Hydroxyalkylaminoalkylamides and preparation and uses thereof

This invention relates to hydroxyalkylaminoalkylamides, the N-alkylated derivatives thereof, and the preparation and uses thereof.

In U.S. Pat. No. 3,714,249 there is disclosed and claimed 
hydroxyalkylaminoalkylamides as illustrated by the formula 
##STR1## 
which is prepared from benzonitrile and N-methyl aminoethanol by the 
process of claim 3 of U.S. Pat. No. 3,714,249 which is as follows: 
"3. A process for preparing a hydroxyalkylaminoalkylamide by reacting under 
anhydrous conditions in the absence of a catalyst, (a) a nitrile of 
structure R.sub.1 (CN).sub.n where R.sub.1 is selected from the group of 
alkyl of 1 to 10 carbon atoms, alkylene of two to 10 carbon atoms, phenyl, 
naphthyl, phenylene, lower alkyl substituted phenyl of from seven to 12 
carbon atoms, phenylalkyl of seven to 12 carbon atoms, and lower alkyl 
substituted phenylene of from seven to 12 carbon atoms, and n is a small 
integer of from one to three, with (b) an alkanolamine of structure 
##STR2## 
where R.sub.2 is H or lower alkyl and m is an integer of 2 to 4, said 
reaction being conducted at a temperature of from about 100.degree. to 
about 220.degree. C, at essentially atmospheric pressure, and at a mole 
ratio of alkanolamine per nitrile group exceeding 2 to 1, but less than 
about 20:1." 
The present process relates to such products, said products alkylated; and 
used thereof particularly as corrosion inhibitors. 
Two moles of alkanolamine will react with a nitrile to form novel linear 
hydroxylalkylaminoalkylamides having the structure 
##STR3## 
WHERE R.sub.1 is an alkyl, alkylene, aryl, aralkyl, or a lower alkyl 
substituted aryl group, R.sub.2 is H or lower alkyl, m is a integer of 
from 2 to 4 and n is a small integer of from about 1 to about 6, 
preferably 1 to 3. In accord with the process of the invention these 
compounds are made by reacting under anhydrous conditions in the absence 
of a catalyst, a nitrile of structure 
##STR4## 
WITH AN ALKANOLAMINE OF STRUCTURE 
##STR5## 
where R.sub.1, R.sub.2, m and n are above defined, said reaction being 
conducted at a temperature of from about 100.degree. to about 220.degree. 
C., at essentially atmospheric pressure and at a mole ratio of 
alkanolamine per nitrile group exceeding 2 to 1. 
Examples of useful nitriles include alkyl nitriles such as acetonitrile, 
propionitrile, n-butyronitrile, isobutyronitrile, and the like; alkylene 
dinitriles such as malononitrile, succinonitrile, glutaronitrile, 
adiponitrile and the like, aromatic nitriles such as benzonitrile, 
toluonitrile, terephthalonitrile, isophthalonitrile, 1-cyanonaphthalene, 
1,5-dicyanonaphthalene and the like. Aralkyl nitriles such as 
phenylacetonitrile, 1-naphthaleneacetonitrile, gamma-phenylbutryonitrile, 
and the like are also useful. Preferably, when R.sub.1 is an alkyl or 
alkylene group it will contain from two to ten carbon atoms. When R.sub.1 
is an aryl, aralkyl, or lower alkyl substituted aryl group it will 
contain, preferably, from seven carbon atoms (e.g., benzonitrile) to 
twelve carbon atoms (e.g., 1,5-dicyanononaphthalene). Preferred nitriles 
are the mono and dinitriles of the benzene series. 
Useful alkanolamines include hydroxyethylamine (ethanolamine), 
2-amino-1-propanol, hydroxybutylamine, 3-hydroxypropylamine, 
N-methylethanolamine, N-ethylethanol-amine, and the like. The R.sub.2 
substituent on the alkanolamine will usually be an alkyl group having no 
more than about six carbon atoms. 
In carrying out the reaction of the invention, the nitrile and alkanolamine 
are simply mixed and heated to reaction temperature, i.e., from about 
100.degree. to about 220.degree. C., and when reaction temperature for the 
particular combination of reactants is reached, ammonia is evolved. The 
reaction is conducted at atmospheric pressure, under anhydrous conditions 
and in the absence of any catalyst. While it is possible to carry out the 
reaction in certain solvent systems, solvents are not necessary. However, 
certain polar solvents such as dioxane, pyridine, the dimethylether of 
ethylene glycol and the like are very useful in that they permit reaction 
to occur at reflux and also permit easy solvent removal from the product 
by distillation. Other solvents such as dimethylsulfoxide, 
dimethylformamide, dimethylacetamide, and the like are also operable, but 
may be troublesome in hampering product recovery. Non-polar solvents such 
as aromatic hydrocarbons and high boiling aliphatic compounds are not 
useful as a reaction medium. 
It has been observed that if anhydrous conditions are not maintained, the 
reaction product contains only one alkanolamine moiety per cyano group 
instead of two. As indicated, the process requires that the mole ratio of 
alkanolamine to nitrile function exceed 2 to 1 and preferably will be 
between about 5:1 to 10:1. For practical purposes this ratio will not 
normally exceed about 20:1. 
Completion of reaction is readily determined by cessation of ammonia 
evolution (one mole of ammonia is evolved for each cyano group). The 
reaction mass is worked up by any conventional procedure to recover the 
product. This is conveniently done by first vacuum distilling off excess 
alkanolamine and recovering the residue product by standard 
crystallization procedures. Conventional separation procedures are also 
useful where the linear hydroxyalkylaminoalkylamide product is mixed with 
any by-products of the reaction. 
The hydroxyalkylaminoalkylamide products are white or wax-like solids 
having sharp melting points. They are generally insoluble in the usual 
organic solvents at room temperature, but have sufficient solubility at 
elevated temperatures to make them responsive to purification procedures 
by crystallization. Water solubility of the compounds is essentially 
complete at all proportions and such aqueous solutions show strong 
surfactant properties. 
Examples of typical compounds of the invention include the mono- and 
bis-amide compounds such as 2-hydroxy-ethylaminoethylbenzamide of 
structure 
EQU C.sub.6 H.sub.5 CONHCH.sub.2 CH.sub.2 NHCH.sub.2 CH.sub.2 OH, 
2-hydroxyethylaminoethyltoluamide, 2-hydroxypropylaminopropylbenzamide, 
bis(2-hydroxyethylaminoethyl) terephthalamide of structure 
##STR6## 
2-hydroxyethylaminoethylacetamide, 2-hydroxyhexylaminohexylbutyramide, and 
the like. 
In the present invention, the reaction of U.S. Pat. No. 3,714,249 has been 
extended to include the reaction product of ethylenically unsaturated 
nitriles with N-alkylalkanolamines to form similar compounds where in 
addition the N-alkylalkanolamine also reacts with the double bond of the 
unsaturated nitrile to form an N,N'-di(alkylalkanol). This is illustrated 
by the following equation: 
##STR7## 
This product can then be mono- or dialkylated. 
Thus, instead of a reaction with 2 moles of N-alkylethanolamine with 1 mole 
of nitrile, acrylonitrile reacts with 3 moles of N-alkylethanolamine. 
In addition to acrylonitrile, the following types of unsaturated nitriles 
can also be employed in the reaction 
##STR8## 
e.g., for example those of the general formula 
##STR9## 
where R' and R" are hydrogen or a substituted group for example alkyl, 
aryl, cycloalkyl, alkaryl, aralkyl, etc. Typical examples include 
##STR10## 
where R is alkyl, preferably methyl, such as methacrylonitrile 
EQU .phi.CH = CH CN 
where .phi. is an aryl group preferably phenyl such as cinnamonitrile. 
In addition, we have also discovered that the R.sub.2 group of the 
alkanolamine can be a substituted alkyl group. For example, R.sub.2 may be 
another alkanol group such as dialkanolamines, such as diethanolamines HN 
(CH.sub.2 CH.sub.2 OH).sub.2. 
The N-substituted group employed in forming the quaternaries of this 
invention include not only alkyl groups but also cycloalkyl, aryl, 
aralkyl, oxyalkyl, alkenyl, etc. The substituted group may contain about 
1-30 or more carbons, such as from about 1 to 24 carbons, for example from 
about 1 to 18 carbons, but preferably from about 1 to 12 carbons. 
In the preferred embodiment, at least one group containing at least about 6 
or more carbons is employed such as from about 8 to 12 carbons. 
The anion may be any suitable group such as halide, sulfate, carboxylates, 
etc., but is preferably chloride. 
In general, the amines are alkylated by the following procedure. 
The aminoamide is dissolved in a solvent and heated at 
60.degree.-180.degree. for 2-24 hrs. Suitable solvents include alcohols, 
methanol ethanol, n-propanol, isopropanol, butanol, etc., water, dimethyl 
formamide, dimethylsulfoxide, etc. Alternatively, the aminoamides can be 
alkylated without solvents simply by heating the aminoamide and alkylating 
reagent at 50.degree.-140.degree. for example. All temperatures are stated 
in .degree. C. 
The nitrile/alkanolamine reaction is illustrated as follows: 
##STR11## 
The alkylation is illustrated as follows: 
##STR12## 
We have extended the reaction to acrylonitrile where the reaction proceeds 
as follows: 
##STR13## 
This can then be mono- or dialkylated.

The following examples are presented to illustrate the preparation of the 
hydroxyalkylaminoalkylamides. 
EXAMPLE 1 
Benzonitrile (58.7 g, 0.57 mole) and 2-(methyl amino)-ethanol (129 g, 1.72 
mole) were stirred at 150.degree.-180.degree. (reflux) for 301/2 hrs. 
under a continuous sweep of Nitrogen. Evolution of NH.sub.3 was evident 
during the reaction. The resulting mixture was distilled under vacuum to 
remove the excess amine. The viscous reaction product (115.4 g) was found 
to have the structure 
##STR14## 
which in hydrolysis yields benzoic acid and the amine, 
##STR15## 
EXAMPLE 2 
Benzonitrile (34.3 g, 0.33 mole) and diethanolamine (105.1 g, 1 mole) were 
stirred at 150.degree.-180.degree. for 26 hrs. Anhydrous conditions were 
maintained by a continuous nitrogen sweep. Strong evolution of NH.sub.3 
was evident during the course of the reaction. The resulting mixture was 
distilled under vacuum to remove excess amine yielding 84.2 g of viscous 
oil. The structure of the product is: 
##STR16## 
EXAMPLE 3 
Benzonitrile (103 g, 1 mole) and monoethanolamine (183.3 g, 3 mole, R.sub.2 
=H) were stirred at 150.degree.-180.degree. for 27 hrs. under anhydrous 
conditions (via N.sub.2 sweep) with rapid evolution of NH.sub.3. The 
excess monoethanolamine was removed by vacuum distillation to yield 195.1 
g of viscous oil. The product is largely: 
##STR17## 
EXAMPLE 4 
Acrylonitrile (35.3 g, 0.67 mole) was added slowly (15 min) to 
2-(methylamino)-ethanol (150.2 g, 2 mole). The exothermic reaction was 
maintained at 50.degree. by a water bath. After stirring at room temp. for 
30 min. the mixture was heated at 150.degree.-180.degree. for 47 hrs. 
Distillation under vacuum yielded only 5 g of excess amine leaving 112.5 g 
of viscous product. 
The product was shown to be 
##STR18## 
by hydrolysis with 10% sodium hydroxide solution which yielded 
##STR19## 
EXAMPLE 5 
Acrylonitrile (16.8 g, 0.32 mole) was added to diethanolamine (100 g, 0.95 
mole) with an exothermic reaction occurring that was controlled at 
50.degree. by water bath cooling. After stirring the resulting mixture for 
15 min. at room temperature it was heated at 150.degree.-180.degree. for 
25 hrs. Vacuum distillation of the reaction product gave only 6 g of 
excess amine and 82.9 g of a viscous oil. 
The structure was shown to be 
##STR20## 
EXAMPLE 6 
Acrylonitrile (43.5 g, 0.82 mole) was added to monoethanolamine (150 g, 
2.45 mole) with water bath cooling to control the exothermic reaction. 
After stirring the resulting mixture at room temperature for 30 min. it 
was heated at 150.degree.-180.degree. for 9 hrs. to yield 51.8 g of 
viscous oil after removal of slight excess of amine. 
The product is mainly 
##STR21## 
The following examples are presented to illustrate the preparation of 
alkylated derivatives. 
EXAMPLE 7 
Benzyl chloride (38 g, 0.3 mole) was added at 100.degree. to the amide 
(62.8 g, 0.3 mole) of Example 1 during 20 mins. The mixture was stirred at 
100.degree. for 6 hrs. to yield the expected benzyl derivative 99.8 g. 
##STR22## 
The following table summarizes additional alkylated derivatives prepared in 
the manner of Example 7. 
______________________________________ 
Example No. Amino amide Alkylating reagent 
______________________________________ 
8 Ex. 2 PhCH.sub.2 Cl 
9 Ex. 3 PhCH.sub.2 Cl 
10 Ex. 4 PhCH.sub.2 Cl 
11 Ex. 5 PhCH.sub.2 Cl 
12 Ex. 6 PhCH.sub.2 Cl 
______________________________________ 
USE IN BRINES 
This phase of the invention relates to the prevention of corrosion in 
systems containing a corrosive aqueous medium, and most particularly in 
systems containing brines. 
More particularly, this invention relates to the prevention of corrosion in 
the secondary recovery of petroleum by water flooding and in the disposal 
of waste water and brine from oil and gas wells. Still more particularly, 
this invention relates to a process of preventing corrosion in water 
flooding and in the disposal of waste water and brine from oil and gas 
wells which is characterized by injecting into an underground formation an 
aqueous solution containing minor amounts of compositions of this 
invention, in sufficient amounts to prevent the corrosion of metals 
employed in such operation. This invention also relates to corrosion 
inhibited brine solutions of these compounds. 
When an oil well ceases to flow by the natural pressure in the formation 
and/or substantial quantities of oil can no longer be obtained by the 
usual pumping methods, various processes are sometimes used for the 
treatment of the oil-bearing formation in order to increase the flow of 
the oil. These processes are usually described as secondary recovery 
processes. One such process which is used quite frequently is the water 
flooding process wherein water is pumped under pressure into what is 
called an "injection well" and oil, along with quantities of water, that 
have been displaced from the formation, are pumped out of an adjacent well 
usuably referred to as a "producing well." The oil which is pumped from 
the producing well is then separated from the water that has been pumped 
from the producing well and the water is pumped to a storage reservoir 
from which it can again be pumped into the injection well. Supplementary 
water from other sources may also be used in conjunction with the produced 
water. When the storage reservoir is open to the atmosphere and the oil is 
subject to aeration this type of water flooding system is referred to 
herein as an "open water flooding system." 
Because of the corrosive nature of oil field brines, to economically 
produce oil by water flooding, it is necessary to prevent or reduce 
corrosion since corrosion increases the cost thereof by making it 
necessary to repair and replace such equipment at frequency intervals. 
We have now discovered a method of preventing corrosion in systems 
containing a corrosive aqueous media, and most particularly in systems 
containing brines, which is characterized by employing the compositions of 
this invention. 
We have also discovered an improved process of protecting from corrosion 
metallic equipment employed in secondary oil recovery by water flooding 
such as injection wells, transmission lines, filters, meters, storage 
tanks, and other metallic implements employed therein and particularly 
those containing iron, steel, and ferrous alloys, such process being 
characterized by employing in water flood operation the compositions of 
this invention. 
This phase of the invention then is particularly concerned with preventing 
corrosion in a water flooding process characterized by the flooding medium 
containing an aqueous or an oil field brine solution of these compounds. 
In many oil fields large volumes of water are produced and must be disposed 
of where water flooding operations are not in use or where water flooding 
operations cannot handle the amount of produced water. Most states have 
laws restricting pollution of streams and land with produced waters, and 
oil producers must then find some method of disposing of the waste 
produced salt water. In many instances, therefore, the salt water is 
disposed of by injecting the water into permeable low pressure strata 
below the fresh water level. The formation into which the water is 
injected is not the oil producing formation and this type of disposal is 
defined as salt water disposal or waste water disposal. The problems of 
corrosion of equipment are analagous to those encountered in the secondary 
recovery operation by water flooding. 
The compositions of this invention can also be used in such water disposal 
wells thus providing a simple and economical method of solving the 
corrosion problems encountered in disposing of unwanted water. 
Water flood and waste disposal operations are too well known to require 
further elaboration. In essence, in the present process, the flooding 
operation is effected in the conventional manner except that the flooding 
medium contains a minor amount of the compound of this invention, 
sufficient to prevent corrosion, in concentrations of about 10 p.p.m. to 
10,000 p.p.m., or more, for example, about 50 to 5,000 p.p.m., but 
preferably about 15 to 1,500 p.p.m. The upper limiting amount of the 
compounds is determined by economic considerations. Since the success of a 
water flooding operation manifestly depends upon its total cost being less 
than the value of the additional oil recovered from the oil reservoir, it 
is quite important to use as little as possible of these compounds 
consistent with optimum corrosion inhibition. Optimum performance is 
generally obtained employing about 5 - 100 p.p.m. Since these compounds 
are themselves inexpensive and are used in low concentrations, they 
enhance the success of a flood operation by lowering the cost thereof. 
While the flooding medium employed in accordance with the present invention 
contains water or oil field brine and the compounds, the medium may also 
contain other materials. For example, the flooding medium may also contain 
other agents such as surface active agents or detergents which aid in 
wetting throughout the system and also promote the desorption of residual 
oil from the formation, sequestering agents which prevent the deposition 
of calcium and/or magnesium compounds in the interstices of the formation, 
bactericides which prevent the formation from becoming plugged through 
bacterial growth, tracers, etc. Similarly, they may be employed in 
conjunction with any of the operating techniques commonly employed in 
water flooding and water disposal processes, for example five spot 
flooding, peripheral flooding, etc., and in conjunction with other 
secondary recovery methods. 
The following examples illustrate the use of the compositions of this 
invention as corrosion inhibitors. 
______________________________________ 
Conditions: 2% NaCl Solution 
Atm. Pressure 
Room Temperature 
Constant CO.sub.2 Aparge (Coleman 
Instrument Grade) 
Constant Stirring 
500 p.p.m. of inhibitor based 
on active component 
Corrosion Rate (mpy) 
Example 
1 hr. (Protection) 
24 hr. (Protection) 
______________________________________ 
2 26 (81%) 6.8 (96%) 
5 20 (86%) 16 (90%) 
7 35 (75%) 41 (76%) 
8 10 (93%) 2.4 (99%) 
9 5.4 (96%) 3.4 (98%) 
11 54 (61%) 38 (77%) 
12 56 (60%) 28 (83%) 
Blank 140 168 
______________________________________