propylbenzene

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The starting material phenylpropane derivatives such as dihydroeugenol (n-Propyl guaiacol), 3,4-Methylenedioxy phenylpropane (dihydrosafrole), 4-Methoxyphenylpropane (dihydroanethole) or the like, can be obtained either from commercial sources or by catalytic hydrogenation of corresponding eugenol, safrole, anethole derivatives respectively (Steffen, A. In: Perfume and Flavor Chemicals, Allured Punlishing Corporation, 362 South Schmale Road, Carol Stream, Ill., USA, (1994)). In addition, 2,4,5-Trimethoxyphenylpropane can be obtained via ammonium formate assisted reduction of toxic β-asarone of Acorus calamus or crude calamus oil containing β-asarone (Sinha, A. K., U.S. Ser. No. 09/652,376 filed on Aug. 31, (2000)).

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In short, the present invention provides a process for the preparation of substituted trans-cinnamaldehyde, a natural yellow dye, from phenylpropane derivatives wherein R.sup.1 is fixed as a —CH═CH—CHO, however, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 are independently; i) a hydrogen atoms ii) a alkoxy group but atleast two of them from R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 are hydrogen atom or a alkoxy group but one methylenedioxy group with combination of either hydroxyl group, alkoxy group, alkyl group having 1-2 carbon atoms, aryl group or hydrogen atom or a alkoxy group but one hydroxyl group with combination of either methylenedioxy group, hydroxyl group, alkoxy group, alkyl group having 1-2 carbon atoms, aryl group or hydrogen atom; iii) a methylenedioxy with atleast three of them from R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 are combination of either alkoxy, hydroxy group, alkyl group having 1-2 carbon atoms, aryl group and hydrogen atom; iv) a hydroxyl group but atleast one of them from R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 is hydrogen atom with combination of either alkoxy, hydroxyl group, methylenedioxy group, alkyl group having 1-2 carbon atoms, aryl group or hydrogen atom; v) a protected hydroxyl group such as acetyl, benzyl, etc but atleast one of them from R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 is hydrogen atom with combination of either alkoxy, hydroxyl group, methylenedioxy group, alkyl group having 1-2 carbon atoms, aryl group and hydrogen atom or the like, obtained from corresponding (R2—R3—R4—R5—R6)phenylpropane derivatives (e.g. dihydro anethole where R2═R3═R5═R6 is H; R4 is —OMe; dihydro methyl eugenol where R2═R5═R6 is H; R3═R4 is —OMe and dihydro asarone where R2═R4═R5 is —OMe; R3═R6 is H etc) and the above process comprising the steps of (a) providing phenylpropane such as but not limited to 2,4,5-trimethoxyphenylpropane (dihydroasarone) in the following solvents namely ether such as but not limited to diethyl ether, tetrahydrofuran, dimethoxyethane, dioxane, diphenylether and the like; chlorinated solvents such as but not limited to dichloromethane, chloroform, o-dichlobenzene; an aromatic hydrocarbon such as but not limited to benzene, toluene, xylene; organic acid such as but not limited to formic acid, acetic acid and the like; (b) oxidation of phenylpropane derivatives in the presence of oxidizing reagents such as but not the limited to 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) or p-chloranil or pyridinium chlorochromate (PCC) or tBuOOH or CrO3 or a combination of reagents and the like and the amount thereof to be used is in the ration of 1-20 times moles, preferably 1.5-8 times moles, reaction temperature varies from −15° C. to +210° C., preferably 30° C. to 140° C., reaction period varies from 30 minutes to 48 hours, preferably 4-16 hours; (c) oxidation step proceeds more smoothly along with higher yield in presence of catalysts mainly mineral acid such as but not limited to hydrochloric acid, sulphuric acid or Cu(I) or Fe(III) salt or periodic acid or organic acid such as but not limited to acetic acid, propionic acid, butyric acid, ion exchange resin such as IR-120H, a sulphonated polystyrene resin, para-toluenesulphonic acid (PTSA) or amberlyst such as amberlyst 15 or absorbed above solution of phenylpropane and oxidising reagent on the following solid support such as but not limited to celite, silica gel, molecular sieve, alumina and the like in a short period ranging from 20 seconds to 12 minutes under microwave irradiation; (d) filtering the mixture and removing the solvent under reduced pressure, where the product is to be isolated in a conventional manner, i.e. extraction, distillation, recrystallization and chromatography and the yield of the product (e.g. 2,4,5-trimethoxycinnamaldehyde where R1 is —CH═CH—CHO, R2═R4═R5 is —OMe; R3═R6 is H; and 3,4-dimethoxycinnamaldehyde where R1 is —CH═CH—CHO, R2═R5═R6═H; R3═R4 is —OMe etc. in the above formula I) varies from 68-82%, preferably more in case of benzoquinone as a oxidising reagent.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Phenylglyoxal monohydrate (304 mg, 2 mM) and n-propylbenzene (0.56 ml, 4 mM) were dissolved in dichloroethane (6 ml), titanium tetrachloride (0.33 ml, 3 mM) was added, and reacted at room temperature for 2 hours. Using the same procedure as in Example 1, 4'-n-propylbenzoin was obtained as crystal (369.9 mg, 71.9% yield). reacted at room temperature for 2 hours

Conditions: temp:2.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a 250--mL RB flask fitted with pressure equalizing addition funnel, thermometer, magnetic stirrer, and N2 inlet was placed 0.75 g (3.0 mmol) of 4,4'-difluorobenzil, 13.8 mL (80 mmol) of 2,6-diisopropylaniline (DIPA), and 100 mL dry benzene. In the addition funnel was placed 50 mL of dry benzene and 210 mL (3.5 g; 18 mmol) of titanium tetrachloride. The reaction flask was cooled to 2° C. with ice and the TiCl4 solution was added dropwise over 45 min, keeping the reaction temperature below 5° C. The ice bath was removed after addition was complete and the mixture was stirred at RT for 72 h. The reaction mixture was partitioned between water and ethyl ether, and the ether phase was rotovapped and the concentrated oil was washed with 800 mL 1N HCl to remove the excess diisopropylaniline. The mixture was extracted with 100 mL of ether, and the ether layer was washed with water and rotovapped. Addition of 15 mL hexane plus 30 mL of methanol to the concentrate resulted in the formation of fine yellow crystals which were filtered, methanol-washed, and dried under suction to yield 0.4 g of (2,6--i--PrPh)2DAB(4--F--Ph)2, mp: 155°-158° C. In a 250--mL RB flask fitted with pressure addition funnel thermometer, magnetic stirrer, and N2 inlet was placed the reaction temperature below 5° C The ice bath was removed after addition The reaction mixture was partitioned between water and ethyl ether the concentrated oil was washed with 800 mL 1N HCl to remove the excess diisopropylaniline The mixture was extracted with 100 mL of ether the ether layer was washed with water Addition of 15 mL hexane plus 30 mL of methanol to the concentrate resulted in the formation of fine yellow crystals which were filtered methanol-washed dried under suction

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Particularly preferred reactions are that of toluene with ethene or propene to give propylbenzene or isobutylbenzene, that of cumene with ethene to give tert-amylbenzene, and that of xylenes with butadiene to give 5-tolylpentenes.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Into a 250-mL round-bottom flask was placed propylbenzene (20 g, 166.40 mmol, 1.00 equiv) and Fe (10 g, 178.57 mmol, 1.07 equiv). This was followed by the addition of Br2 (26.6 g, 166.45 mmol, 1.00 equiv) dropwise with stirring. The resulting solution was stirred overnight at room temperature. The reaction was then quenched by the addition of 100 mL of NaHSO3 (aq.). The mixture was extracted with 3×100 mL of ethyl acetate and the organic layers combined and dried over anhydrous sodium sulfate and concentrated under vacuum. Purification afforded 29.4 g (crude) of 1-bromo-2-propylbenzene as a yellow oil. Into a 250-mL round-bottom flask was placed The resulting solution was stirred overnight at room temperature The reaction was then quenched by the addition of 100 mL of NaHSO3 (aq.) The mixture was extracted with 3×100 mL of ethyl acetate dried over anhydrous sodium sulfate concentrated under vacuum Purification

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Into a 250-mL round-bottom flask was placed propylbenzene (20 g, 166.40 mmol, 1.00 equiv) and Fe (10 g, 178.57 mmol, 1.07 equiv). This was followed by the addition of Br2 (26.6 g, 166.45 mmol, 1.00 equiv) dropwise with stirring. The resulting solution was stirred overnight at room temperature. The reaction was then quenched by the addition of 100 mL of NaHSO3 (aq.). The mixture was extracted with 3×100 mL of ethyl acetate and the organic layers combined and dried over anhydrous sodium sulfate and concentrated under vacuum. Purification afforded 29.4 g (crude) of 1-bromo-2-propylbenzene as a yellow oil. Into a 250-mL round-bottom flask was placed The resulting solution was stirred overnight at room temperature The reaction was then quenched by the addition of 100 mL of NaHSO3 (aq.) The mixture was extracted with 3×100 mL of ethyl acetate dried over anhydrous sodium sulfate concentrated under vacuum Purification

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Crushed anhydrous aluminium trichloride (1.28 mole) was suspended in dry carbon disulphide (348 ml). Acetylchloride (1.1 mole) and n-propylbenzene (1.0 mole) was dissolved in dry carbon disulphide (348 ml) and added to the suspension of aluminium trichloride under anhydrous conditions. The mixture was then left to stir overnight. The solvent was distilled from the reaction mixture and the viscous residue poured onto crushed ice and stirred for 0.5 hours. The product was extracted into ether and the extract washed with water and dried (Na2SO4). The ether was removed by distillation and the oily residue distilled. The product had mpt 132° C. at 0.1 mm Hg. The mixture was then left The solvent was distilled from the reaction mixture the viscous residue poured onto crushed ice stirred for 0.5 hours The product was extracted into ether the extract washed with water dried (Na2SO4) The ether was removed by distillation the oily residue distilled

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The starting material phenylpropane derivatives such as dihydroeugenol (n-Propyl guaiacol), 3,4-Methylenedioxy phenylpropane (dihydrosafrole), 4-Methoxyphenylpropane (dihydroanethole) or the like, can be obtained either from commercial sources or by catalytic hydrogenation of corresponding eugenol, safrole, anethole derivatives respectively (Steffen, A. In: Perfume and Flavor Chemicals, Allured Punlishing Corporation, 362 South Schmale Road, Carol Stream, Ill., USA, (1994)). In addition, 2,4,5-Trimethoxyphenylpropane can be obtained via ammonium formate assisted reduction of toxic β-asarone of Acorus calamus or crude calamus oil containing β-asarone (Sinha, A. K., U.S. Ser. No. 09/652,376 filed on Aug. 31, (2000)).

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The starting material phenylpropane derivatives such as dihydroeugenol (n-Propyl guaiacol), 3,4-Methylenedioxy phenylpropane (dihydrosafrole), 4-Methoxyphenylpropane (dihydroanethole) or the like, can be obtained either from commercial sources or by catalytic hydrogenation of corresponding eugenol, safrole, anethole derivatives respectively (Steffen, A. In: Perfume and Flavor Chemicals, Allured Punlishing Corporation, 362 South Schmale Road, Carol Stream, Ill., USA, (1994)). In addition, 2,4,5-Trimethoxyphenylpropane can be obtained via ammonium formate assisted reduction of toxic β-asarone of Acorus calamus or crude calamus oil containing β-asarone (Sinha, A. K., U.S. Ser. No. 09/652,376 filed on Aug. 31, (2000)).