Polyalkyl and polyalkenyl aromatic amides and fuel compositions containing the same

Polyalkyl and polyalkenyl aromatic amides having the formula: ##STR1## or a fuel-soluble salt thereof; wherein A is hydroxy, nitro, amino, N-alkylamino wherein the alkyl group contains 1 to 6 carbon atoms, or N,N-dialkylamino wherein each alkyl group independently contains 1 to 6 carbon atoms; R.sub.1 and R.sub.2 are each independently hydrogen, hydroxy, lower alkyl having 1 to 6 carbon atoms, or lower alkoxy having 1 to 6 carbon atoms; R.sub.3 is hydrogen or lower alkyl having 1 to 6 carbon atoms; R.sub.4 is hydrogen or an acyl group of the formula: ##STR2## wherein A.sub.1 is hydroxy, nitro, amino, N-alkylamino wherein the alkyl group contains 1 to 6 carbon atoms, or N,N-dialkylamino wherein each alkyl group independently contains 1 to 6 carbon atoms; R.sub.6 and R.sub.7 are each independently hydrogen, hydroxy, lower alkyl having 1 to 6 carbon atoms, or lower alkoxy having 1 to 6 carbon atoms; R.sub.5 is a polyalkyl or polyalkenyl group having an average molecular weight in the range of about 450 to 5,000; n is an integer from 0 to 2; and x is an integer from 2 to 5. The polyalkyl and polyalkenyl aromatic amides of formula I are useful as fuel additives for the prevention and control of engine deposits.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to novel hydroxy, nitro, and amino aromatic 
compounds. More particularly, this invention relates to novel polyalkyl 
and polyalkenyl hydroxy, nitro, and amino aromatic amides and their use in 
fuel compositions to prevent and control engine deposits. 
2. Description of the Related Art 
It is well known that automobile engines tend to form deposits on the 
surface of engine components, such as carburetor ports, throttle bodies, 
fuel injectors, intake ports, and intake valves, due to the oxidation and 
polymerization of hydrocarbon fuel. These deposits, even when present in 
relatively minor amounts, often cause noticeable driveability problems, 
such as stalling and poor acceleration. Moreover, engine deposits can 
significantly increase an automobile's fuel consumption and production of 
exhaust pollutants. Therefore, the development of effective fuel 
detergents or "deposit control" additives to prevent or control such 
deposits is of considerable importance and numerous such materials are 
known in the art. 
For example, aliphatic hydrocarbon-substituted phenols are known to reduce 
engine deposits when used in fuel compositions. U.S. Pat. No. 3,849,085, 
issued Nov. 19, 1974 to Kreuz et al., discloses a motor fuel composition 
comprising a mixture of hydrocarbons in the gasoline boiling range 
containing about 0.01 to 0.25 volume percent of a high molecular weight 
aliphatic hydrocarbon-substituted phenol in which the aliphatic 
hydrocarbon radical has an average molecular weight in the range of about 
500 to 3,500. This patent teaches that gasoline compositions containing 
minor amounts of an aliphatic hydrocarbon-substituted phenol not only 
prevent or inhibit the formation of intake valve and port deposits in a 
gasoline engine, but also enhance the performance of the fuel composition 
in engines designed to operate at higher operating temperatures with a 
minimum of decomposition and deposit formation in the manifold of the 
engine. 
Similarly, U.S. Pat. No. 4,134,846, issued Jan. 16, 1979 to Machleder et 
al., discloses a fuel additive composition comprising a mixture of (1) the 
reaction product of an aliphatic hydrocarbon-substituted phenol, 
epichlorohydrin and a primary or secondary mono- or polyamine, and (2) a 
polyalkylene phenol. This patent teaches that such compositions show 
excellent carburetor, induction system and combustion chamber detergency 
and, in addition, provide effective rust inhibition when used in 
hydrocarbon fuels at low concentrations. 
Amino phenols are also known to function as detergents/dispersants, 
antioxidants, and anti-corrosion agents when used in fuel compositions. 
U.S. Pat. No. 4,320,021, issued Mar. 16, 1982 to R. M. Lange, for example, 
discloses amino phenols having at least one substantially saturated 
hydrocarbon-based substituent of at least 30 carbon atoms. The amino 
phenols of this patent are taught to impart useful and desirable 
properties to oil-based lubricants and normally liquid fuels. 
Nitro phenols have also been employed as fuel additives. For example, U.S. 
Pat. No. 4,347,148, issued Aug. 31, 1982 to K. E. Davis, discloses nitro 
phenols containing at least one aliphatic substituent having at least 
about 40 carbon atoms. The nitro phenols of this patent are taught to be 
useful as detergents, dispersants, antioxidants, and demulsifiers for 
lubricating oil and fuel compositions. 
Similarly, U.S. Pat. No. 3,434,814, issued Mar. 25, 1969 to M. Dubeck et 
al., discloses a liquid hydrocarbon fuel composition containing a major 
quantity of a liquid hydrocarbon of the gasoline boiling range and a minor 
amount sufficient to reduce exhaust emissions and engine deposits of an 
aromatic nitro compound having an alkyl, aryl, aralkyl, alkanoyloxy, 
alkoxy, hydroxy, or halogen substituent. 
Poly(oxyalkylene) esters of amino- and nitrobenzoic acids are also known in 
the art. For example, U.S. Pat. No. 2,714,607, issued Aug. 2, 1955 to M. 
Matter, discloses polyethoxy esters of aminobenzoic acids, nitrobenzoic 
acids, and other isocyclic acids. These polyethoxy esters are taught to 
have excellent pharmacological properties and to be useful as anesthetics, 
spasmolytics, analeptics, and bacteriostatics. 
Similarly, U.S. Pat. No. 5,090,914, issued Feb. 25, 1992 to D. T. Reardan 
et al., discloses poly(oxyalkylene) aromatic compounds having an amino or 
hydrazinocarbonyl substituent on the aromatic moiety and an ester, amide, 
carbamate, urea, or ether linking group between the aromatic moiety and 
the poly(oxyalkylene) moiety. These compounds are taught to be useful for 
modifying macromolecular species such as proteins and enzymes. 
U.S. Pat. No. 4,328,322, issued Sep. 22, 1980 to R. C. Baron, discloses 
amino- and nitrobenzoate esters of oligomeric polyols, such as 
poly(ethylene) glycol. These materials are used in the production of 
synthetic polymers by reaction with a polyisocyanate. 
In addition, U.S. Pat. No. 4,231, , 759 issued Nov. 4, 1980 to Udelhofen et 
al., discloses a fuel additive composition comprising the Mannich 
condensation product of (1) a high molecular weight alkyl-substituted 
hydroxyaromatic compound wherein the alkyl group has a number average 
molecular weight of about 600 to about 3,000, (2) an amine, and (3) an 
aldehyde. This patent teaches that such Mannich condensation products 
provide carburetor cleanliness when employed alone, and intake valve 
cleanliness when employed in combination with a hydrocarbon carrier fluid. 
U.S. Pat. No. 4,859,210, issued Aug. 22, 1989 to Franz et al., discloses 
fuel compositions containing (1) one or more polybutyl or polyisobutyl 
alcohols wherein the polybutyl or polyisobutyl group has a number average 
molecular weight of 324 to 3,000, or (2) a poly(alkoxylate) of the 
polybutyl or polyisobutyl alcohol, or (3) a carboxylate ester of the 
polybutyl or polyisobutyl alcohol. This patent further teaches that when 
the fuel composition contains an ester of a polybutyl or polyisobutyl 
alcohol, the ester-forming acid group may be derived from saturated or 
unsaturated, aliphatic or aromatic, acyclic or cyclic, mono- or 
polycarboxylic acids. 
U.S. Pat. No. 3,285,855, issued Nov. 15, 1966 to Dexter et al., discloses 
alkyl esters of dialkyl hydroxybenzoic and hydroxyphenylalkanoic acids 
wherein the ester moiety contains from 6 to 30 carbon atoms. This patent 
teaches that such esters are useful for stabilizing polypropylene and 
other organic material normally subject to oxidative deterioration. 
Similar alkyl esters containing hindered dialkyl hydroxyphenyl groups are 
disclosed in U.S. Pat. No. 5,196,565, which issued Mar. 23, 1993 to Ross. 
U.S. Pat. No. 5,196,142, issued Mar. 23, 1993 to Mollet et al., discloses 
alkyl esters of hydroxyphenyl carboxylic acids wherein the ester moiety 
may contain up to 23 carbon atoms. This patent teaches that such compounds 
are useful as antioxidants for stabilizing emulsion-polymerized polymers. 
It has now been discovered that certain polyalkyl and polyalkenyl hydroxy, 
nitro, and amino aromatic amides provide excellent control of engine 
deposits, especially intake valve deposits, when employed as fuel 
additives in fuel compositions. 
SUMMARY OF THE INVENTION 
The present invention provides novel polyalkyl and polyalkenyl hydroxy, 
nitro, and amino aromatic amides which are useful as fuel additives for 
the prevention and control of engine deposits, particularly intake valve 
deposits. 
The polyalkyl and polyalkenyl hydroxy, nitro, and amino aromatic amides of 
the present invention have the formula: 
##STR3## 
or a fuel-soluble salt thereof; wherein A is hydroxy, nitro, amino, 
N-alkylamino wherein the alkyl group contains 1 to 6 carbon atoms, or 
N,N-dialkylamino wherein each alkyl group independently contains 1 to 6 
carbon atoms; R.sub.1 and R.sub.2 are each independently hydrogen, 
hydroxy, lower alkyl having 1 to 6 carbon atoms, or lower alkoxy having 1 
to 6 carbon atoms; R.sub.3 is hydrogen or lower alkyl having 1 to 6 carbon 
atoms; R.sub.4 is hydrogen or an acyl group of the formula: 
##STR4## 
wherein A.sub.1 is hydroxy, nitro, amino, N-alkylamino wherein the alkyl 
group contains 1 to 6 carbon atoms, or N,N-dialkylamino wherein each alkyl 
group independently contains 1 to 6 carbon atoms; R.sub.6 and R.sub.7 are 
each independently hydrogen, hydroxy, lower alkyl having 1 to 6 carbon 
atoms, or lower alkoxy having 1 to 6 carbon atoms; R.sub.5 is a polyalkyl 
or polyalkenyl group having an average molecular weight in the range of 
about 450 to 5,000; n is an integer from 0 to 2; and x is an integer from 
2 to 5. 
The present invention further provides a fuel composition comprising a 
major amount of hydrocarbons boiling in the gasoline or diesel range and 
an effective deposit-controlling amount of a polyalkyl or polyalkenyl 
hydroxy, nitro, or amino aromatic amide of the present invention. 
The present invention additionally provides a fuel concentrate comprising 
an inert stable oleophilic organic solvent boiling in the range of from 
about 150.degree. F. to 400.degree. F. (about 65.degree. C. to 205.degree. 
C.) and from about 10 to 70 weight percent of a polyalkyl or polyalkenyl 
hydroxy, nitro, or amino aromatic amide of the present invention. 
Among other factors, the present invention is based on the surprising 
discovery that certain polyalkyl and polyalkenyl hydroxy, nitro, and amino 
aromatic amides, when employed as fuel additives in fuel compositions, 
provide excellent control of engine deposits, especially on intake valves, 
and produce.

DETAILED DESCRIPTION OF THE INVENTION 
The fuel additives provided by the present invention have the general 
formula: 
##STR5## 
wherein A, R.sub.1, R.sub.3, R.sub.3, R.sub.4, R.sub.5, n, and x are as 
defined hereinabove. 
In formula I, above, A is preferably a hydroxy, nitro, or amino group. More 
preferably, A is a hydroxy group. 
Preferably, R.sub.1 is hydrogen, hydroxy, or lower alkyl having 1 to 4 
carbon atoms. More preferably, R.sub.1 is hydrogen or hydroxy. Most 
preferably, R.sub.1 is hydrogen. 
R.sub.2 and R.sub.3 are preferably hydrogen. 
R.sub.4 is hydrogen or an acyl group of the formula: 
##STR6## 
wherein A.sub.1 is preferably a hydroxy, nitro, or amino group. More 
preferably, A.sub.1 is a hydroxy group. Preferably, R.sub.6 is hydrogen, 
hydroxy, or lower alkyl having 1 to 4 carbon atoms. More preferably, 
R.sub.6 is hydrogen. R.sub.7 is preferably hydrogen. 
Preferably, R.sub.5 is a polyalkyl or polyalkenyl group having an average 
molecular weight in the range of about 450 to 5,000, more preferably about 
500 to 3,000, and most preferably about 600 to 2,000. 
Preferably, n is 0 or 1. 
Preferably, x is an integer from 2 to 3. More preferably, x is 2. 
A preferred group of polyalkyl and polyalkenyl aromatic amides are those of 
formula I wherein R.sub.1 and R.sub.6 are hydrogen, hydroxy, or lower 
alkyl having 1 to 4 carbon atoms; R.sub.2, R.sub.3, and R.sub.7 are 
hydrogen; n is 1 or 2; and x is 2. 
Another preferred group of polyalkyl and polyalkenyl aromatic amides are 
those of formula I wherein R.sub.1 and R.sub.6 are hydrogen, hydroxy, or 
lower alkyl having 1 to 4 carbon atoms; R.sub.2, R.sub.3, and R.sub.7 are 
hydrogen; and n is 0. 
When A and A.sub.1 are an N-alkylamino group, the alkyl group of the 
N-alkylamino moiety preferably contains 1 to 4 carbon atoms. More 
preferably, the alkyl group is methyl or ethyl. For example, particularly 
preferred N-alkylamino groups are N-methylamino and N-ethylamino groups. 
Most preferably, the alkyl group is methyl. 
Similarly, when A and A.sub.1 are an N,N-dialkylamino group, each alkyl 
group of the N,N-dialkylamino moiety preferably contains 1 to 4 carbon 
atoms. More preferably, each alkyl group is either methyl or ethyl. For 
example, particularly preferred N,N-dialkylamino groups are 
N,N-dimethylamino, N-ethyl-N-methylamino, and N,N-diethylamino groups. 
Most preferably, each alkyl group is methyl. 
A further preferred group of polyalkyl and polyalkenyl aromatic amides are 
those wherein A and A.sub.1 are hydroxy, R.sub.1 and R.sub.6 are hydrogen 
or hydroxy, R.sub.2, R.sub.3, and R.sub.7 are hydrogen, n is 1 and x is 2. 
Another preferred group of polyalkyl and polyalkenyl aromatic amides are 
those wherein A is hydroxy, R.sub.1 is hydrogen or hydroxy, R.sub.2 and 
R.sub.3 are hydrogen, and n is 0. 
It is especially preferred that the hydroxy, nitro, amino, N-alkylamino, or 
N,N-dialkylamino substituent present in the aromatic moiety of the 
polyalkyl and polyalkenyl aromatic amides of this invention be situated in 
a meta or para position relative to the polyalkyl or polyalkenyl amide 
moiety. When R.sub.1 and R.sub.6 is a hydroxy or lower alkyl having 1 to 4 
carbon atoms, it is particularly preferred that the hydroxy or lower alkyl 
groups be in a meta or para position relative to the polyalkyl or 
polyalkenyl amide moiety and in an ortho position relative to the hydroxy, 
nitro, amino, N-alkylamino, or N,N-dialkylamino substituent. 
The polyalkyl and polyalkenyl aromatic amides of the present invention will 
generally have a sufficient molecular weight so as to be non-volatile at 
normal engine intake valve operating temperatures (about 200 .degree. C. 
to 250.degree. C.). Typically, the molecular weight of the polyalkyl and 
polyalkenyl aromatic amides of this invention will range from about 450 to 
about 5,000, preferably from 500 to 3,000, more preferably from 600 to 
2,000. 
Fuel-soluble salts of the polyalkyl and polyalkenyl hydroxy aromatic amides 
of the present invention are also contemplated to be useful for preventing 
or controlling deposits. Such salts include alkali metal, alkaline earth 
metal, ammonium, substituted ammonium, and sulfonium salts. Preferred 
metal salts are the alkali metal salts, particularly the sodium and 
potassium salts, and the substituted ammonium salts, particularly 
tetraalkyl-substituted ammonium salts, such as the tetrabutylammonium 
salts. 
Fuel-soluble salts of the polyalkyl and polyalkenyl amino aromatic amides 
of the present invention can be readily prepared for those compounds 
containing an amino, N-alkylamino, or N,N-dialkylamino group and such 
salts are contemplated to be useful for preventing or controlling engine 
deposits. Suitable salts include, for example, those obtained by 
protonating the amino moiety with a strong organic acid, such as an alkyl- 
or arylsulfonic acid. Preferred salts are derived from toluenesulfonic 
acid and methanesulfonic acid. 
Definitions 
As used herein, the following terms have the following meanings unless 
expressly stated to the contrary. 
The term "amino" refers to the group: --NH.sub.2. 
The term "N-alkylamino" refers to the group: --NHR.sub.a wherein R.sub.a is 
an alkyl group. The term "N,N-dialkylamino" refers to the group: 
--NR.sub.b R.sub.c, wherein R.sub.b and R.sub.c are alkyl groups. 
The term "alkyl" refers to both straight- and branched-chain alkyl groups. 
The term "lower alkyl" refers to alkyl groups having 1 to about 6 carbon 
atoms and includes primary, secondary, and tertiary alkyl groups. Typical 
lower alkyl groups include, for example, methyl, ethyl, n-propyl, 
isopropyl, n-butyl, sec-butyl, t-butyl, n-pentyl, n-hexyl, and the like. 
The terms "polyalkyl" and "polyalkenyl" refer to alkyl and alkenyl groups 
which are generally derived from polyolefins which are polymers or 
copolymers of mono-olefins, particularly 1-mono-olefins, such as ethylene, 
propylene, butylene, and the like. Preferably, the mono-olefin employed 
will have 2 to about 24 carbon atoms, and more preferably, about 3 to 
carbon atoms. More preferred mono-olefins include propylene, butylene, 
particularly isobutylene, 1-octene, and 1-decene. Polyolefins prepared 
from such mono-olefins include polypropylene, polybutene, especially 
polyisobutene, and the polyalphaolefins produced from 1-octene and 
1-decene. 
General Synthetic Procedures 
The polyalkyl and polyalkenyl hydroxy, nitro, and amino aromatic amides of 
this invention may be prepared by the following general methods and 
procedures. It should be appreciated that where typical or preferred 
process conditions (e.g., reaction temperatures, times, mole ratios of 
reactants, solvents, pressures, etc.) are given, other process conditions 
may also be used unless otherwise stated. Optimum reaction conditions may 
vary with the particular reactants or solvents used, but such conditions 
can be determined by one skilled in the art by routine optimization 
procedures. 
Moreover, those skilled in the art will recognize that it may be necessary 
to block or protect certain functional groups while conducting the 
following synthetic procedures. In such cases, the protecting group will 
serve to protect the functional group from undesired reactions or to block 
its undesired reaction with other functional groups or with the reagents 
used to carry out the desired chemical transformations. The proper choice 
of a protecting group for a particular functional group will be readily 
apparent to one skilled in the art. Various protecting groups and their 
introduction and removal are described, for example, in T. W. Greene and 
P. G. M. Wuts, Protective Groups in Organic Synthesis, Second Edition, 
Wiley, New York, 1991, and references cited therein. 
In the present synthetic procedures, a hydroxy group will preferably be 
protected, when necessary, as the benzyl or tert-butyldimethylsilyl ether. 
Introduction and removal of these protecting groups is well described in 
the art. Amino groups may also require protection and this may be 
accomplished by employing a standard amino protecting group, such as a 
benzyloxycarbonyl or a trifluoroacetyl group. Additionally, as will be 
discussed in further detail hereinbelow, the polyalkyl and polyalkenyl 
aromatic amides of this invention having an amino group on the aromatic 
moiety will generally be prepared from the corresponding nitro derivative. 
Accordingly, in many of the following procedures, a nitro group will serve 
as a protecting group for the amino moiety. 
The polyalkyl and polyalkenyl aromatic amides of the present invention 
having the formula: 
##STR7## 
wherein A, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, n, and x are as 
defined above, may be prepared by conventional reaction conditions by 
reacting an acyl halide having the formula: 
##STR8## 
wherein R.sub.1, and R.sub.2 are as defined above, R.sub.8 is a nitro or 
protected hydroxy or amino group, and Z is a halide, such as chloride or 
bromide, with a polyalkyl or polyalkenyl substituted amine having the 
formula: 
##STR9## 
wherein R.sub.3, R.sub.5, n, and x are as defined above. 
A. Preparation of the Acyl Halide 
Acyl halides of formula II may be prepared from the corresponding aromatic 
carboxylic acids by first protecting the hydroxy or amino groups as 
necessary to form a carboxylic acid having the formula: 
##STR10## 
wherein R.sub.1 and R.sub.2 are as defined above and R.sub.8 is nitro or a 
suitably protected hydroxy or amino group. 
The aromatic carboxylic acids which are first protected and then converted 
to the corresponding acyl halide are either known compounds or can be 
prepared from known compounds by conventional procedures. Representative 
aromatic carboxylic acids suitable for use as starting materials include, 
for example, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 
4-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,4,5-trihydroxybenzoic 
acid, 3-hydroxy-4-methoxybenzoic acid, 4-hydroxy-3-methoxybenzoic acid, 
3-t-butyl-4-hydroxybenzoic acid, 3,5-di-t-butyl-4-hydroxybenzoic acid, 
2-nitrobenzoic acid, 3-nitrobenzoic acid, 4-nitrobenzoic acid, 
3-hydroxy-4-nitrobenzoic acid, 4-hydroxy-3-nitrobenzoic acid, 
2-aminobenzoic acid (anthranilic acid), 3-aminobenzoic acid, 
4-aminobenzoic acid, 3-amino-4-hydroxybenzoic acid, 
4-amino-3-hydroxybenzoic acid, 3-amino-4-methoxybenzoic acid, 
4-amino-3-methoxybenzoic acid, 4-amino-3-methylbenzoic acid, 
4-amino-3,5-di-t-butylbenzoic acid, 3-(N-methylamino) benzoic acid, 
4-(N-methylamino)benzoic acid, 3-(N-ethylamino) benzoic acid, 
4-(N-ethylamino)benzoic acid, 3-(N,N-dimethylamino) benzoic acid, 
4-(N,N-dimethylamino) benzoic acid, and the like. 
Preferred aromatic carboxylic acids include 3-hydroxybenzoic acid, 
4-amino-3-hydroxybenzoic acid, 3-nitrobenzoic acid, 4-nitrobenzoic acid, 
3-hydroxy-4-nitrobenzoic acid, 4-hydroxy-3-nitrobenzoic acid, 
3-aminobenzoic acid, 4-aminobenzoic acid, 3-amino-4-hydroxybenzoic acid, 
and 4-amino-3-hydroxybenzoic acid. 
When the aromatic carboxylic acid contains a hydroxy group, for example, 
when A or R.sub.1 is hydroxy, protection of the aromatic hydroxy groups 
may be accomplished using well-known procedures. The choice of a suitable 
protecting group for a particular hydroxy aromatic carboxylic acid will be 
apparent to those skilled in the art. Various protecting groups, and their 
introduction and removal, are described, for example, in T. W. Greene and 
P. G. M. Wuts, Protective Groups in Organic Synthesis, Second Edition, 
Wiley, New York, 1991, and references cited therein. 
Deprotection of the aromatic hydroxy group(s) can also be accomplished 
using conventional procedures. Appropriate conditions for this 
deprotection step will depend upon the protecting group(s) utilized in the 
synthesis and will be readily apparent to those skilled in the art. For 
example, benzyl protecting groups may be removed by hydrogenolysis under 1 
to about 4 atmospheres of hydrogen in the presence of a catalyst, such as 
palladium on carbon. Typically, this deprotection reaction is conducted in 
an inert solvent, preferably a mixture of ethyl acetate and acetic acid, 
at a temperature of from about 0.degree. C. to about 40.degree. C. for 
about 1 to about 24 hours. 
When synthesizing the polyalkyl and polyalkenyl aromatic amides of formula 
I having an amino group on the aromatic moiety (i.e., where A is an amino 
group), it is generally desirable to first prepare the corresponding nitro 
compound (i.e., where A is a nitro group) and then to reduce the nitro 
group to an amino group using conventional procedures. Aromatic nitro 
groups may be reduced to amino groups using a number of procedures that 
are well known in the art. For example, aromatic nitro groups may be 
reduced under catalytic hydrogenation conditions; or by using a reducing 
metal, such as zinc, tin, iron, and the like, in the presence of an acid, 
such as dilute hydrochloric acid. 
Generally, reduction of the nitro group by catalytic hydrogenation is 
preferred. Typically, this reaction is conducted using about 1 to 4 
atmospheres of hydrogen and a platinum or palladium catalyst, such as 
palladium on carbon. The reaction is typically carried out at a 
temperature of about 0.degree. C. to about 100.degree. C. for about 1 to 
24 hours in an inert solvent, such as ethanol, ethyl acetate, toluene, and 
the like. Hydrogenation of aromatic nitro groups is discussed in further 
detail in, for example, P. N. Rylander, Catalytic Hydrogenation in Organic 
Synthesis, pp. 113-137, Academic Press (1979); and Organic Synthesis, 
Collective Vol. I, Second Edition, pp. 240-241, John Wiley and Sons, Inc. 
(1941); and references cited therein. 
In certain cases where the hydroxy aromatic carboxylic acids have bulky 
alkyl groups adjacent to the hydroxy group, such as 
3,5-di-t-butyl-4-hydroxybenzoic acid, it will generally not be necessary 
to protect the hydroxy group prior to formation of the acyl halide, since 
such hydroxy groups are sufficiently sterically hindered so as to be 
substantially non-reactive with the halide moiety. 
The acyl halide of formula II may then be prepared by reacting the 
protected aromatic carboxylic acid with an inorganic halide, such as 
thionyl chloride, phosphorous trichloride, phosphorous tribromide, or 
phosphorous pentachloride; or with oxalyl chloride, using conventional 
procedures. 
Typically, this reaction will be conducted using about 1 to 5 molar 
equivalents of the inorganic acyl halide or oxalyl chloride, either neat 
or in an inert solvent, such as diethyl ether, at a temperature in the 
range of about 20.degree. C. to about 80.degree. C. for about 1 to about 
48 hours. A catalyst, such as N,N-dimethylformamide, may also be used in 
this reaction. 
B. Preparation of the Polyalkyl or Polyalkenyl Substituted Amine 
The polyalkyl or polyalkenyl substituted amine of formula III comprises the 
reaction product of a polyalkyl or polyalkenyl halide derived from a 
polyolefin having an average molecular weight of about 450 to 5,000 and a 
nitrogen-containing compound selected from ammonia, a primary monoamine 
having from 1 to 6 carbon atoms, and a polyamine having from 2 to 3 
nitrogen atoms and from 2 to carbon atoms. 
As indicated above, the polyalkyl or polyalkenyl substituent on the 
polyalkenyl or polyalkenyl amine will have an average molecular weight in 
the range of about 450 to 5,000, preferably about 500 to 5,000, more 
preferably about 500 to 3,000, and most preferably about 600 to 2,000. 
The polyalkyl or polyalkenyl substituent on the polyalkyl or polyalkenyl 
amine employed in the invention may be generally derived from polyolefins 
which are polymers or copolymers of mono-olefins, particularly 
1-mono-olefins, such as ethylene, propylene, butylene, and the like. 
Preferably, the mono-olefin employed will have 2 to about 24 carbon atoms, 
and more preferably, about 3 to 12 carbon atoms. More preferred 
mono-olefins include propylene, butylene, particularly isobutylene, 
1-octene, and 1-decene. Polyolefins prepared from such mono-olefins 
include polypropylene, polybutene, especially polyisobutene, and the 
polyalphaolefins produced from 1-octene and 1-decene. Most preferred are 
polyolefins prepared from polyisobutene. 
One type of suitable polyolefins are those containing an alkylvinylidene 
isomer present in an amount at least about 20%, and preferably at least 
50% of the total polyolefin composition. The preferred alkylvinylidene 
isomers include methylvinylidene and ethylvinylidene, more preferably the 
methylvinylidene isomer. 
Accordingly, high molecular weight polyolefins which may be used in this 
invention include polyisobutenes which comprise at least about 20% of the 
more reactive methylvinylidene isomer, preferably at least 50%, and more 
preferably at least 70%. Suitable polyisobutenes include those prepared 
using BF.sub.3 catalysts. The preparation of such polyisobutenes in which 
the methylvinylidene isomer comprises a high percentage of the total 
composition is described in U.S. Pat. Nos. 4,152,499 and 4,605,808. 
Examples of suitable polyisobutenes having a high alkylvinylidene content 
include Ultravis 30, a polyisobutene having a molecular weight of about 
1300 and a methylvinylidene content of about 76%, available from British 
Petroleum. 
The amine component of the polyalkyl or polyalkenyl substituted amine may 
be derived from ammonia, a primary monoamine, or a polyamine having 
terminal amino nitrogen atoms. Primary monoamines useful in preparing 
compounds of the present invention contain 1 nitrogen atom and from 1 to 6 
carbon atoms. Examples of suitable monoamines include N-methylamine, 
N-ethylamine, N-n-propylamine, N-isopropylamine, N-n-butylamine, 
N-isobutylamine, N-sec-butylamine, N-tert-butylamine, N-n-pentylamine, and 
N-n-hexylamine. Preferred primary amines are N-methylamine, N-ethylamine, 
and N-n-propylamine. 
When the amine component is derived from a polyamine, the polyamine will be 
either an alkylene diamine or a dialkylene triamine. The alkylene group 
will contain from 2 to 5 carbon atoms, preferably from 2 to 3 carbon 
atoms. Examples of such polyamines include ethylene diamine, propylene 
diamine, isopropylene diamine, butylene diamine, isobutylene diamine, 
pentylene diamine, diethylene triamine, dipropylene triamine, 
diisopropylene triamine, dibutylene triamine, diisobutylene triamine, and 
dipentylene triamine. Preferred polyamines are ethylene diamine and 
diethylene triamine. 
Particularly preferred polyalkyl and polyalkenyl substituted amines include 
polyisobutenyl ethylene diamine and polyisobutyl amine, wherein the 
polyisobutyl group is substantially saturated and the amine moiety is 
derived from ammonia. 
The polyalkyl and polyalkenyl substituted amines employed to make the 
aromatic amides of this invention are prepared by conventional procedures 
known in the art. Such polyalkyl substituted amines and their preparations 
are described in detail in U.S. Pat. Nos. 3,438,757; 3,565,804; 3,574,576; 
3,898,056; 3,960,515; and 4,832,702, the disclosures of which are 
incorporated herein by reference for all purposes. 
C. Preparation of the Polyalkyl or Polyalkenyl Aromatic Amide 
Reaction of the acyl halide of formula II with a polyalkyl or polyalkenyl 
substituted amine of formula III provides a polyalkyl or polyalkenyl 
aromatic amide of formula I. 
Typically, this reaction is conducted by contacting a polyalkyl or 
polyalkenyl substituted amine with about 1.0 to about 3.5 molar 
equivalents of an acyl halide of formula II in an inert solvent, such as 
toluene, dichloromethane, diethyl ether, and the like, at a temperature in 
the range of about 25.degree. C. to about 150.degree. C. The reaction is 
generally complete in about 0.5 to about 48 hours. Preferably, the 
reaction is conducted in the presence of a sufficient amount of an amine 
capable of neutralizing the acid generated during the reaction, such as 
triethylamine, di(isopropyl)ethylamine, pyridine, or 
4-dimethylamino-pyridine. 
Fuel Compositions 
The polyalkyl and polyalkenyl aromatic amides of the present invention are 
useful as additives in hydrocarbon fuels to prevent and control engine 
deposits, particularly intake valve deposits. The proper concentration of 
additive necessary to achieve the desired deposit control varies depending 
upon the type of fuel employed, the type of engine, and the presence of 
other fuel additives. 
In general, the concentration of the polyalkyl and polyalkenyl aromatic 
amides of this invention in hydrocarbon fuel will range from about 50 to 
about 2,500 parts per million (ppm) by weight, preferably from 75 to 1,000 
ppm. 
When other deposit control additives are present, a lesser amount of the 
present additive may be used. 
The polyalkyl and polyalkenyl aromatic amides of the present invention may 
be formulated as a concentrate using an inert stable oleophilic (i.e., 
dissolves in gasoline) organic solvent boiling in the range of about 
150.degree. F. to 400.degree. F. (about 65.degree. C. to 205.degree. C.). 
Preferably, an aliphatic or an aromatic hydrocarbon solvent is used, such 
as benzene, toluene, xylene, or higher-boiling aromatics or aromatic 
thinners. Aliphatic alcohols containing about 3 to 8 carbon atoms, such as 
isopropanol, isobutylcarbinol, n-butanol, and the like, in combination 
with hydrocarbon solvents are also suitable for use with the present 
additives. In the concentrate, the amount of the additive will generally 
range from about 10 to about 70 weight percent, preferably 10 to 50 weight 
percent, more preferably from 20 to 40 weight percent. 
In gasoline fuels, other fuel additives may be employed with the additives 
of the present invention, including, for example, oxygenates, such as 
t-butyl methyl ether, antiknock agents, such as methylcyclopentadienyl 
manganese tricarbonyl, and other dispersants/detergents, such as 
hydrocarbyl amines, hydrocarbyl poly(oxyalkylene) amines, or succinimides. 
Additionally, antioxidants, metal deactivators, and demulsifiers may be 
present. 
In diesel fuels, other well-known additives can be employed, such as pour 
point depressants, flow improvers, cetane improvers, and the like. 
A fuel-soluble, nonvolatile carrier fluid or oil may also be used with the 
polyalkyl and polyalkenyl aromatic amides of this invention. The carrier 
fluid is a chemically inert hydrocarbon-soluble liquid vehicle which 
substantially increases the nonvolatile residue (NVR), or solvent-free 
liquid fraction of the fuel additive composition while not overwhelmingly 
contributing to octane requirement increase. The carrier fluid may be a 
natural or synthetic oil, such as mineral oil, refined petroleum oils, 
synthetic polyalkanes and alkenes, including hydrogenated and 
unhydrogenated polyalphaolefins, and synthetic polyoxyalkylene-derived 
oils, such as those described, for example, in U.S. Pat. No. 4,191,537 to 
Lewis and U.S. Pat. No. 4,877,416 to Campbell, and polyesters, such as 
those described, for example, in U.S. Pat. Nos. 3,756,793 and 5,004,478 to 
Robinson and Vogel et al., respectively, and in European Patent 
Application Nos. 356,726 and 382,159, published Mar. 7, 1990 and Aug. 16, 
1990, respectively. 
These carrier fluids are believed to act as a carrier for the fuel 
additives of the present invention and to assist in removing and retarding 
deposits. The carrier fluid may also exhibit synergistic deposit control 
properties when used in combination with a polyalkyl or polyalkenyl 
aromatic compound of this invention. 
The carrier fluids are typically employed in amounts ranging from about 100 
to about 5,000 ppm by weight of the hydrocarbon fuel, preferably from 400 
to 3,000 ppm of the fuel. Preferably, the ratio of carrier fluid to 
deposit control additive will range from about 0.5:1 to about 10:1, more 
preferably from 1:1 to 4:1, most preferably about 2:1. 
When employed in a fuel concentrate, carrier fluids will generally be 
present in amounts ranging from about 20 to about 60 weight percent, 
preferably from 30 to 50 weight percent. 
EXAMPLES 
The following examples are presented to illustrate specific embodiments of 
the present invention and synthetic preparations thereof; and should not 
be interpreted as limitations upon the scope of the invention. 
EXAMPLE 1 
Preparation of 4-Benzyloxybenzoyl chloride 
To a flask equipped with a magnetic stirrer and drying tube was added 
4-benzyloxybenzoic acid (30.0 grams), anhydrous dichloromethane (200 mL), 
and then oxalyl chloride (28.7 mL). The resulting mixture was stirred at 
room temperature for 16 hours and the solvent removed in vacuo to yield 
43.2 grams of the desired acid chloride as a white solid. 
EXAMPLE 2 
Preparation of Bis-N,N'-4-Benzyloxybenzamide of 
Polyisobutenylethylenediamine 
##STR11## 
Polyisobutenylethylenediamine having an average of 23 isobutyl units 
(prepared essentially as described in Example 3 of U.S. Pat. No. 
3,960,515) was chromatographed on silica gel eluting with hexane/diethyl 
ether (1:1) followed by hexane/diethyl ether/methanol/isopropylamine 
(40:40:15:5). 4-Benzyloxybenzoyl chloride (73.7 grams, prepared as in 
Example 1) was combined with 193.2 grams of chromatographed 
polyisobutenylethylenediamine and anhydrous toluene (2 liters). 
Triethylamine (43.6 mL) and 4-dimethylamino pyridine (8.7 grams) were then 
added and the resulting mixture was heated to reflux under nitrogen for 16 
hours. The reaction was cooled to room temperature and diluted with 3 
liters of hexane. The organic layer was washed twice with saturated 
aqueous sodium bicarbonate solution and once with brine. The organic layer 
was dried over anhydrous magnesium sulfate, filtered, and the solvents 
removed in vacuo to yield 264.4 grams of a black oil. The oil was 
chromatographed on silica gel, eluting with hexane/diethyl 
ether/isopropylamine (49:49:2) to afford 155.0 grams of the desired 
product as a brown oil. 
EXAMPLE 3 
Preparation of Bis-N,N'-4-Hydroxybenzamide of Polyisobutylethylenediamine 
##STR12## 
A solution of 155.0 grams of the product from Example 2 in 300 mL of ethyl 
acetate, 300 mL of acetic acid and 100 mL of toluene containing 15.0 grams 
of 10% palladium on charcoal was hydrogenolyzed at 35-40 psi for 16 hours 
on a Parr low-pressure hydrogenator. Catalyst filtration and removal of 
the residual acetic acid with toluene in vacuo yielded 138.8 grams of the 
desired product as a brown oil. R (neat) 1609 cm.sup.-1 ; .sup.1 H NMR 
(CDCl.sub.3, D.sub.2 O) .delta.7.5-7.7 (m, 4H), 6.5-6.8 (m, 4H), 3.6-4.2 
(m, 6H), 0.6-1.6 (m, 183H). 
EXAMPLE 4 
Preparation of Bis-N,N'-4-Nitrobenzamide of Polyisobutenylethylenediamine 
##STR13## 
Polyisobutenylethylenediamine having an average of 23 isobutyl units 
(prepared essentially as described in Example 3 of U.S. Pat. No. 
3,960,515) was chromatographed on silica gel eluting with hexane/diethyl 
ether (1:1) followed by hexane/diethyl ether/methanol/isopropylamine 
(40:40:15:5). 4-Nitrobenzoyl chloride (5.7 grams) was combined with 20.0 
grams of chromatographed polyisobutenylethylenediamine and anhydrous 
toluene (200 mL). Triethylamine (5.1 mL) was added and the resulting 
mixture was heated to reflux under nitrogen for 16 hours. The reaction was 
cooled to room temperature and diluted with 600 mL of hexane. The organic 
layer was washed twice with saturated aqueous sodium bicarbonate solution 
and once with brine. The organic layer was dried over anhydrous magnesium 
sulfate, filtered and the solvents removed in vacuo to yield 23.7 grams of 
the desired product as a brown oil. .sup.1 H NMR (CDCl.sub.3, D.sub.2 O) 
.delta.8.1-8.35 (m, 8H), 5.4-5.6 (m, 1H), 3.5-4.2 (m, 6H), 0.6-1.8 (m, 
180H). 
EXAMPLE 5 
Preparation of Bis-N,N'-4-Aminobenzamide of Polyisobutylethylenediamine 
##STR14## 
A solution of 18.7 grams of the product from Example 4 in 200 mL of ethyl 
acetate and 50 mL of toluene containing 4.0 grams of 10% palladium on 
charcoal was hydrogenated at 35-40 psi for 16 hours on a Parr low-pressure 
hydrogenator. Catalyst filtration and removal of the residual acetic acid 
with toluene in vacuo yielded 15.4 grams of the desired product as a brown 
oil. .sup.1 H NMR (CDCl.sub.3, D.sub.2 O) .delta.7.4-7.7 (m, 4H), 6.5-6.8 
(m,4H), 3.4-4.0 (m, 6H), 0.6-1.6 (m, 183H). 
EXAMPLE 6 
Single-Cylinder Engine Test 
The test compounds were blended in gasoline and their deposit reducing 
capacity determined in an ASTM/CFR single-cylinder engine test. 
A Waukesha CFR single-cylinder engine was used. Each run was carried out 
for 15 hours, at the end of which time the intake valve was removed, 
washed with hexane, and weighed. The previously determined weight of the 
clean valve was subtracted from the weight of the value at the end of the 
run. The difference between the two weights is the weight of the deposit. 
A lesser amount of deposit indicates a superior additive. The operating 
conditions of the test were as follows: water jacket temperature 
200.degree. F.; vacuum of 12 in Hg, air-fuel ratio of 12, ignition spark 
timing of 40.degree. BTC; engine speed is 1,800 rpm; the crankcase oil is 
a commercial 30W oil. 
The amount of carbonaceous deposit in milligrams on the intake valves is 
reported for each of the test compounds in Table I. 
TABLE I 
______________________________________ 
Intake Valve Deposit Weight 
(in milligrams) 
Sample.sup.1 
Run 1 Run 2 Average 
______________________________________ 
Base Fuel 302.6 312.2 307.4 
Example 3 5.7 7.2 6.5 
Example 4 112.1 127.4 118.3 
Example 5 265.1 260.1 262.6 
______________________________________ 
.sup.1 At 200 parts per million actives (ppma). 
The base fuel employed in the above single-cylinder engine tests was a 
regular octane unleaded gasoline containing no fuel detergent. The test 
compounds were admixed with the base fuel to give a concentration of 200 
ppma (parts per million actives). 
The data in Table I illustrates the significant reduction in intake valve 
deposits provided by the polyalkyl and polyalkenyl aromatic amides of the 
present invention (Examples 3, 4, and 5) compared to the base fuel.