Alkyl trityl phenyl ethers

Abstract

A compound having formula (I) ##STR00001##
wherein R.sup.1 and R.sup.2 independently represent C.sub.1-C.sub.6 alkyl; R.sup.3 is C.sub.1-C.sub.6 alkyl; R.sup.4 is C.sub.1-C.sub.18 alkyl or C.sub.4-C.sub.18 heteroalkyl; m is zero, one, two or three; n is one, two or three; and j, k, p, q, r and s independently are zero, one or two; provided that at least one of j, k, p, q, r and s is not zero.

Claims

1. A compound having formula (I) ##STR00017## wherein R.sup.1 and R.sup.2 independently represent C.sub.1-C.sub.6 alkyl; R.sup.3 is C.sub.2-C.sub.6 alkyl; R.sup.4 is C.sub.1-C.sub.18 alkyl or C.sub.4-C.sub.18 heteroalkyl; m is one or two; n is one, two or three; and j, k, p, q, r and s independently are zero, one or two; provided that at least one of j, k, p, q, r and s is not zero.

2. The compound of claim 1 in which n is one or two; m is one; j, p and r are zero or one; and k, q and s are zero.

3. The compound of claim 2 in which R.sup.4 is C.sub.2-C.sub.12 saturated alkyl.

4. The compound of claim 3 in which R.sup.1 and R.sup.2 independently represent C.sub.1-C.sub.4 alkyl.

5. The compound of claim 4 in which R.sup.3 is C.sub.3-C.sub.6 alkyl.

6. The compound of claim 1 in which R.sup.3 is C.sub.3-C.sub.6 alkyl.

Description

EXAMPLES

(1) Common laboratory reagents and solvents were obtained from Sigma-Aldrich, Fluka, VWR, Acros, or Fisher Scientific, and were used as received. The benzoic acid esters, Grignard reagents and the phenols were obtained from Sigma-Aldrich.

(2) Analysis Procedures

(3) IR Analyses: IR analyses were performed using a Nicolet 560 FTIR spectrometer. For liquid samples, a small drop was cast as a neat film between two KBr plates. The IR spectrum was acquired in the transmission mode from 4000 to 400 cm.sup.1, with a spectral resolution of 4 cm.sup.1. A Happ-Genzel type apodization function was used.

(4) NMR Analyses: Both .sup.1H and .sup.13C NMR spectra were acquired using a Bruker 200 NMR spectrometer operating at 4.7 T. .sup.1H spectra were obtained using an 8.2 second accumulation time and 2.0 KHz sweep width; the .sup.13C spectra were obtained at a 4.7 second accumulation time and 7.0 KHz sweep width. Methanol-d.sub.4 was typically used as the solvent. Chemical shifts were referenced using the solvent resonances at 3.30 ppm for .sup.1H, and at 59.05 ppm for .sup.13C.

(5) GPC ANALYSES: GPC analyses to follow the progress of synthesis reactions and to determine product purity were performed using a PerkinElmer Series 200 HPLC. Two Polymer Laboratories pLgel columns were used in series: 1) 300 mm7.5 mm, 3 , 100 ; 2) 300 mm7.5 mm, 5 , 50 . These two columns are preceded by a guard column. The columns are maintained at 35 C. The mobile phase is 100% THF at a flow rate of 2 mL/minute. UV detection is at 270 nm. The program run time is 10 minutes.

(6) GC ANALYSES: GC analyses to follow the progress of synthesis reactions and to determine product purity were performed using a Hewlett Packard Model 6890N gas chromatograph with FID detector. The column was a Thermo Scientific TR5, 7 meter0.32 mm0.25 m film. The run program started with the oven at 50 C. with an initial hold time of 1 minute, followed by a temperature ramp up to 280 C. at 10 C./minute, and a final hold time of 20 minutes. The injection port temperature and detector temperatures were both 275 C. The sample injection size was 1 L, and the carrier gas was helium at 1 mL/minute.

(7) Melting Points: Melting points were determined using a Mel-Temp apparatus, and were uncorrected.

(8) Synthesis of Alkyl Trityl Alcohols

(9) General Synthesis Procedure: The following example is representative of the procedure used for the synthesis of all of the alkyl trityl alcohols. Synthesis data are summarized in Table 1 below.

(10) Phenyldi-m-tolylmethanol [95938-57-1] (mmMTritOH): A 500 mL 4-neck flask was equipped with a magnetic stir bar, a 60 mL addition funnel, and 4 glass stoppers. The equipment was dried overnight in a 125 C. oven. Upon removal from the oven, the equipment was quickly assembled and was cooled to room temperature under a stream of nitrogen. The flask was charged with 200 mL of 1.0 M m-tolyl magnesium chloride in THF (0.2 moles). The addition funnel was charged with 13.63 grams (0.1 mole) of methyl benzoate in 30 mL of dry THF. Under a nitrogen blanket, the methyl benzoate solution was added to the stirred Grignard solution dropwise over a period of about 2.5 hours. During the addition, the Grignard solution turned from a yellow-brown to a violet color. Shortly after the addition began, an exotherm to about 37 C. was observed. The addition rate was adjusted to keep the reaction mixture temperature at or below this temperature. After the addition was completed, the reaction mixture temperature was increased to 60 C. for 2.5 hours. The reaction mixture was then stirred at room temperature for several days. GC analysis of a sample of the reaction mixture showed the presence of unreacted benzoate ester. The reaction mixture was re-heated to 60-65 C., monitoring the formation of product by GC analysis. After about 10 hours, the amount of unreacted ester was slightly more than 2 area %, and the amount of mmMTritOH was >85 area %. The reaction mixture was poured onto a mixture of 100 mL of 10 volume % sulfuric acid in water and about 300 grams of ice. About 100 mL of ether was added, and the mixture was stirred until the ice melted. The mixture was transferred to a separatory funnel, and the layers were separated. The aqueous layer was extracted with 150 mL of ether, and the ether layers were combined. The combined ether layers were washed with 250 mL of saturated aqueous sodium bicarbonate solution and then with 250 mL of saturated aqueous sodium chloride solution. The ether solution was dried over anhydrous magnesium sulfate, then it was filtered and the solvent was removed by rotary evaporation to give 26.33 grams of mmMTritOH as a viscous amber oil. Yield=91.3%. Product purity by GC analysis was >91 area %. Product structure was confined by IR, .sup.1H and .sup.13C-NMR, and GC/MS analyses.

(11) Synthesis of Alkyl Trityl Phenols

(12) General Synthesis Procedure: The following example is representative of the procedure used for the synthesis of all of the alkyl trityl phenols. Synthesis data are summarized in Table 2 below.

(13) 2-(sec-Butyl)-4-(diphenyl)(p-tolyl)methyl)phenol (pMS4): A 100 mL 3-neck flask was equipped with a magnetic stirrer and a reflux condenser with nitrogen blanket. The flask was charged with 6.86 grams (0.025 moles) of diphenyl(p-tolyl)methanol (pMTritOH; [5440-76-6]), with 3.76 grams (0.025 moles) of o-sec-butylphenol, and with 50 mL of glacial acetic acid. The mixture was stirred under nitrogen at room temperature to give a clear yellow solution. To this solution were added 5 mL of concentrated sulfuric acid. The clear yellow acetic acid solution immediately turned deep red brown. The reaction mixture was stirred at room temperature, monitoring reaction progress by GPC analysis. After 6 days, the amount of remaining unreacted o-sec-butylphenol had decreased to about 7 area %, and the amount of mMS4 present had increased to about 83 area %. The reaction mixture was poured into about 250 mL of water and about 150 mL of toluene were added. The mixture was stirred at room temperature for about 1 hour, then the mixture was transferred to a separatory funnel. The layers were separated, and the aqueous layer was extracted with 1 x 50 mL of toluene, and the toluene layers were combined. The toluene solution was washed with 1100 mL of water, and with 1100 mL of saturated aqueous sodium chloride solution. The toluene solution was dried over anhydrous magnesium sulfate, then it was filtered and the solvent was removed by rotary evaporation to give 10 grams of pMS4 as a viscous dark red oil. Yield was 100%; product purity by GPC analysis was 82 area %. Product structure was confirmed by IR, .sup.1H and .sup.13C-NMR, and GC/MS analyses.

(14) Synthesis of Alkyl Trityl Phenyl Ethers

(15) General Synthesis Procedure: The following example is representative of the procedure used for the synthesis of all of the alkyl trityl phenyl ethers. Synthesis data are summarized in Table 3 below.

(16) ((3,4-Bis(hexyloxy)phenyl)(p-tolyl)methylene)dibenzene (pM3,4-6): A 100 mL 3-neck flask was equipped with a magnetic stirrer, a reflux condenser with nitrogen blanket, and a heating mantle with a temperature controller and a thermocouple. The flask was charged with 3.67 grams (0.01 mole) of 4-(diphenyl(p-tolyl)methyl)benzene-1,2-diol (pM3,4), 1.41 grams (0.21 moles) of 85% potassium hydroxide pellets, and with 25 mL of dimethyl sulfoxide. The mixture was stirred under nitrogen and was heated to 105 C. Heating and stirring were continued until all of the potassium hydroxide pellets were dissolved. A dark red brown solution was obtained. The reaction mixture was cooled to 55 C., and 3.30 grams (0.02 moles) of bromohexane were added in one portion. As exotherm to 66 C. was observed. The reaction mixture was then maintained at 65 C. and was monitored by GC analysis. After 2 hours, almost no pM3,4 remained. The reaction mixture was poured into about 250 mL of water containing a few pellets of potassium hydroxide and several grams of sodium chloride. About 150 mL of toluene were added, and the mixture was stirred at room temperature for about 1 hour. The mixture was transferred to a separatory funnel and the layers were separated. The aqueous layer was extracted with 150 mL of toluene, and the toluene layers were combined. The toluene solution was washed with 175 mL of saturated aqueous sodium chloride solution, and was then dried over anhydrous magnesium sulfate. The solvent was removed by rotary evaporation to give 3.80 grams of pM3,4-6 as a dark red oil. Yield was 71%. Purity was >90 area % by GC. Product structure was confirmed by IR, .sup.1H and .sup.13C-NMR, and GC/MS analyses.

(17) Candidate Assessment Studies

(18) GC/MS Studies: Stock solutions of alkyl trityl phenyl ether candidate were prepared in dichloromethane (DCM). These DCM solutions were used to establish GC retention times and MS fragmentation patterns. A summary of GC retention times and MS fragmentation data are summarized in Table 4 below.

(19) GC/MS Parameters: Column: Agilent DB 35 m, 15.0 m0.25 mm0.25 Flow Rate: 1.5 mL/min He carrier gas Oven: initial: 100 C. Ramp 1: 20 C./min to 280 C.; Hold: 10 min. Ramp 2: 20 C./min to 340 C.; Hold: 6 min Inlet Temp.: 280 C. Insert: Splitless; Vent: 15 min , Single taper, glass wool, deactivated, 5062-3587 Injection Volume: 3 L; Viscosity: 5 sec., Plunger: fast Mass Transfer Line Temp.: 280 C. MS Quad: 200 C.; MS Source: 250 C. Solvent Delay: 18.5 min

(20) Solubility Studies: The solubility properties of the alkyl trityl phenyl ethers were determined by mixing 0.1 grams of test sample with 0.9 grams of solvent. The mixtures were warmed to 60 C. for a few minutes to make homogeneous solutions. The solutions were cooled back to room temperature, and then they were placed into a freezer at 10 C. The solutions were checked daily to see if crystallization had occurred. The solvents evaluated were ADVASOL 200H (mixed aromatics solvent from Advanced Aromatics), ADVASOL 200H ND (naphthalene-depleted mixed aromatics solvent from Advanced Aromatics), cyclohexanone, and o-sec-butyl phenol (OSBP). Solubility data results are summarized in Table 5 below.

(21) Assessment Summary: The GC retention time, GC/MS fragmentation and solubility performance results of the alkyl trityl phenyl ethers were all favorable for application as fuel markers.

(22) TABLE-US-00001 TABLE 1 Synthesis Data for Alkyl Trityl Alcohols % GC Area % STRUCTURE Designation M.W. Yield Purity mp, C. pMTritOH 274.36 92.2 96.4 78-79 mmMTritOH 288.38 90 >91 oil ommMTritOH 302.41 88.5 >51 oil

(23) TABLE-US-00002 TABLE 2 Synthesis Data for Alkyl Trityl Phenols GPC (GC) Area % STRUCTURE Designation M.W. % yield Purity mp, C. pMS4 406.56 100 82 oil pM3,4 366.45 55 89 175-180 0 mmMS4 420.59 78 (75) oil

(24) TABLE-US-00003 TABLE 3 Synthesis Data for Alkyl Trityl Phenyl Ethers GPC (GC) Area % STRUCTURE Designation M.W. % yield Purity mp, C. pMS4-10 546.82 89 (>75) oil pM3,4-6 534.77 71 >90 oil mmMS4-10 560.40 79.6 (70) oil

(25) TABLE-US-00004 TABLE 4 Summary of GC Retention Time and GC/MS Fragmentation Data for Alkyl Trityl Phenyl Ethers GC GC/MS Retention Major Ion STRUCTURE DESIGNATION M.W. Time, Min. Masses, m/e pMS4-10 546.82 22.24 546, 469 pM3,4-6 534.77 22.89 534, 457, 373 mmMS4-10 560.40 21.69 560, 469

(26) TABLE-US-00005 TABLE 5 Solubility Data Summary for Alkyl Trityl Phenyl Ethers WT. % Alkyl Alkyl Trityl Trityl Phenyl Phenyl Solubility at 10 C., Ether Ether SOLVENT SYSTEM Days pMS4-10 10 200H - OSBP (75:25, Soluble after 7 days w:w) 200H ND - OSBP (75:25, Soluble after 7 days w:w) 200H Soluble after 7 days 200H ND Soluble after 7 days 200H - cyclohexanone Soluble after 7 days (75:25, w:w) 200H ND - cyclohexanone Soluble after 7 days (75:25, w:w) pM3,4-6 10 200H - OSBP (75:25, Soluble after 76 days w:w) 200H ND - OSBP (75:25, Soluble after 76 days w:w) 200H Soluble after 18 days; crystals after 35 days 200H ND Soluble after 18 days; crystals after 35 days 200H - cyclohexanone Soluble after 7 days (75:25, w:w) 200H ND - cyclohexanone Soluble after 7 days (75:25, w:w) mmMS4- 10 200H - OSBP (75:25, Soluble after 102 10 w:w) days 200H - cyclohexanone Soluble after 102 (75:25, w:w) days