Epprecht viscosity at 25.degree. C. = 4.3 Pa .multidot. SExample HBody milkEthers of dodecanediol (22 mol) and of 2%polyethyleneglycol (450E).beta.-hydroxyoctacosanyl 12-hydroxystearate 1%Polyglyceryl-2 sesquioleate 6%Vaseline oil 10.7%Volatile silicone oil 10.7%Capric and caprylic triglycerides 4%Hexadecyl N-carbohexadecyloxy-11-aminoundecanoate 1%Magnesium sulphate 2%Glycerine 3%Preservatives 0.4%Water q.s.p. 100%Epprecht viscosity at 25.degree. C. = 0.8 Pa .multidot. SExample IBody milkEthers of dodecanediol (22 mol) and of 2%polyethyleneglycol (450E).beta.-hydroxyoctacosanyl 12-hydroxystearate 1%Polyglyceryl-2 sesquioleate 6%Vaseline oil 10.7%Volatile silicone oil 10.7%Capric and caprylic triglycerides 4%N-carbohexadecyloxy-11-aminoundecanoic acid 1%Magnesium sulphate 2%Glycerine 3%Preservatives 0.4%Water q.s.p. 100%Epprecht viscosity at 25.degree. C.: 0.6 Pa .multidot. SExample JLight facial creamEthers of dodecanediol (22 mol) and of 2%polyethyleneglycol (450E).beta.-hydroxyoctacosanyl 12-hydroxystearate 1%Polyglyceryl-2 sesquioleate 6%Solid purcellin 4%Mixture of triglycerides of cocoa fatty acids 3.5%(C.sub.8 -C.sub.18)Light vaseline oil 6.5%Capric and caprylic tryglycerides 5%Volatile silicone oil 6%Hexadecyl N-carbohexadecyloxy-11-aminoundecanoate 2%Magnesium sulphate 2%Glycerine 3%Preservatives 0.4%Water q.s.p 100%Epprecht viscosity at 25.degree. C. = 1.4 Pa .multidot. S.Example KProtective day creamCopolymers of dodecylglycol/methoxy polyethylene- 3.2%glycol (220E).beta.-hydroxyoctacosanyl 12-hydroxystearate 0.5%Polyglyceryl-2 sesquioleate 4.8%Vaseline oil 11%Volatile silicone oil 8%Capric and caprylic triglycerides 4%N-carbohexadecyloxy-11-aminoundecanoic acid 2%Magnesium sulphate 2%Glycerine 3%Preservatives 0.4%Water q.s.p. 100%Epprecht viscosity at 25.degree. C. = 2 Pa .multidot. S.Example LLiquid moisturizing emulsionCopolymers of dodecylglycol/methoxy polyethylene- 3.2%glycol (220E).beta.-hydroxyoctacosanyl 12-hydroxystearate 0.5%Polyglyceryl-2 sesquioleate 4.8%Squalane 11%Volatile silicone oil 9%Jojoba oil 4%Hexadecyl N-carbohexadecyloxy 11-aminoundecanoate 1%Magnesium sulphate 2%Glycerine 3%Preservatives 0.4%Water q.s.p. 100%Epprecht viscosity at 25.degree. C. = 0.65 Pa .multidot. S.Example MOil-in-water creamKetostearyl alcohol and oxyethylenated 7%fatty alcoholsMixture of non-autoemulsionable glycerol 2%mono- and distearateCetyl alcohol 0.5%Hexadecyl N-carbohexadecyloxy-11-aminoundecanoate 1%Silicone oil 1.5%Vaseline oil 15%2-ethyl-hexyl-p-methoxycinnamate 5%Propyleneglycol 20%Preservatives 0.4%Perfume 0.6%Water q.s.p. 100%Example NWater-in-oil creamOctyl dodecanol 10%Magnesium stearate 4%Natural beeswax 5%Hydrogenated lanolin 1%Clear odourless lanolin 4%Sorbitan sesquioleate 4.5%Glycerol mono and distearate and potassium stearate 1%Vaseline oil 22%2-ethyl-hexyl-p-methoxycinnamate 5%Hexadecyl-N-carbodecyloxy-11-aminoundecanoate 1%Preservatives 0.4%Perfume 0.6%Water q.s.p. 100%Example OOil-in-water creamGlycerol monostearate 6%Pure stearyl alcohol 4%Vaseline oil 10%2-methyl-hexyl-p-methoxycinnamate 4%Silicone oil 1.5%Octyl-N-carbohexadecyloxy-11-aminoundecanoate 1%Pure codex glycerine 20%Preservatives 0.4%Perfume 0.6%Water q.s.p. 100%______________________________________

Claims

1. Alkyl esters of N-carboalkyloxy-11-amino undecanoic acids of general formula: ##STR7## in which: R is linear or branched C.sub.7-30 alkyl, linear or branched C.sub.4-22 alkenyl or a radical of formula: ##STR8## in which n is 0 to 5; R" is hydrogen or linear or branched C.sub.1-9 alkyl and

R' is linear C.sub.10-18 alkyl.

2. Compounds according to claim 1, characterised by the fact that the linear or branched C.sub.7-30 alkyl radical is octyl, dodecyl, tetradecyl, hexadecyl, octadecyl, hexyl-2-decyl, isostearyl, docosyl or triacontyl.

3. Compounds according to claim 1, characterised by the fact that the linear or branched C.sub.4-22 alkenyl radical is 10-undecenyl, 9-octadecenyl or 13-docosenyl.

4. Compounds according to claim 1, characterised by the fact that the radical of formula: ##STR9## is benzyl, phenethyl, p-xylyl or nonylphenyl.

5. Compounds according to claim 1, characterised by the fact that the linear C.sub.10-18 alkyl radical is dodecyl, tetradecyl, hexadecyl or octadecyl.

6. Compounds according to claim 1, characterised by the fact that R is linear or branched C.sub.14-20 alkyl.

7. Compounds according to claim 1 characterised by the fact that they are:

______________________________________octyl N-carbohexadecyloxy-11-aminoundecanoate,dodecyl N-carbohexadecyloxy-11-aminoundecanoate,tetradecyl N-carbohexadecyloxy-11-aminoundecanoate,hexadecyl N-carbohexadecyloxy-11-aminoundecanoate,octadecyl N-carbohexadecyloxy-11-aminoundecanoate,docosyl N-carbohexadecyloxy-11-aminoundecanoate,triacontyl N-carbohexadecyloxy-11-aminoundecanoate,oleyl N-carbohexadecyloxy-11-aminoundecanoate,isostearyl N-carbohexadecyloxy-11-aminoundecanoate,benzyl N-carbohexadecyloxy-11-aminoundecanoate, andhexadecyl N-carbodecyloxy-11-aminoundecanoate.______________________________________

8. A process for the preparation of alkyl esters of N-carboalkyloxy-11-aminoundecanoic acids, comprising reacting:

a fatty alcohol (R'OH) with an isocyanate of formula: ##STR10## in which R is a linear or branched C.sub.7-30 alkyl, linear or branched C.sub.4-22 alkenyl or a radical of formula: ##STR11## in which n is 0 to 5; R" is H, or a linear or branched C.sub.1-9 alkyl; and

R' is a linear C.sub.10-18 alkyl, with R additionally able to be hydrogen in which case the process further comprises esterifying the compounds thus obtained.

9. A process according to claim 8, characterised by the fact that the reaction is conducted in organic and/or aqueous solvent(s) in the presence of a base.

10. A process for the preparation of alkyl esters of N-carboalkyloxy-11-aminoundecanoic acids, comprising reacting an azolide of formula: ##STR12## with an amine of formula: ##STR13## in which R is a linear or branched C.sub.7-30 alkyl, linear or branched C.sub.4-22 alkenyl or a radical of formula: ##STR14## in which n is 0 to 5; R" is H, or a linear or branched C.sub.1-9 alkyl; and

R' is a linear C.sub.10-18 alkyl, with R additionally able to be hydrogen in which case the process further comprises esterifying the compounds thus obtained.

11. A process according to claim 10, wherein the reaction is conducted in organic and/or aqueous solvents in the presence of a base.