EP0448602A1

EP0448602A1 - Method for functionalization of nucleophiles

Info

Publication number: EP0448602A1
Application number: EP90900580A
Authority: EP
Inventors: Jonathan Stewart Witzeman; William Dell Nottingham
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1988-12-12
Filing date: 1989-12-12
Publication date: 1991-10-02
Also published as: CA2004700A1; DE68905787D1; ATE87608T1; EP0376859A1; KR0152527B1; KR0153750B1; WO1990006911A1; KR910700224A; EP0376859B1; JP2763676B2; JPH04502313A; ES2039922T3; DE68905787T2

Abstract

Process for the preparation of acetoacetates and other beta -ketoesters is provided, involving reaction of nitrogen, oxygen or sulfur nucleophiles with a tertiaryalkyl acetoacetate or tertiaryalkyl beta -ketoester.

Description

Method for Functionalization of Nucleophiles

This invention relates to the functionalization of nucleophiles with β-dicarbonyl compounds. In one aspect, this invention relates to the acetoacetylation of nucleophiles. In another aspect, this invention relates to the acetoacetylation of low molecular weight nucleophiles. In yet another aspect, this invention relates to the acetoacetylation of polymeric nucleophiles.

Background

The acetoacetate moiety has been used in the coatings industry to impart functionality capable of undergoing a variety of cross-linking reaction while simultaneously lowering the viscosity of the resulting formulation. Among the reactions which can be used to promote cross-linking of acetoacetylated polymeric materials are reactions with activated olefins (commonly referred to as the Michael

reaction), diamines, melamine, isocyanates, and the like. Coatings prepared from acetoacetylated

polymers using such cross-linking strategies often exhibit improved stain-resistance, sal t-spray

resistance and better adhesion to the metal surface when compared to coatings prepared from nonacetoacetylated polymer.

Interest in the use of acetoacetylated materials in coatings has led to the need for general synthetic procedures for the preparation of acetoacetylated compounds which can be readily practiced on

industrial scale. It is known that acetoacetylated acrylic resins can be prepared by the copolymerization of acetoacetoxyethyl methacrylate with acrylic or methacrylic monomers. Alternatively, acetoacetylated polymers or resins can be prepared by the acetoacetylation of the polymeric substrate, rather than by polymerization of acetoacetylated monomers. One substrate for which this method of synthesis is generally required is in the preparation of acetoacetylated polyester resins.

Simple acetoacetylated materials can be prepared in a variety of ways. For example, an appropriate nucleophile can be treated with diketene.

Alternatively, such nucleophile can be subjected to a thermal reaction with 2,2,6-trimethyl-4H-1,3-dioxin-A-one (TKD, the diketene-acetone adduct). As yet another alternative, such nucleophile can be

subjected to transesterification with another

acetoacetate moiety (referred to hereinafter as

"transacetoacetylation").

The industrial-scale use of diketene for such applications is impractical due to strict governmental regulations regarding the shipping of this material. In addition, the classification of

diketene as a lachrymator make the large scale use of this material undesirable. The dioxinone, TKD, while effective for acetoacetylation, is currently too costly a raw material to be employed for large scale industrial applications.

While transesterification reactions are well known in the preparation of polyester coating resins, transesterification of acetoacetates (i.e., transacetoacetylation) has not found wide spread application. One published procedure for the preparation of acetoacetic acid derivatives involves heating solutions of a higher boiling alcohol with an excess Of methyl or ethyl acetoacetate while thέ volatile methyl or ethyl alcohol co-product is removed by distillation. Reaction times for such procedure are on the order of many hours when carried out at elevated temperatures (about 100°C). Another method for transacetoacetylation which has been suggested in the art involves contacting the alcohol of interest with a large excess of methylacetoacetate and a

4-dimethylaminopyridine catalyst in a high boiling hydrocarbon solvent such as toluene for an extended period of time. An alternate method for transacetoacetylation disclosed in the art is the use of titanium catalysts.

Yet another prior art disclosure of transesterification reactions employing acetoacetic moieties is found in European Patent Application 227, 454, assigned to Cook Paint and Varnish Inc. The reaction between a polyhydroxy functional monomer or polymer and an alkyl monofunctional acetoacetate is disclosed. Suitable acetoacetate esters are

disclosed to be methyl acetoacetate, ethyl acetoacetate, isopropyl acetoacetate, butyl acetoacetate, t-butyl acetoacetate, methyl benzyl acetoacetate and dodecyl acetoacetate. The examples in this disclosure demonstrate only the use of ethyl acetoacetate. There is no suggestion in the reference of any benefit from using one acetoacetate moiety rather than another taken from the above list of "suitable" compounds.

The high dilution, large amounts of catalyst used and long reaction times involved make each of the prior art procedures for transacetoacetylation impractical, especially when application on a

commercial scale is contemplated. Prior art

procedures are particularly ill-suited for the acetoacetylation of higher molecular weight

(including polymeric) nucleophiles. There is, therefore, a need in the art for simplified procedure for transacetoacetylation, which procedure does not require extreme reaction conditions or large

quantities of unreactive materials.

Statement of the Invention

In accordance with the present invention, we have discovered that a variety of nucleophiles can be functionalized by contacting such nucleophiles with a specifically defined β-dicarbonyl compound, i.e., a g-ketoester as defined below under moderate

reaction conditions of time and temperature.

The invention functionalization process is relatively rapid, can be carried out in the

substantial absence of catalysts and/or solvent, avoids the use of toxic and/or more expensive

starting materials, is of very general applicability, provides products with low level of residual color, and produces volatile and readily recoverable coproducts.

Detailed Description of the Invention

In accordance with the present invention, there is provided a method for the functionalization of nucleophiles having the structural formula:

HY-R_x wherein Y is selected from nitrogen, oxygen or sulfur;

wherein R is selected from the group consisting of: C₁ up to C₁₂ hydrocarbyl radical substituted with 0 up to 3 hydroxyl units, formyl units, nitro units, chlorine atoms, bromine atoms, ester moieties of the structure:

wherein Z is a hydrocarbyl moiety having in the range of 1 up to 6 carbon atoms,, or alkoxy moieties of the structure, -OZ, wherein Z is as defined above; and wherein R can also be H when Y is N; and

wherein x is 1 when Y is 0 or S, and x is 2 when Y is N;

said process comprising contacting said nucleophile with a β-ketoester compound having the

structure;

wherein

R' Is a C₁ up to C₈ alkyl, aryl or halide substituted alkyl or aryl moiety,

each R" is independently selected from H, a C₁ up to C₈ alkyl moiety, or a halogen, and

R''' is selected from H, C₁ up to C₄ alkyl moieties, C₄ up to C₁₀ aromatic, heteroaromatic and substituted aromatic moieties, or halogens;

wherein said contacting is carried out at a temperature and for a time sufficient to produce the desired product.

In accordance with an alternate embodiment of the present invention, there is provided a method for the functionalization of nucleophiles having the structural formula: HY-R_x wherein Y is selected from nitrogen, oxygen or sulfur;

wherein R is selected from:

i) hydroxylated polyesters having a number average molecular weight in the range of about 500 up to 10,000, or

ii) acrylic polymers containing free hydroxyl groups and having a number average molecular weight in the range of about 500 up to 10,000; and wherein R can also be H when Y is N; and

wherein x is 1 when Y is 0 or S, and x is 2 wheren Y is N;

said process comprising contacting said nucleophile with a compound having the structure:

wherein

R' is a C₁ up to C₈ alkyl, aryl or halide substituted alkyl or aryl moiety,

each R" is independently selected from H, a C₁ to C₈ alkyl moiety, or a halogen, and

Nucleophiles contemplated for the use in the practice of the present invention include, inter alia, alkanols, alkylamines, alkylthiols, aryl alcohols, aryl amines and arylthiols. Alkyl moieties having in the range of 1 up to 12 carbon atoms are contemplated, while aryl moieties having in the range of 4 up to 12 carbon atoms are contemplated.

Exemplary nucleophiles of this type include

n-butanol, octanol, butyl amine, dibutyl amine, aniline, phenol, thiophenol, benzyl alcohol,

nitroaniline, 1-methyl-1-cyclohexanol, and the like.

Additional nucleophiles contemplated for use in the practice of the present invention include allyl alcohols having the structure:

CR⁴2=CR⁴-CR⁴a-OH wherein each R⁴ is independently selected from the group consisting of hydrogen and hydrocarbyl radicals having 1 up to 4 carbon atoms. Exemplary nucleophiles of this type include allyl alcohol, 3-methyl-2-buten-1-ol, 2-methyl-2-propen-1-ol, 3-methyl-3-buten-2-ol, and the like.

Acrylates having the structure:

are also contemplated for use in the practice of the present invention. Each R⁵ is independently

selected from hydrogen, methyl or ethyl radicals, and n can vary from 1 up to 6. Exemplary acrylate moieties satisfying this structure include hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxybutyl methacrylate, hydroxybutyl acrylate, and the like.

Polyol nucleophiles contemplated for use in the practice of the present invention have the general structure: HO-(CR⁶ ₂ )_m-OH wherein each R⁶ is independently selected from the group consisting of hydrogen, hydroxy, and alkylene radicals having 1 up to 4 carbon atoms, while m can vary from 2 up to about 12.

Polymeric nucleophiles contemplated for use in the practice of the present invention include

i) hydroxylated polyesters having a number average molecular weight in the range of about 500 up to 10,000 or

(ii) acrylic polymers containing free hydroxyl groups and having a number average molecular weight in the range of about 500 up to 10,000.

Preferred hydroxylated polyesters have the structure:

wherein

each R⁷ and R^7' is independently selected from H, C₁ up to C₄ alkyl, hydroxy, or alkoxy of the structure, -OZ, wherein Z is a hydrocarbyl moiety having in the range of 1 up to 6 carbon atoms; and each R⁸ and R^8' is independently selected from 1,2-arylene, 1,3-arylene, 1,4-arylene or an alkylene moiety of the structure:

-(CR⁹ ₂)_d- wherein each R⁹ is independently selected from H,

C₁ up to C₄ alkyl, hydroxy or alkoxy of the

structure -OZ, wherein Z is a hydrocarbyl moiety having in the range of 1 up to 6 carbon atoms, and d is a whole number which can vary from 0 up to 24; a can vary from 1 up to 20;

b can vary from 2 up to 12; and

c can vary from 2 up to 12.

Exemplary materials which conform to this generic formula include hydroxylated polyesters having a number average molecular weight in the range of about 500 up to 6000 and comprising at least one

dicarboxylic moiety selected from the group

consisting of: phthalic acid,

terephthalic acid,

isophthalic acid

adipic acid,

1,4-cyclohexane dicarboxylic acid,

1,3-cyclohexane dicarboxylic acid,

1,2-cyclohexane dicarboxylic acid,

and esters thereof; and at least one polyol selected from the group

consisting of: ethylene glycol,

propylene glycol,

pentaerythritol,

neopentylglycol,

2,2,4-trimethy1-1,3-pentanediol,

glycerol,

1,1,1-trimethylolpropane, and

1,1,1-trimethylolethane. Preferred acrylic polymers employed in the practice of the present invention are polymers prepared from hydroxyethyl methacrylate, hydroxyethyl acrylate, 4-hydroxybutyl acrylate and/or 4-hydroxybutyl methacrylate with at least one comonomer selected from the group consisting of: methyl acrylate,

ethyl acrylate,

propyl acrylate,

butyl acrylate,

methyl methacrylate,

ethyl methacrylate,

propyl methacrylate, and

butyl methacrylate. β-Ketoester compounds contemplated for use in the practice of the present invention are compounds having the structure:

wherein

R' is a C₁ up to C₈ alkyl aryl or halide substituted alkyl or aryl moiety,

R''' is selected from H, C₁ up to C₄ alkyl moieties, C₄ up to C₁₀ aromatic, heteroaromatic and substituted aromatic moieties, or halogens.

Preferred β-ketoesters useful in the practice of the present invention include compounds wherein is methyl or tertiary butyl, R" is H or a C₁ up to C₄ alkyl moiety and R''' is H, a C₁ up to C₄

alkyl moiety or a chloride radical.

Presently, most preferred β-ketoester moieties for use in the practice of the present invention include t-butyl acetoacetate, 2-chloro-t-butyl acetoacetate, t-butyl pivaloyl acetate, and t-amyl acetoacetate. Presently most preferred acetoacetates are t-butyl acetoacetate and t-butyl pivaloyl

acetate, because of the ready availability and high reactivity of these compounds.

When t-butyl pivaloyl acetate is employed as the acetoacetylating moiety, a particularly preferred nucelophile to employ in the practice of the present invention is 2-chloro-4-nitroaniline. This combination of reagents gives much more rapid reaction to produce the desired product than does the reaction of 2-chloro-4-nitroaniline with methyl pivaloyl

acetate.

The invention reaction can be carried out under a wide variety of conditions. For example, reaction can be carried out in the presence or absence of solvent. When employed, suitable solvents include aromatic hydrocarbons (e.g., toluene, xylene, and the like) esters, e.g., butyl acetate, ethyl amyl

acetate, ethyl-3-ethoxy propionate, and the like), ketones (e.g., methyl isobutyl ketone, methyl amyl ketone, methyl isoamyl ketone, ethyl butyl ketone, and the like), as well as any of the above solvents used in conjunction with a material capable of azeotroping with t-butanol (e.g., cyclohexane).

When solvent is employed, concentrations of

β-ketoester of from about 0.1 up to 10 moles per liter can be employed, depending on the solubility of the nucleophile to be employed. The invention process can be carried out at a wide range of temperatures. Typical temperatures fall in the range of about 80 up to 200ºC, with temperatures in the range of about 90 up to 160°C being preferred.

Reaction times in the range of about 0.5 up to 24 hours are generally suitable. Preferably,

reaction times in the range of about 0.5 up to 8 hours are employed. Those of skill in the art recognize that the desired reaction time will vary as a function of numerous variables, such as, for example, reaction temperature, the desired degree of conversion, the particular reactants employed, and so on.

The use of transesterification catalysts in the practice of the present invention is optional.

Generally, little benefit is observed due to the presence of catalysts. It is presently preferred to conduct the present invention in the absence of added catalysts. When employed, however, catalyst

concentrations up to about 5 weight percent are acceptable, with quantities of catalyst less than about 11 by weight being preferred. When employed, catalysts typically employed for transesterification reactions are contemplated. A wide variety of such catalysts can be readily identified by those of skill in the art.

The invention will now be described in greater detail by reference to the following nonlimiting examples.

EXAMPLE 1

Several methods for functionalization of

nucleophiles in accordance with the present invention are illustrated below. Method A

The preparation of the bis-acetoacetate of neopentyl glycol (NPG) is illustrative of this procedure. In a 125 mL Erlenmeyer flask with

magnetic stirrer and thermometer was placed 10.03 g NPG (0.096 mole), 32.1 g tertiary butyl acetoacetate (tBAA; 0.203 mol) and 32 mL xylene. The solution was heated with stirring on a hot plate to the boiling point of xylene. Once the solution reached 138°C (ca. 10 min) the solution was removed from the hot plate, cooled to room temperature, concentrated in vacuo and short-path distilled to yield 22.83 g

(87.11) bis-acetoacetate b.p. 145-148°C (0.05 mm Hg).

Method B

Another procedure involved heating the alcohol and tBAA, (or beta-ketoester) in solvent, in a round-bottom flask with magnetic stirrer, 5-plate Oldershaw column and still head for removal of the t-butanol co-product. For example: a solution of n-octanol (13 g, 0.1 mol), tBAA (16.6 g, 0.105 mol) and 50 mL toluene was heated at reflux until the theoretical amount of t-butyl alcohol was obtained (ca. 15 min. after reflux). The reaction mixture was subsequently concentrated and distilled to give

17.8 g (83.2%) octyl acetoacetate b.p. 95-110°C

(1.0 mm Hg).

Method C

This method is a modification of Method B. In a 300 mL, 3-neck flask with magnetic stirrer, 5-plate Oldershaw column with still head and thermometers in the base and head of the system, was placed 33.52 g tBAA, 30.1 g phenol, 110 mL xylene and 100 mL cyclohexane. The solution was heated to reflux and the t-BuOH/cyclohexane azeotrope removed by distillation. Additional cyclohexane can be added to the reaction if necessary. Total yield of phenyl acetoacetate from this process was 21.9 g (741).

Examples of acetoacetylated materials prepared by methods A-C are given in Table 1. Examples of other beta-ketoesters prepared by method B are given in Table 2.

Table 1

Yield of Various Acetoacetylated Materials

Using t-Butyl Acetoacetate (tBAA)

mL Yield Experimental^a

Nucleophile^b grams g(tBAA) Solvent (%) Method

TMP 47.5 171.00 100 90^d B

TMPD 10.1 22.4 30 87^c A

NPG 10.0 32.1 32 87^c A

NPG 159.2 491.3 450 81^c B

HEMA^g 16.8 20.5 65 70 B

CHDM 9.8 22.1 28 69^c,e A

HNBU₂ 7.65 9.24 25 96 A

PhOH 34 A

30.1 33.5 110/100^f 74 C

Ph-NH₂ 10.0 17.2 25 83 A nBuOH 10.0 21.4 40 87 A n-OctOH 13.0 16.6 50 83 B

Ph-CH₂OH 10.8 16.6 50 89 B

Ester diol 204 10.2 16.2 60 88^c B ρ(NO₂)PhNH₂ 13.8 16.2 50 86 B

1-Me-Cyclohexan -1-ol 11.4 16.2 50 83 B

3-Me-2-buten-1-ol 8.6 16.2 50 97 B

Table 1 (Cont'd.)

(a) Refers to the description of the experimental method set forth in Example 1.

(b) Abbreviations used:

TMPD = 2,2,4-trimethyl-1,3-pentanediol

TMP = trimethylolpropane

NPG = neopentyl glycol or 2,2-dimethyl-1,3-propanediol

HEMA = hydroxyethyl methacrylate

CHDM = cyclohexane-1,4-dimethanol

HNBu₂ = dibutyl amine

Ester diol 204 (sold by Union Carbide). Also known as HPHP — hydroxy pivaloyl hydroxy pivaloate

(c) Yield of bis-acetoacetate for TMPD, NPG, CHDM and Ester diol 204.

(d) Yield of tris-acetoacetate for TMP.

(e) Yield of crystalline material, some cis isomer lost in

recrystallization.

(f) 110 mL xylene, 100 mL cyclohexane.

(g) Reaction also contained 67 mg benzoquinone and 137 mg BHT.

The results presented in Tables 1 and 2

demonstrate the generality of the invention process for the preparation of a wide variety of low

molecular weight acetoacetate moieites. The

generality of the invention process for polymeric nucleophiles is demonstrated in Examples 3 and 4.

EXAMPLE 2

The following procedure was used to determine the relative rates of reaction of various

nucleophiles with the beta-ketoesters. A solution of 4.7-5.4 mmol acetoacetate (ketoester), nucleophile (4.9-50 mmol) and p-dichlorobenzene internal standard (450-500 mg) diluted to 10 mL with p-xylene was placed in a flask with condenser and N₂ inlet. The apparatus was placed in a constant temperature bath, samples periodically withdrawn and the extent of reaction assessed by gas chromatography. Rate data obtained by this method are given in Tables 3 and 4. In addition, the advantages of the invention process for the reaction of t-butyl pivaloyl acetate with 2-chloro-4-nitroaniline are shown in Table 5.

Table 3

Rate Constants for Reactions of QOAcAc

With n-BuOH at 91.85°C Q k x 10^4a [nBuOH]^b [QOAcAc]^c tBu 1.716 0.492 0.474 tBu 1.662 2.623 0.475 tBu^d 1.859 1.027 0.472 tBu 1.559 0.174 0.068

Et 0.102 0.526 0.473

Et 0.136 4.987 0.477

Me 0.097 0.611 0.551 iBu 0.138 1.068 0.474 iPr 0.140 1.070 0.537

HC(iPr)₂ 0.083 1.046 0 .477 tAm 1.460 1.072 0.495

TKD 1.07

a. First-order rate constant in sec^-1.

b. Molar concentration of n-BuOH.

c. Molar concentration of acetoacetate.

d. Acetoacetate distilled prior to use.

Table 4

First-Order Rate Constants (In Sec^-1) For Reaction of Various Beta-Ketoesters With Nucleophiles

A. Rate of Reaction of 2-Chloro Acetoacetates with n-Octanol at 114.9ºC

Acetoacetate [AcAc] [n-OctOH] k₁x10⁶ t-Butyl 0.48 0.72 8.55 t-Butyl 0.48 2.88 8.62

Ethyl 0.48 2.88 2.93 B. Rate of Reaction of 2-Methyl Acetoacetates with n-Octanol at 114.9°C

Acetoacetate [AcAc] [n-OctOH] k₁x10⁶ t-Butyl 0.48 0.72 24.3 t-Butyl 0.48 2.88 29.7 Ethyl 0.48 2.88 3.7

C. Rate of Reaction of 4-Chloro Acetoacetates with n-Octanol at 91.9°C

Acetoacetate [AcAc] [n-OctOH] k₁x10⁴ t-Butyl 0.48 2.88 3.00 t-Butyl 0.48 0.72 2.78

Ethyl 0.48 0.72 0.21

Ethyl 0.48 2.88 0.27

D. Rate of Reaction of Pivaloyl Acetates with

n-BuOH at 91.9°C

Ester k₁x10⁴

t-Bu 1.54

Me 0.13

The rate data presented in Tables 3 and 4 demonstrate the advantage of the invention process relative to prior art processes employing methyl or ethyl acetoacetate. Rate enhancements of an order of magnitude and higher are routinely observed for the invention process relative to prior art processes.

The percent conversion results summarized in Table 5 demonstrate that t-butyl pivaloyl acetate gives much higher yields of desired product than does methyl pivaloyl acetate. At all time points

analyzed, the yield of product formed from t-butyl pivaloyl acetate is more than double the yield of product obtained from methyl pivaloyl acetate.

EXAMPLE 3 - Acetoacetylation of Polyester Resins

Run No. 1

To a solution of 450.3 g of polyester resin comprised of 44.2% neopentyl glycol (NPG), 3.0% trimethylolpropane (TMP), 28.9% dimethylcyclohexane dicarboxylate (DMCD), 23.9% isophthalic acid with molecular weight of 858-1297 and a hydroxyl number of about 210 in xylene solvent (85% solids) at 140°C was added 120.0 g tBAA. The t-butyl alcohol begin to distill from the reaction immediately and the process was complete in 2 hours. When an identical polyester solution was treated with either ethyl or methyl acetoacetate, the rate of acetoacetylation (as noted by the evolution of alcohol) was 2-6 hours slower, even if 0.1 wt % of a dibutyltin oxide catalyst was used. Analysis of the resultant polyesters by proton nuclear magnetic resonance spectroscopy (¹H-NMR) showed that the polyesters acetoacetylated with methyl acetoacetate (MAA) or ethyl acetoacetate (EAA) and catalyst had been reduced in molecular weight, while no such polyester breakdown was noted for the reaction with tBAA. Run No. 2

In another experiment 102.35 g of a high-solids polyester coating resin comprised of 2,2,4-trimethyl-1,3-propanediol (TMPD; 54 wt %), TMP (4.7 %),

isophthalic acid (22 %) and adipic acid (19.3 %) with a hydroxyl number of about 170 and molecular weight 900-1100 was placed in 500 mL 3-neck flask with addition funnel, 5-plate Oldershaw column with still head and thermometers in the base and head. The resin was diluted to 69% solids with xylene, heated to 120°C, 25.15 g of tBAA were added and the

resultant t-butanol was removed by distillation over a 2 hr. period to obtain an acetoacetylated resin in which 50% of the hydroxyl end groups were acetoacetylated. The ratio of tBAA to polyester could be altered to produce material with 11%, 18%, 25% or 85% acetoacetylation. Run No. 3

In another experiment 392.8 g of a high-solids coating resin comprised of 35.3 wt % isophthalic acid and 64.7 wt % TMPD with a hydroxyl number of about 285-265 and molecular weight 600-800 was placed in a 3-neck flask with addition funnel, mechanical

stirrer, steam-heated reflux column topped with a Dean-Stark trap with condenser. The neat resin was heated to 150ºC and 272.1 g tBAA was added drop-wise over a period of 1.5 hr. Two hours after the

addition was begun 94 % of the theoretical amount of t-butyl alcohol was obtained. Analysis of the resulting resin by ¹H-NMR spectroscopy again

indicated the production of an acetoacetylated resin with 89% of the hydroxyls acetoacetylated.

Run No. 4

In a 250 mL round bottom flask with 6" Vigreaux column, still head, magnetic stirrer and N₂ inlet was placed 25.48 g of a polyester comprised of NPG and terephthalic acid with a hydroxyl number of about 45 and number average molecular weight of about 3089, 1.92 g tBAA and 35 mL n-butyl number average

acetate. The solution was warmed to reflux and solvent removed until the head temperature reached 110°C (approximately 45 minutes). NMR spectroscopic analysis of the resulting concentrated solution showed that approximately 60% of the end groups had been acetoacetylated.

The above runs demonstrate that the Invention process can be used for the acetoacetylation of a variety of hydroxylated polyester resins. The degree of acetoacetylation is readily controlled by varying the t-butyl acetoacetate/polyester ratio. EXAMPLE 4 — Acetoacetylation of Acrylic Resins

Run No. 1

In a 2L 3-neck flask with magnetic stirrer, 5-plate Oldershaw column with still head and nitrogen inlet was placed 517.4 g of an acrylic polymer with acid number 10.6, and hydroxyl number of about 169, in butyl acetate as a 61.3 % solid solution. A

112.8 g sample of tBAA was placed in the flask and the solution was heated to reflux with removal of t-butanol over a period of 50 min. The resulting acetoacetylated polymer was identical by NMR

spectroscopy with one prepared by reaction of the polymer with diketene (ca. 50% acetoacetylation). An identical material was also obtained if the reaction was carried out on the polymer in methyl isobutyl ketone solvent.

Run No. 2

In another experiment 157 g of a 60% solids solution in ethoxyethylpropionate (EEP) of an acrylic terpolymer prepared from 48 wt % of methylmethacrylate, 29 wt % butyl methacrylate and 22 wt % hydroxyethyl methacrylate was acetoacetylated with 12.8 g t-butyl acetoacetate (tBAA) by heating the solution to 160°C and removing the resulting

t-bύtanol by distillation through a 5-plate Oldershaw column. This produced a material in which

approximately 50% of the available hydroxyIs had been acetoacetylated. This same resin was acetoacetylated so as to acetoacetylate about 85% of the available hydroxyls by using 188 g of the resin solution and 26.0 g tBAA. Run No. 3

Using the same method as described in Example 8, 155 g of a 60% solids solution in EEP'of an acrylic copolymer prepared from 70 mol % methyl methacrylate and 30 mol % hydroxyethyl methacrylate was acetoacetylated with 21.76 g tBAA to produce a polymer in which approximately 50% of the hydroxyls had been acetoacetylated. This same polymer was acetoacetylated so as to acetoacetylate about 85% of the hydroxyls by treating 166.7 g of the resin solution with 36.9 g tBAA.

The above runs demonstrate that the invention process can be used for the acetoacetylation of hydroxylated acrylic resins. As was the case with hydroxylated polyesters as reactive nucleophiles, it is possible to control the degree of acetoacetylation by varying the t-butyl acetoacetate/acrylic resin ratio.

The invention has been described in detail with particular reference to preferred embodiments

thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

Claims

Claims We Claim:

1. Method for the functionalization of nucleophiles having the structural formula:

HY-R_x. wherein Y is selected from nitrogen, oxygen or sulfur; wherein R is selected from the group consisting of: C₁ up to C₁₂ hydrocarbyl radical substituted with 0 up to 3 hydroxyl units, formyl units, nitro units, chlorine atoms, bromine atoms, ester moieties of the structure:

wherein Z is a hydrocarbyl moiety having in the range of 1 up to 6 carbon atoms, or alkoxy moieties of the structure, -OZ, wherein Z is as defined above; and wherein R can also be H when Y is N; and wherein x is 1 when Y is 0 or S, and x is 2 when Y is N; said process comprising contacting said

nucleophile with a compound having the

structure:

wherein

R' is a C₁ up to C₈ alkyl, aryl or halide substituted alkyl or aryl moiety, each R" is independently selected from H, a C₁ up to C₈ alkyl moiety, or a halogen, and

R''' is selected from H, C₁ up to C₄ alkyl moieties, C₄ up to C₁₀ aromatic, heteroaromatic and substituted aromatic moieties, or halogens; wherein said contacting is carried out at a temperature and for a time sufficient to produce the desired product.

2. A method in accordance with Claim 1 wherein said nucleophile is selected from alkanols, alkylamines, or alkylthiols having in the range of 1 up to 12 carbon atoms, and substituted

derivatives thereof.

3. A method in accordance with Claim 1 wherein said nucleophile is selected from aryl alcohols, arylamines, or arylthiols having in the range of 4 up to 12 carbon atoms, and substituted

derivatives thereof.

4. A method in accordance with Claim 1 wherein said nucleophile is selected from the group consisting of allyl alcohols having the

structure:

CR⁴ ₂=CR⁴-CR⁴a-OH wherein each R⁴ is independently selected from the group consisting of H and C₁ up to C₄ hydrocarbyl radicals.

5. A method in accordance with Claim 1 wherein said nucleophile is selected from the group

consisting of acrylates having the structure: wherein each R⁵ is independently selected from the group consisting of H, methyl and ethyl radicals, and n can vary from 1 up to 6.

6. A method in accordance with Claim 1 wherein said nucleophile is selected from the group

consisting of poly-ols having the structure:

HO-(CR⁶ ₂)_m-OH wherein each R⁶ is independently selected from the group consisting of H, OH, and C₁ up to C₄ alkylene radicals, and m can vary from 2 up to about 12.

7. A method in accordance with Claim 1 wherein said acetoacetate is selected from the group consisting of t-butyl acetoacetate, 2-chloro-tbutylacetoacetate, t-butyl pivaloyl acetate, and t-amyl acetoacetate.

8. A method in accordance with Claim 1 wherein said acetoacetate is t-butyl acetoacetate.

9. A method in accordance with Claim 1 wherein said acetoacetate is t-butyl pivaloyl acetate.

10. A method in accordance with Claim 9 wherein said nucleophile is 2-chloro-4-nitro aniline.

11. A method in accordance with Claim 1 wherein the reaction temperature falls within the range of about 80 up to 200°C.

12. A method in accordance with Claim 1 wherein the reaction time falls within the range of about 0.5 up to 24 hours.

13. A method in accordance with Claim 1 wherein said contacting is carried out in the further

presence of up to 5 wt % of a

transesterification catalyst.

14. Method for the functionalization of nucleophiles having the structural formula:

HY-R_x wherein Y is selected from nitrogen, oxygen or sulfur; wherein R is selected from: i) hydroxylated polyesters having a number average molecular weight in the range of about 500 up to 10,000, or ii) acrylic polymers containing free hydroxyl groups and having a number average

molecular weight in the range of about 500 up to 10,000; and wherein R can also be H when Y is N; and wherein x is 1 when Y is 0 or S, and x is 2 wheren Y is N; said process comprising contacting said nucleophile with a compound having the structure:

wherein

15. A method in accordance with Claim 14 wherein said nucleophile is selected from the group consisting of hydroxylated polyesters having the structure:

wherein each R⁷ and R^7' is independently selected from H, C₁ up to C₄ alkyl, hydroxy, or

alkoxy of the structure, -OZ, wherein Z is a hydrocarbyl moiety having in the range of 1 up to 6 carbon atoms; and each R⁸ and R^8' is independently selected from 1,2-arylene, 1,3-arylene, 1,4-arylene or an alkylene moiety of the structure:

-(CR⁹ ₂)_d- , wherein each R⁹ is independently selected from

H, C₁ up to C₄ alkyl, hydroxy or alkoxy of the structure -OZ, wherein Z Is a hydrocarbyl moiety having in the range of 1 up to 6 carbon atoms, and d is a whole number which can vary from 0 up to 24; a can vary from 1 up to 20;

b can vary from 2 up to 12; and

c can vary from 2 up to 12.

16. A method in accordance with Claim 15 wherein

said nucleophile is selected from hydroxylated polyesters having a number average molecular weight in the range of about 500 up to 6000 and comprising at least one diacid moiety selected from the group consisting of: phthalic acid,

terephthalic acid,

isophthalic acid

adipic acid,

1,4-cyclohexane dicarboxylic acid, 1,3-cyclohexane dicarboxylic acid,

1,2-cyclohexane dicarboxylic acid, and esters thereof; and at least one polyol selected from the group consisting of: ethylene glycol,

propylene glycol,

pentaerythritol,

neopentylglycol,

2,2,4-trimethyl-1,3-pentanediol, glycerol,

1,1,1-trimethylolpropane, and

1,1,1-trimethylolethane.

17. A method in accordance with Claim 14 wherein said nucleophile is selected from the group consisting of acrylic polymers prepared from hydroxyethyl methacrylate, hydroxyethyl

acrylate, 4-hydroxy butyl acrylate and/or

4-hydroxy butyl methacrylate, with at least one comonomer selected from the group consisting of: methyl acrylate,

ethyl acrylate,

propyl acrylate,

butyl acrylate,

methyl methacrylate,

ethyl methacrylate,

propyl methacrylate, and

butyl methacrylate.

18. A method in accordance with Claim 14 wherein

said acetoacetate is selected from t-butyl acetoacetate or t-amyl acetoacetate.

19. A method in accordance with Claim 14 wherein the reaction temperature falls within the range of about 80 up to 200°C.

20. A method in accordance with Claim 14 wherein the reaction time falls within the range of about 0.5 up to 24 hours.

21. A method in accordance with Claim 14 wherein

said contacting is carried out in the further presence of up to 5 wt % of a transesterification catalyst.