1207-12-1

Basic information

• Product Name: 4,6-DIMETHYLDIBENZOTHIOPHENE
• Synonyms: 4,6-diMethyldibenzo[b,d]thiophene;6-DMDBT;4,6-dimethyl-dibenzothiophen;Dibenzothiophene, 4,6-dimethyl-;4,6-DMDBT;4,6-DIMETHYLDIBENZOTHIOPHENE;4,6-Dimethyldibenzothiophene ,97%
• CAS NO: 1207-12-1
• Molecular Formula: C₁₄H₁₂S
• Molecular Weight: 212.31
• EINECS: 214-894-7
• Product Categories: API intermediates;Benzothiophenes;Building Blocks;Heterocyclic Building Blocks
• Mol File: 1207-12-1.mol
• Article Data: 16

Chemical Properties

• Melting Point: 153-157 °C(lit.)
• Boiling Point: 312.16°C (rough estimate)
• Flash Point: 130.2 °C
• Appearance: White to beige/Crystalline Powder or Crystals
• Density: 1.1405 (rough estimate)
• Vapor Pressure: 3.42E-05mmHg at 25°C
• Refractive Index: 1.6170 (estimate)
• Storage Temp.: Keep in dark place,Sealed in dry,Room Temperature
• CAS DataBase Reference: 4,6-DIMETHYLDIBENZOTHIOPHENE(CAS DataBase Reference)
• NIST Chemistry Reference: 4,6-DIMETHYLDIBENZOTHIOPHENE(1207-12-1)
• EPA Substance Registry System: 4,6-DIMETHYLDIBENZOTHIOPHENE(1207-12-1)

Safety Data

• Safety Statements: 24/25
• WGK Germany: 3
• TSCA: Yes
• Hazardous Substances Data: 1207-12-1(Hazardous Substances Data)

Usage

Description

4,6-Dimethyldibenzothiophene (4,6-DMDBT) is a high refractory sulfur compound that is typically found in diesel fuel. It is a light yellow to light brown crystalline solid and is known for its role in petroleum desulfurization studies. The synthesis and hydrodesulfurization of 4,6-DMDBT have been extensively reported, with various methods being explored to improve its removal from diesel fuel.

Uses

Used in Petroleum Industry:
4,6-Dimethyldibenzothiophene is used as a target compound in petroleum desulfurization for the reduction of sulfur content in diesel fuel. The application reason is to meet environmental regulations and improve the quality of diesel fuel, as 4,6-DMDBT is a challenging compound to remove due to its high refractory nature.
In the field of petroleum desulfurization, various methods have been employed to hydrodesulfurize 4,6-DMDBT, including the use of bulk nickel alloy, bulk tungsten phosphide (WP), NiMo sulfide supported on active carbons, and molecularly imprinted polymers. These methods aim to enhance the efficiency of sulfur removal from diesel fuel, thereby reducing its environmental impact and improving fuel quality.
Additionally, the dielectric behavior of 4,6-DMDBT under different microwave frequencies and temperature has been investigated, which could potentially lead to the development of new desulfurization techniques that utilize microwave energy to facilitate the removal of sulfur compounds from diesel fuel.

InChI:InChI=1/C14H12S/c1-9-5-3-7-11-12-8-4-6-10(2)14(12)15-13(9)11/h3-8H,1-2H3

Synthetic route

Dimethyl-thiocarbamic acid O-(2'-dimethylthiocarbamoyloxy-3,3'-dimethyl-biphenyl-2-yl) ester (190841-62-4) → Dimethyl-thiocarbamic acid S-(2'-dimethylcarbamoylsulfanyl-3,3'-dimethyl-biphenyl-2-yl) ester + 4,6-dimethyldibenzothiophene (1207-12-1)

Conditions	Yield
at 285℃; for 0.366667h;	A 80% B 20%

2,2′-sulfinylbis(methylbenzene) (5097-05-2) → 4,6-dimethyldibenzothiophene (1207-12-1)

Conditions	Yield
With ruthenium(III) chloride trihydrate; silver carbonate; trifluoroacetic acid at 140℃; for 20h; Inert atmosphere;	78%

di-o-tolyl sulfide (4537-05-7) → 4,6-dimethyldibenzothiophene (1207-12-1)

Conditions	Yield
With palladium(II) trifluoroacetate; silver(I) acetate; potassium carbonate at 130℃; for 24h; Schlenk technique;	75%

3-methyl-2-[(2-methylphenyl)sulfanyl]cyclohex-2-en-1-one → 4,6-dimethyldibenzothiophene (1207-12-1) + 1,2,3,4-tetrahydro-4,6-dimethyldibenzo[b,d]thiophene (89816-78-4)

Conditions	Yield
With polyphosphonic acid; air at 150℃;	A 60% B 19%

dibenzothiophene (132-65-0) + methyl iodide (74-88-4) → 4,6-dimethyldibenzothiophene (1207-12-1)

Conditions	Yield
Stage #1: dibenzothiophene With n-butyllithium; N,N,N,N,-tetramethylethylenediamine In hexane at -78℃; Stage #2: methyl iodide	49%
With n-butyllithium; N,N,N,N,-tetramethylethylenediamine In hexane at -15 - 20℃; for 12h;	45%
With n-butyllithium; N,N,N,N,-tetramethylethylenediamine 1.) hexane, 60 deg C, 2 h, 2.) hexane, from -78 deg C to RT, 12 h; Yield given. Multistep reaction;
With n-butyllithium 1) Et2O; Multistep reaction;

2-methylphenyl 2-methyl-6-diazophenyl sulfide fluoroborate → 4,6-dimethyldibenzothiophene (1207-12-1)

Conditions	Yield
With copper In dimethyl sulfoxide for 2h; Ambient temperature;	26%

3,3'-dimethyl-[1,1'-biphenyl]-2,2'-diol (32750-14-4) → 4,6-dimethyldibenzothiophene (1207-12-1)

Conditions	Yield
With phosphorous (V) sulfide at 410℃;
Multi-step reaction with 2 steps 1: 85 percent / NaH / dimethylformamide / 1 h / 85 °C 2: 20 percent / 0.37 h / 285 °C View Scheme

4-methyldibenzothiophene (7372-88-5) + dimethyl sulfate (77-78-1) → 4-Ethyldibenzothiophene (89816-99-9) + 4,6-dimethyldibenzothiophene (1207-12-1)

Conditions	Yield
With n-butyllithium 1) THF, Et2O, hexane, reflux, 1 h, 2) reflux, 1 h; Yield given. Multistep reaction. Yields of byproduct given;

2-thiocresol (137-06-4) + 3-Methylcyclohexanone (591-24-2, 625-96-7) → 2,6-dimethyldibenzothiophene (89816-75-1) + 4,6-dimethyldibenzothiophene (1207-12-1)

Conditions	Yield
With sodium hydroxide; selenium; PPA; bromine Yield given. Multistep reaction. Yields of byproduct given;

2,2'-dimethoxy-3,3'-dimethyl-1,1'-biphenyl (32750-25-7) → 4,6-dimethyldibenzothiophene (1207-12-1)

Conditions	Yield
Multi-step reaction with 3 steps 1: 95 percent / BBr3 / CH2Cl2 / 4 h / -78 - 20 °C 2: 85 percent / NaH / dimethylformamide / 1 h / 85 °C 3: 20 percent / 0.37 h / 285 °C View Scheme

4,6-dimethyldibenzothiophene sulfone (6909-77-9) → 2-hydroxy-3,3'-dimethylbiphenyl (78210-32-9) + 4,6-dimethyldibenzothiophene (1207-12-1)

Conditions	Yield
Stage #1: 4,6-dimethyldibenzothiophene sulfone With sodium hydroxide In water at 300℃; for 1.5h; Autoclave; Stage #2: With hydrogenchloride In Dichlorofluoromethane; water pH=7; Product distribution / selectivity;

2-methylphenyl 2-methyl-6-aminophenyl sulfide → 4,6-dimethyldibenzothiophene (1207-12-1)

Conditions	Yield
With tetrafluoroboric acid; palladium diacetate; sodium nitrite In tetrahydrofuran; water at 0 - 60℃;

1,2,3,4-tetrahydro-4,6-dimethyldibenzo[b,d]thiophene (89816-78-4) → 4,6-dimethyldibenzothiophene (1207-12-1) + 1,2,3,4,4a,9b-hexahydro-4,6-dimethyldibenzothiophene

Conditions	Yield
With piperidine; nickel phosphide; hydrogen In decalin at 340℃; under 30003 Torr; Kinetics; Reagent/catalyst; Flow reactor;

1,2,3,4-tetrahydro-4,6-dimethyldibenzo[b,d]thiophene (89816-78-4) → 3,6-dimethyldibenzo[b,d]thiophene (31613-04-4) + 4,6-dimethyldibenzothiophene (1207-12-1)

Conditions	Yield
With tungsten phosphide; hydrogen In decalin at 240℃; under 30003 Torr;

1,2,3,4,4a,9b-hexahydro-4,6-dimethyldibenzothiophene → 3,6-dimethyldibenzo[b,d]thiophene (31613-04-4) + 4,6-dimethyldibenzothiophene (1207-12-1)

Conditions	Yield
Multi-step reaction with 2 steps 1: hydrogen; tungsten phosphide / decalin / 240 °C / 30003 Torr 2: hydrogen; tungsten phosphide / decalin / 240 °C / 30003 Torr View Scheme

α-bromo-3-methylcyclohex-2-en-1-one (51326-26-2) + 2-thiocresol (137-06-4) → 4,6-dimethyldibenzothiophene (1207-12-1) + 1,2,3,4-tetrahydro-4,6-dimethyldibenzo[b,d]thiophene (89816-78-4)

Conditions	Yield
Stage #1: α-bromo-3-methylcyclohex-2-en-1-one; 2-thiocresol Stage #2: With polyphosphoric acid

2-thiocresol (137-06-4) → 3,6-dimethyldibenzo[b,d]thiophene (31613-04-4) + 4,6-dimethyldibenzothiophene (1207-12-1)

Conditions	Yield
Multi-step reaction with 2 steps 1.2: polyphosphoric acid 2.1: hydrogen; tungsten phosphide / decalin / 240 °C / 30003 Torr View Scheme

4,6-dimethyldibenzothiophene (1207-12-1) → 4,6-dimethyldibenzothiophene sulfone (6909-77-9)

Conditions	Yield
With tert.-butylhydroperoxide; [(η5-C5H5)Mo(CO)3Cl] In decane; dichloromethane at 20℃; for 5h;	100%
With oxygen In decalin at 90℃; under 760.051 Torr; for 7h;	100%
With phthalic anhydride; urea hydrogen peroxide adduct In ethyl acetate at 20℃; Green chemistry;	100%

trisilver(I) tris(3,5-bis(trifluoromethyl)pyrazolate) (274249-48-8) + 4,6-dimethyldibenzothiophene (1207-12-1) → C15H3Ag3F18N6*C14H12S

Conditions	Yield
In dichloromethane at 5℃; for 48h; Solvent;	90%

4,6-dimethyldibenzothiophene (1207-12-1) → 3,3'-dimethyl-biphenyl (612-75-9)

Conditions	Yield
With 3-Hydroxy-1-methylpiperidine; nickel diacetate; sodium hydride In tetrahydrofuran at 65℃; for 20h;	85%
With sodium tetrahydroborate; nickel dichloride In tetrahydrofuran; methanol for 1h; Ambient temperature;	29 % Chromat.
With dodecane; hydrogen sulfide; hydrogen; molybdenum In toluene at 300℃; under 37503.8 Torr; Product distribution; Kinetics; Further Variations:; Catalysts; Reagents; Pressures;

dimethylsilicon dichloride (75-78-5) + 4,6-dimethyldibenzothiophene (1207-12-1) → 4,5,5,6-tetramethyl-5H-dibenzo[b,d]silole

Conditions	Yield
Stage #1: 4,6-dimethyldibenzothiophene With N,N,N,N,-tetramethylethylenediamine; lithium In tetrahydrofuran at 20℃; for 7h; Schlenk technique; Inert atmosphere; Stage #2: dimethylsilicon dichloride In tetrahydrofuran at -78 - 20℃; Inert atmosphere; Schlenk technique;	83%

4,6-dimethyldibenzothiophene (1207-12-1) → 4,6-dimethyldibenzothiophene sulfone (6909-77-9) + 4,6-dimethyldibenzo[b,d]thiophene-5-oxide

Conditions	Yield
With tert.-butylhydroperoxide In octane at 59.84℃; for 0.5h; Catalytic behavior; Reagent/catalyst;	A 82.1% B 17.9%
With tert.-butylhydroperoxide; [MoO3(2,2′-bipyridine)]n In decane; dichloromethane at 40℃; for 20h;	A 30% B 56%
With tert.-butylhydroperoxide; [VIVO(N,N-bis(o-hydroxybenzaldehyde)phenylene diamine)] at 40℃; for 6h; Catalytic behavior;	A 53% B 11%

4,6-dimethyldibenzothiophene (1207-12-1) → 4,6-dimethyldibenzo[b,d]thiophene-5-oxide

Conditions	Yield
With dioxofluoro(bis-dimethylpyrazole) vanadium(V); dihydrogen peroxide In water; acetonitrile at 0 - 20℃; for 12h; Cooling with ice;	80%
With boron trifluoride diethyl etherate; 3-chloro-benzenecarboperoxoic acid In hexane; dichloromethane at -30℃; Inert atmosphere;	70%
With dihydrogen peroxide In dichloromethane at 60℃; for 4h; Catalytic behavior;	55%

4,8-dinitro-1,5-dichloroanthraquinone (6305-89-1) + 4,6-dimethyldibenzothiophene (1207-12-1) → 4,6-dimethyldibenzothiophene:1,5-dichloro-4,8-dinitroanthraquinone

Conditions	Yield
In N,N-dimethyl-formamide	80%

4,6-dimethyldibenzothiophene (1207-12-1) → 3,7-dibromo-4,6-dimethyldibenzo[b,d]thiophene (1055331-35-5)

Conditions	Yield
With bromine; acetic acid at 20℃; for 16h;	73%
With bromine In acetic acid at 20℃; for 16h;

1-chloro 4-iodobutane (10297-05-9) + 4,6-dimethyldibenzothiophene (1207-12-1) → C18H20ClS(1+)*BF4(1-)

Conditions	Yield
With silver tetrafluoroborate In 1,2-dichloro-ethane at 25℃; Inert atmosphere;	71%

C42H60Ag6N18O12 + 4,6-dimethyldibenzothiophene (1207-12-1) → C21H30Ag3N9O6*C14H12S

Conditions	Yield
In diethyl ether; dichloromethane at 20℃; for 72h;	70%

4-chlorobutyl bromide (6940-78-9) + 4,6-dimethyldibenzothiophene (1207-12-1) → C18H20ClS(1+)*BF4(1-)

Conditions	Yield
With silver tetrafluoroborate In 1,2-dichloro-ethane at 25℃; Inert atmosphere;	68%

C21H30Cu3N9O6 + 4,6-dimethyldibenzothiophene (1207-12-1) → C21H30Cu3N9O6*C14H12S

Conditions	Yield
In diethyl ether; dichloromethane at 20℃; for 72h;	64%

4,6-dimethyldibenzothiophene (1207-12-1) → (4RS,4aSR,9bSR)-4,6-dimethyl-1,2,3,4,4a,9b-hexahydrodibenzothiophene + (4RS,4aRS,9bRS)-4,6-dimethyl-1,2,3,4,4a,9b-hexahydrodibenzothiophene + (4RS,4aRS,9bSR)-4,6-dimethyl-1,2,3,4,4a,9b-hexahydrodibenzothiophene + (4RS,4aSR,9bRS)-4,6-dimethyl-1,2,3,4,4a,9b-hexahydrodibenzothiophene

Conditions	Yield
With hydrogen; palladium on activated charcoal In acetic acid at 200℃; under 112511 Torr; for 5h;	A 63% B 28% C 9% D n/a
With hydrogen; palladium on activated charcoal In acetic acid at 260℃; under 112509 Torr; for 2h; Further byproducts given;	A 31.5 % Chromat. B 49.8 % Chromat. C 2.1 % Chromat. D 16.6 % Chromat.

4,6-dimethyldibenzothiophene (1207-12-1) → 3,3'-dimethyl-biphenyl (612-75-9) + 3,3'-dimethylbicyclohexyl (103272-52-2) + 1-methyl-3-(3-methylphenyl)cyclohexane + 1,2,3,4,4a,9b-hexahydro-4,6-dimethyldibenzothiophene + 1,2,3,4-tetrahydro-4,6-dimethyldibenzo[b,d]thiophene (89816-78-4)

Conditions	Yield
With hydrogen sulfide; hydrogen In Hexadecane at 300℃; under 54755.5 Torr; for 8h; Catalytic behavior; Reagent/catalyst; Inert atmosphere;	A 8.2% B 13.3% C 49% D 10.3% E 19.2%
With hydrogen sulfide; hydrogen In Hexadecane at 300℃; under 54755.5 Torr; for 8h; Catalytic behavior; Reagent/catalyst; Inert atmosphere;	A 11.3% B 9.5% C 48.4% D 10.3% E 20.5%
With hydrogen at 299.84℃; under 37503.8 Torr;	A n/a B n/a C 72 %Chromat. D n/a E n/a

[(dippe)Pt(H)]2 (936548-34-4) + 4,6-dimethyldibenzothiophene (1207-12-1) → Pt(dippe)(SC14H12) (210758-50-2)

Conditions	Yield
In tetrahydrofuran byproducts: H2; excess of ligand, 120°C, 10 h; crystn. on cooling (0°C); NMR-spectroscopy;	40%

4,6-dimethyldibenzothiophene (1207-12-1) → 3,3'-dimethyl-biphenyl (612-75-9) + 3,3'-dimethylbicyclohexyl (103272-52-2) + 1-methyl-3-(3-methylphenyl)cyclohexane

Conditions	Yield
With hydrogen In cyclohexane at 280 - 300℃; under 30003 Torr; for 6h; Catalytic behavior; Reagent/catalyst; Flow reactor;	A 5.8% B 9.4% C 34.5%
With α-picoline; aluminum oxide; nickel molybdenum; hydrogen In toluene at 340℃; Product distribution; Further Variations:; Reagents; Temperatures; Solvents;
With hydrogen at 339.85℃; under 23251.9 Torr; Product distribution; Further Variations:; Catalysts;

4,6-dimethyldibenzothiophene (1207-12-1) → 3-bromo-4,6-dimethyldibenzo[b,d]thiophene (1055331-37-7)

Conditions	Yield
With bromine; acetic acid at 20℃; for 16h;	34%
With bromine In acetic acid at 20℃; for 16h;

[Rh2(1,2-bis(diisopropylphosphino)ethane)2(μ-SC12H9)(μ-H)] (1228530-60-6) + 4,6-dimethyldibenzothiophene (1207-12-1) → [Rh2(1,2-bis(diisopropylphosphino)ethane)2(μ-SH)(μ-H)] + [Rh2(1,2-bis(diisopropylphosphino)ethane)2(μ-SC12H7Me2)(μ-H)]

Conditions	Yield
With H2 In toluene (N2); soln. of Rh complex and dibenzothiophene (17-20 equiv.) in toluenein NMR tube was freeze-pump-thaw degassed; H2 (1 atm) was added; heated at 135°C for 8.5 d; NMR monitoring; evapd. (vac.); extd. (hexane); evapd.; dissolved in hexane; chromd. (silica, hexane, C6H6); evapd.;	A n/a B 24%

4,6-dimethyldibenzothiophene (1207-12-1) → 4,6-dimethyl-2,3,4,4a-tetrahydrodibenzothiophene + 4,6-dimethyl-1,2,3,9b-tetrahydrodibenzothiophene + 3,3'-dimethyl-biphenyl (612-75-9) + 1,2,3,4-tetrahydro-4,6-dimethyldibenzo[b,d]thiophene (89816-78-4)

Conditions	Yield
With hydrogen sulfide; hydrogen; molybdenum In toluene at 320℃; under 37503 Torr; for 240h; Further byproducts given;	A n/a B n/a C n/a D 13.7%

methanol (67-56-1) + 4,6-dimethyldibenzothiophene (1207-12-1) → 4-methyldibenzothiophene (7372-88-5) + biphenyl (92-52-4) + 3,3'-dimethyl-biphenyl (612-75-9) + 3-methylbiphenyl (643-93-6)

Conditions	Yield
catalyst CMA-1; Co(II),Mo(VI),Al(III) at 450℃; Product distribution;	A 6% B n/a C 9% D 7%

4,6-dimethyldibenzothiophene (1207-12-1) → 3,3'-dimethyl-biphenyl (612-75-9) + 1-methyl-3-(3-methylphenyl)cyclohexane

Conditions	Yield
With hydrogen; Co-Mo-Al (sulfided) at 360℃; under 40503.2 Torr; Rate constant; Product distribution; Mechanism; other supported catalysts Co-Mo and Ni-Mo also with zeolites;
With hydrogen; CMLX In various solvent(s) at 340℃; for 2h; Product distribution; Kinetics; Further Variations:; Catalysts; reaction times;
With molybdenum carbide; hydrogen; aluminium In decalin at 339.85℃; under 30002.4 Torr; Kinetics; Product distribution; Further Variations:; Reagents;

Upstream product

• 32750-14-4 3,3'-dimethyl-[1,1'-biphenyl]-2,2'-diol 
• 7372-88-5 4-methyldibenzothiophene 
• 77-78-1 dimethyl sulfate 
• 137-06-4 2-thiocresol 
• 591-24-2 3-Methylcyclohexanone 
• 132-65-0 dibenzothiophene 
• 74-88-4 methyl iodide 
• 190841-62-4 Dimethyl-thiocarbamic acid O-(2'-dimethylthiocarbamoyloxy-3,3'-dimethyl-biphenyl-2-yl) ester 
• 32750-25-7 2,2'-dimethoxy-3,3'-dimethyl-1,1'-biphenyl 
• 6909-77-9 4,6-dimethyldibenzothiophene sulfone 
• 4537-05-7 du-o-tolyl sulfide 
• 89816-78-4 1,2,3,4-tetrahydro-4,6-dimethyldibenzo[b,d]thiophene 
• 51326-26-2 α-bromo-3-methylcyclohex-2-en-1-one 
• 5097-05-2 2,2′-sulfinylbis(methylbenzene) 

Downstream Products

• 7372-88-5 4-methyldibenzothiophene 
• 92-52-4 biphenyl 
• 612-75-9 3,3'-dimethyl-biphenyl 
• 643-93-6 3-methylbiphenyl 
• 132034-91-4 4,6-Diethyldibenzothiophene 
• 103272-52-2 3,3'-dimethylbicyclohexyl 
• 89816-78-4 1,2,3,4-tetrahydro-4,6-dimethyldibenzo[b,d]thiophene 
• 104453-08-9 (1,1,1-tris(diphenylphosphinomethyl)ethane)Ir(H)3 
• 104437-87-8 IrH(CH₃C(CH₂P(C₆H₅)2)3)(CO) 
• 1055331-35-5 3,7-dibromo-4,6-dimethyldibenzo[b,d]thiophene 
• 1055331-37-7 3-bromo-4,6-dimethyldibenzo[b,d]thiophene 
• 108-88-3 toluene 
• 82166-21-0 methyl cyclohexane 

Relevant articles and documents

An efficient synthesis of pure 4,6-dimethyldibenzothiophene

The synthesis of substituted dibenzothiophenes in the 4 and/or 6 positions has been optimized and pure 4,6-dimethyldibenzothiophene has been prepared by a new selective method; X-ray analysis of this compound is described.

Preparation of partially hydrogenated 4,6-dimethyldibenzothiophenes

The synthesis of three key intermediates of the hydrogenation pathway in the hydrodesulfurization of 4,6-dimethyldibenzothiophene (4,6-DM-DBT; 1) is described. The hydrogenated derivatives 1,2,3,4-tetrahydro-4,6- dimethyldibenzothiophene (=4,6-dimethyl-1,2,3,4-tetrahydrodibenzothiophene; 4,6-DM-TH-DBT; 2), 1,2,3,4,4a,9b-hexahydro-4,6-dimethyldibenzothiophene (=4,6-dimethyl-1,2,3,4,4a,9b-hexahydrodibenzothiophene; 4,6-DM-HH-DBT; 3), and dodecahydro-4,6-dimethyldibenzothiophene (=4,6-dimethylperhydrodibenzothiophene; 4,6-DM-PH-DBT; 4) were prepared by direct hydrogenation of 1. The reactions were carried out in continuous and batch reactors by using metal sulfide as well as noble-metal catalysts. The influence of the reaction conditions on the formation of the products and the distribution of their stereoisomers was studied in detail. The isomers of the main products were isolated and characterized by NMR, GC/MS/MS, and X-ray crystal-structure diffractometry.

Hydrodesulfurization of 4,6-dimethyldibenzothiophene and its hydrogenated intermediates over bulk Ni2P

The hydrodesulfurization (HDS) of 4,6-dimethyldibenzothiophene (4,6-DMDBT) and its hydrogenated intermediates 1,2,3,4-tetrahydro-4,6- dimethyldibenzothiophene (TH-4,6-DMDBT) and 1,2,3,4,4a,9b-hexahydro-4,6- dimethyldibenzothiophene (HH-4,6-DMDBT) over a bulk Ni2P catalyst was studied at 340 °C and 4.0 MPa in the presence and absence of piperidine. The rate constants of all steps in the network of the HDS of 4,6-DMDBT were measured. The HDS of 4,6-DMDBT occurred predominantly through the hydrogenation (HYD) pathway, and the HYD and direct desulfurization pathways were about equally inhibited by piperidine. Piperidine inhibited the desulfurization of TH-4,6-DMDBT and 4,6-DMDBT in the same way, but did not affect that of HH-4,6-DMDBT. In contrast to the HDS of TH-4,6-DMDBT over metal sulfide catalysts and to the HDS of TH-DBT, a fast dehydrogenation of TH-4,6-DMDBT to 4,6-DMDBT was observed. Besides 4,6-DMDBT, a small amount of the methyl-migration isomers was detected in the dehydrogenation product of TH-4,6-DMDBT, which is ascribed to the metallic character of Ni2P.

Hydrodesulfurization of dibenzothiophene, 4,6-dimethyldibenzothiophene, and their hydrogenated intermediates over bulk tungsten phosphide

The kinetics of the hydrodesulfurization (HDS) of dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT), and their hydrogenated intermediates over bulk tungsten phosphide (WP) was studied. WP possessed high hydrogenation/dehydrogenation activity but was highly sensitive to piperidine inhibition. 4,6-DMDBT reacted faster than DBT, and both DBT and 4,6-DMDBT reacted mainly through the hydrogenation pathway. The methyl groups suppressed the direct desulfurization of 4,6-DMDBT but significantly promoted the hydrogenation of 4,6-DMDBT and the dehydrogenation of 1,2,3,4-tetrahydro-4,6-dimethyldibenzothiophene (TH-4,6-DMDBT) and 1,2,3,4,4a,9b-hexahydro-4,6-dimethyldibenzothiophene, but decreased the rate of hydrogenation of TH-4,6-DMDBT. Piperidine inhibited the HDS of 4,6-DMDBT much more strongly than that of DBT. Substantial dehydrogenation of TH-4,6-DMDBT to 4,6-DMDBT and two of its isomers occurred. The formation of these 4,6-DMDBT isomers in the dehydrogenation of TH-4,6-DMDBT and the hydrocracking of 1-methyl-4-(3-methylcyclohexyl)-benzene, as well as the formation of cyclopentylphenylmethane and (cyclopentylmethyl)cyclohexane, is ascribed to the metallic character of WP.