626-05-1

Basic information

• Product Name: 2,6-Dibromopyridine
• Synonyms: 2,6-DIBROMOPYRIDINE;2,6-dibromo-pyridin;2,6-Dibromopyridine,98%;Pyridine, 2,6-dibromo-;2,6-DibroMopyridine, 98% 25GR;2,4-dibroMo-6-nitropyridine
• CAS NO: 626-05-1
• Molecular Formula: C₅H₃Br₂N
• Molecular Weight: 236.89
• EINECS: 210-926-9
• Product Categories: Pyridine;Pyridine Series;Pyridines, Pyrimidines, Purines and Pteredines;Pyridines;Bromopyridines;Halopyridines;C5Heterocyclic Building Blocks;Halogenated Heterocycles;Heterocyclic Building Blocks;Building Blocks;C5;Chemical Synthesis;Halogenated Heterocycles;Heterocyclic Building Blocks;alkyl bromide
• Mol File: 626-05-1.mol

Chemical Properties

• Melting Point: 117-119 °C(lit.)
• Boiling Point: 255°C
• Flash Point: 213 °C
• Appearance: White to gray or buff/Crystalline Powder
• Density: 2.0383 (rough estimate)
• Vapor Pressure: 0.0255mmHg at 25°C
• Refractive Index: 1.5800 (estimate)
• Storage Temp.: Store below +30°C.
• Solubility: Chloroform (Slightly), Methanol (Slightly)
• PKA: -3.65±0.10(Predicted)
• Water Solubility: insoluble
• BRN: 108922
• CAS DataBase Reference: 2,6-Dibromopyridine(CAS DataBase Reference)
• NIST Chemistry Reference: 2,6-Dibromopyridine(626-05-1)
• EPA Substance Registry System: 2,6-Dibromopyridine(626-05-1)

Safety Data

• Hazard Codes: Xi,T,T+
• Statements: 36/37/38-25-20/21-52-28-52/53-36/38
• Safety Statements: 26-37/39-45-36/37/39-36-36/37-28-61
• RIDADR: 2811
• WGK Germany: 3
• RTECS: US7883000
• HazardClass: 6.1
• PackingGroup: II
• Hazardous Substances Data: 626-05-1(Hazardous Substances Data)

Usage

Uses

Used in Chemical Synthesis:
2,6-Dibromopyridine is used as a tridentate chelating ligand for the formation of metal complexes. Its ability to bind with metal ions through multiple donor atoms makes it a versatile building block in the synthesis of coordination compounds with potential applications in catalysis, sensing, and materials science.
Used in Pharmaceutical Industry:
In the pharmaceutical industry, 2,6-Dibromopyridine is utilized in the synthesis of macrocycles containing the terpyridine moiety. These macrocyclic compounds have attracted significant interest due to their potential use as drug candidates, particularly in the development of new antibiotics, antitumor agents, and other therapeutic agents.
Used in Organic Synthesis:
2,6-Dibromopyridine is also used as a key intermediate in the production of various organic compounds. For example, it can be converted to 6-bromo-2-methoxypyridine, which can further be used in the synthesis of other pyridine-based compounds with potential applications in various fields, such as agrochemicals, dyes, and pharmaceuticals.

Purification Methods

Purify 2,6-dibromopyridine by steam distillation, then recrystallise it twice from EtOH. It does not form an HgCl2 salt. [den Hertog & Wibaut Recl Trav Chim Pays Bas 51 381 1932, Beilstein 20/5 V 435.]

InChI:InChI=1/C5H3Br2N/c6-4-2-1-3-5(7)8-4/h1-3H

Synthetic route

2,6-dibromopyridin N-oxide (25373-69-7) → 2,6-Dibromopyridine (626-05-1)

pyridine N-oxide (694-59-7) → 2,6-Dibromopyridine (626-05-1)

Conditions	Yield
With carbon tetrabromide; lithium tert-butoxide In m-xylene at 100℃; for 1h; Inert atmosphere;	30%

pyridine (110-86-1) → 2-bromo-pyridine (109-04-6) + 2,6-Dibromopyridine (626-05-1)

Conditions	Yield
With bromine at 500℃; Leiten ueber Bimsstein;
With bromine at 500℃; Leiten ueber Glas;

2,6-dichloropyridine (2402-78-0) → 2,6-Dibromopyridine (626-05-1)

Conditions	Yield
With acetic acid

2-bromo-pyridine (109-04-6) → 2,6-Dibromopyridine (626-05-1)

Conditions	Yield
With bromine at 300℃; Leiten ueber mit Kupfer(I)-bromid impraegnierten Bimsstein;

silver salt of/the/ 2.6-dibromo-isonicotinic acid → 2,6-Dibromopyridine (626-05-1)

Conditions	Yield
at 226℃;

2,6-dibromo-3-aminopyridine (39856-57-0) → 2,6-Dibromopyridine (626-05-1)

Conditions	Yield
With ethanol; sulfuric acid anschliessend Behandeln mit wss. Natriumnitrit-Loesung;

pyridin-3-ylamine (462-08-8) → 2,6-Dibromopyridine (626-05-1)

Conditions	Yield
Multi-step reaction with 2 steps 1: methanol; bromine 2: ethanol; concentrated sulfuric acid / anschliessend Behandeln mit wss. Natriumnitrit-Loesung View Scheme

pyridine (110-86-1) + bromine (7726-95-6) + pumice stone → 2-bromo-pyridine (109-04-6) + 2,6-Dibromopyridine (626-05-1)

Conditions	Yield
at 500℃;

6-bromo-1-methyl-1,2-dihydropyridin-2-one (873383-11-0) + phosphorus tribromide (7789-60-8) + phosphorus pentabromide (7789-69-7) → 2,6-Dibromopyridine (626-05-1)

Conditions	Yield
at 190℃;

2-bromo-pyridine (109-04-6) + bromine (7726-95-6) + copper (I)-bromide → 2,6-Dibromopyridine (626-05-1) + pentabromopyridine (2402-94-0)

Conditions	Yield
at 300℃;

2,6-Dibromopyridine (626-05-1) + carbon monoxide (201230-82-2) + 4-chloro-aniline (106-47-8) → N,N'-bis(4'-chlorophenyl)pyridine-2,6-dicarboxamide (126230-11-3)

Conditions	Yield
With triethylamine; tetrakis(triphenylphosphine) palladium(0) In toluene at 100℃; under 2574.3 Torr; for 8h;	100%

2,6-Dibromopyridine (626-05-1) + trimethylsilylacetylene (1066-54-2) → 2,6-bis(2-(trimethylsilyl)ethynyl)pyridine (75867-44-6)

Conditions	Yield
With copper(l) iodide; tetrakis(triphenylphosphine) palladium(0); diisopropylamine In toluene at 20℃; Sonogashira Cross-Coupling;	100%
With copper(l) iodide; tetrakis(triphenylphosphine) palladium(0); diisopropylamine In tetrahydrofuran at 50℃; for 6h; Inert atmosphere;	98%
With copper(l) iodide; tetrakis(triphenylphosphine) palladium(0); N-ethyl-N,N-diisopropylamine In toluene for 90h; Sonogashira Cross-Coupling; Inert atmosphere; Darkness;	98%

2,6-Dibromopyridine (626-05-1) → 2-bromo-pyridine (109-04-6)

Conditions	Yield
With n-butyllithium; butyl magnesium bromide In toluene at -10℃;	100%
With n-butyllithium; isopropyl alcohol In hexane; dichloromethane 1.) -78 deg C, 1 h, 2.) -78 deg C, 30, min; warm to room temperature;	90%
With n-butyllithium; formaldehyd In tetrahydrofuran at -70 - -40℃;	90%

2,6-Dibromopyridine (626-05-1) + benzylamine (100-46-9) → 2-N-benzylamino-6-bromopyridine (427900-17-2)

Conditions	Yield
at 150℃; for 0.5h; Microwave irradiation;	100%
With potassium fluoride on basic alumina; palladium diacetate; 2,2'-bis-(diphenylphosphino)-1,1'-binaphthyl at 90 - 100℃; for 8h;	90%
at 150℃; for 5h; Autoclave;	48%

2,6-Dibromopyridine (626-05-1) + 4-chlorobenzylamine (104-86-9) → (6-bromopyridin-2-yl)(4-chlorobenzyl)amine (866546-12-5)

Conditions	Yield
at 150℃; for 0.5h; Neat (no solvent); Microwave irradiation;	100%

2,6-Dibromopyridine (626-05-1) + pentanal (110-62-3) → 1-(6-bromo-2-pyridinyl)-1-pentanol (638214-52-5)

Conditions	Yield
Stage #1: 2,6-Dibromopyridine With n-butyllithium In tetrahydrofuran; hexanes at -78℃; for 1h; Stage #2: pentanal In tetrahydrofuran; hexanes at -78℃; for 0.266667h;	100%

2,6-Dibromopyridine (626-05-1) + dinaphthalen-1-ylzinc → 2,6-di(naphthalen-1-yl)pyridine (1256169-52-4)

Conditions	Yield
With dichloro{bis[1-(dicyclohexylphosphanyl)piperidine]}palladium(II) In tetrahydrofuran; 1-methyl-pyrrolidin-2-one at 100℃; for 0.5h; Negishi cross-coupling reaction; In air;	100%

2,6-Dibromopyridine (626-05-1) + benzyl alcohol (100-51-6) → 2-(benzyloxy)-6-bromopyridine (117068-71-0)

Conditions	Yield
With potassium hydroxide; 18-crown-6 ether In toluene for 1h; Heating;	99.9%
Stage #1: benzyl alcohol With sodium hydride In tetrahydrofuran for 0.5h; Stage #2: 2,6-Dibromopyridine In tetrahydrofuran at 20℃; for 18h;	90%
With sodium hydride In N,N-dimethyl-formamide at 0 - 100℃; for 18h;	79%

2,6-Dibromopyridine (626-05-1) + acetonitrile (75-05-8) → 2-(6-bromopyridin-2-yl)acetonitrile (112575-11-8)

Conditions	Yield
Stage #1: acetonitrile With n-butyllithium In tetrahydrofuran; hexane at -78℃; for 0.5h; Stage #2: 2,6-Dibromopyridine In tetrahydrofuran; hexane at -78 - 20℃; for 1.25h;	99%
Stage #1: acetonitrile With n-butyllithium In tetrahydrofuran; hexane at -78℃; for 0.75h; Metallation; Stage #2: 2,6-Dibromopyridine In tetrahydrofuran; hexane at -78 - 20℃; for 2.5h; Alkylation;	91%
With n-butyllithium 1.) hexane, THF,-70 deg C, 1 h, 2.) -70 deg C,1 h; Yield given. Multistep reaction;
Stage #1: acetonitrile With n-butyllithium In tetrahydrofuran; hexane at -78℃; for 0.5h; Stage #2: 2,6-Dibromopyridine In tetrahydrofuran; hexane at -78 - 20℃; for 1.5h;
Stage #1: acetonitrile With n-butyllithium In tetrahydrofuran; hexane at -78℃; for 0.5h; Stage #2: 2,6-Dibromopyridine In tetrahydrofuran; hexane at -78℃; for 0.75h;

2,6-Dibromopyridine (626-05-1) → 2-bromo-6-deuteropyridine (74126-93-5)

Conditions	Yield
Stage #1: 2,6-Dibromopyridine With n-butyllithium In tetrahydrofuran; hexane at -75℃; for 0.25h; Inert atmosphere; Stage #2: With deuteromethanol In tetrahydrofuran; hexane at -75℃; for 1.01667h;	99%
Stage #1: 2,6-Dibromopyridine With isopropylmagnesium chloride In tetrahydrofuran at 20℃; for 2h; Substitution; Stage #2: With water-d2 In tetrahydrofuran at 20℃; for 18h; Substitution;	95%
With n-butyllithium; Isopropanol-d1 In hexane; dichloromethane 1.) -78 deg C, 1 h, 2.) -78 deg C, 30, min; warm to room temperature;	86%
Stage #1: 2,6-Dibromopyridine In tetrahydrofuran at 20℃; for 1h; Stage #2: With water-d2 In tetrahydrofuran for 0.5h;

2,6-Dibromopyridine (626-05-1) + tris((2-phenyl)ethynyl)indium (250643-76-6) → 2,6-bis(2-phenylethynyl)pyridine (83965-72-4)

Conditions	Yield
(1,1'-bis(diphenylphosphino)ferrocene)palladium(II) dichloride In tetrahydrofuran Heating;	99%

2,6-Dibromopyridine (626-05-1) + phenylboronic acid (98-80-6) → 2,6-diphenylpyridine (3558-69-8)

Conditions	Yield
With C37H28N8O*2Cl(1-)*Pd(2+); potassium carbonate In ethanol at 70℃; for 2h; Suzuki-Miyaura Coupling;	99%
With potassium phosphate tribasic trihydrate; trans-[(2-mesitylpy)2PdCl2] In methanol; water at 80℃; for 1h; Suzuki-Miyaura Coupling;	99%
With {2,6-bis[(di-1-piperidinylphosphino)amino]phenyl}palladium(II) chloride; potassium carbonate In 1,4-dioxane; water; butan-1-ol at 100℃; for 2h; Suzuki-Miyaura reaction;	96%

2,6-Dibromopyridine (626-05-1) + 2-Methylphenylboronic acid (16419-60-6) → 2,6-di(2-methylphenyl)pyridine

Conditions	Yield
With potassium phosphate tribasic trihydrate; trans-[(2-mesitylpy)2PdCl2] In methanol; water at 80℃; for 1h; Catalytic behavior; Solvent; Time; Reagent/catalyst; Suzuki-Miyaura Coupling;	99%
With tris(dibenzylideneacetone)dipalladium (0); tri-tert-butyl phosphine In tetrahydrofuran for 16h; Heating;	65%
With tri-tert-butyl phosphine; tris-(dibenzylideneacetone)dipalladium(0) In tetrahydrofuran	65%
With potassium phosphate; dichloro{bis[1-(dicyclohexylphosphanyl)piperidine]}palladium(II) In toluene at 80℃; for 4h; Suzuki-Miyaura cross-coupling reaction; Air;	64%

2,6-Dibromopyridine (626-05-1) + phenylacetylene (536-74-3) → 2,6-bis(2-phenylethynyl)pyridine (83965-72-4)

Conditions	Yield
With C19H16ClNPdS; potassium carbonate In N,N-dimethyl-formamide at 110℃; for 24h; Reagent/catalyst; Sonogashira Cross-Coupling;	99%
With bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; triethylamine In N,N-dimethyl-formamide at 80℃; Inert atmosphere;	96%
With bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; triethylamine In N,N-dimethyl-formamide at 80℃; Inert atmosphere;	96%

2,6-Dibromopyridine (626-05-1) + 3,4,5-Trimethoxyaniline (24313-88-0) → 6-bromo-N-(3,4,5-trimethoxyphenyl)pyridin-2-amine (1130556-36-3)

Conditions	Yield
With potassium hexamethylsilazane In 1,4-dioxane at 20℃; for 1h;	99%
With potassium phosphate In 1,4-dioxane at 25℃; for 0.333333h; metal-free Buchwald-Hartwig amination; Inert atmosphere;	98%

2,6-Dibromopyridine (626-05-1) + N-methylaniline (100-61-8) → N,N'-dimethyl-N,N'-diphenylpyridine-2,6-diamine (1130556-33-0)

Conditions	Yield
With potassium hexamethylsilazane In 1,4-dioxane at 100℃; for 0.5h; metal-free Buchwald-Hartwig amination; Inert atmosphere;	99%

2,6-Dibromopyridine (626-05-1) + 4-(ethoxycarbonyl)phenylzinc iodide (131379-16-3) → diethyl 4,4'-pyridine-2,6-diyldibenzoate (1256169-65-9)

Conditions	Yield
With dichloro{bis[1-(dicyclohexylphosphanyl)piperidine]}palladium(II) In tetrahydrofuran; 1-methyl-pyrrolidin-2-one at 100℃; for 0.5h; Negishi cross-coupling reaction; In air;	99%

2,6-Dibromopyridine (626-05-1) + N-ethyl-N-phenylamine (103-69-5) → 6-bromo-N-ethyl-N-phenylpyridin-2-amine (1309609-43-5)

Conditions	Yield
With potassium hexamethylsilazane In 1,4-dioxane at 20℃; for 0.25h;	99%

2,6-Dibromopyridine (626-05-1) + 4-methylphenylboronic acid (5720-05-8) → 2,6-di-p-tolylpyridine (14435-88-2)

Conditions	Yield
With potassium phosphate tribasic trihydrate; trans-[(2-mesitylpy)2PdCl2] In methanol; water at 80℃; for 1h; Suzuki-Miyaura Coupling;	99%
With [Pd(Cl)κ2-S,N-C6H4CS=N-(4-Py)(PPh3)]; potassium carbonate In toluene at 80℃; for 5h; Suzuki coupling;	82%

2,6-Dibromopyridine (626-05-1) + 4-((tert-butyldimethylsilyl)oxy)-N,N,2,2-tetramethylbutanamide → 1-(6-bromopyridin-2-yl)-4-((tert-butyldimethylsilyl)oxy)-2,2-dimethylbutan-1-one

Conditions	Yield
Stage #1: 4-((tert-butyldimethylsilyl)oxy)-N,N,2,2-tetramethylbutanamide With n-butyllithium In tetrahydrofuran; hexane at -78℃; for 0.5h; Stage #2: 2,6-Dibromopyridine In tetrahydrofuran; hexane at -78 - 20℃; for 1h;	99%

piperidine (110-89-4) + 2,6-Dibromopyridine (626-05-1) → 2-bromo-6-(piperidin-1-yl)pyridine (24255-97-8)

Conditions	Yield
With potassium phosphate In 1,4-dioxane at 100℃; for 7h;	98%
With copper(l) iodide; potassium carbonate at 50℃; for 1h;	88%
With potassium phosphate In 1,4-dioxane at 105℃; for 10h; Inert atmosphere;	88%

2,6-Dibromopyridine (626-05-1) + N,N-dimethyl-formamide (68-12-2, 33513-42-7) → 2-bromo-6-(hydroxymethyl)pyridine (33674-96-3)

Conditions	Yield
Stage #1: 2,6-Dibromopyridine; N,N-dimethyl-formamide With n-butyllithium Stage #2: With sodium tetrahydroborate	98%
Stage #1: 2,6-Dibromopyridine With n-butyllithium In tetrahydrofuran; hexane at -70℃; for 0.25h; Inert atmosphere; Stage #2: N,N-dimethyl-formamide In tetrahydrofuran; hexane at -78℃; for 0.25h; Further stages;	92%
Stage #1: 2,6-Dibromopyridine With n-butyllithium In tetrahydrofuran; light petroleum at -78℃; for 3.16667h; Inert atmosphere; Stage #2: N,N-dimethyl-formamide In tetrahydrofuran; light petroleum at -78℃; Inert atmosphere; Stage #3: With sodium tetrahydroborate In tetrahydrofuran; methanol; light petroleum; acetic acid at 20℃; Inert atmosphere;	82%

2,6-Dibromopyridine (626-05-1) + (1R)-fenchone (7787-20-4) → (1R,2R,4S)-2-(6-bromopyridine-2-yl)-1,3,3-trimethylbicyclo[2.2.1]heptan-2-ol (256428-16-7)

Conditions	Yield
With n-butyllithium In tetrahydrofuran; hexane at -78℃; diastereoselective reaction;	98%
Stage #1: 2,6-Dibromopyridine With n-butyllithium In diethyl ether; hexane at -78℃; for 0.5h; Stage #2: (1R)-fenchone In diethyl ether; hexane Further stages.;	90%
Stage #1: 2,6-Dibromopyridine With n-butyllithium In diethyl ether; hexane at -78 - -45℃; for 0.25h; Metallation; Stage #2: (1R)-fenchone In diethyl ether; hexane at -78 - 20℃; for 3.5h; Addition;	48%

2,6-Dibromopyridine (626-05-1) + 4-methoxy-2,6-dimethylphenylboronic acid (361543-99-9) → 2,6-bis-(4-methoxy-2,6-dimethyl-phenyl)-isonicotinic acid methyl ester

Conditions	Yield
With tri-tert-butyl phosphine; tris-(dibenzylideneacetone)dipalladium(0) In tetrahydrofuran	98%

2,6-Dibromopyridine (626-05-1) + C9H15N3 (155511-82-3) → C14H17BrN4

Conditions	Yield
With 1,8-diazabicyclo[5.4.0]undec-7-ene In DMF (N,N-dimethyl-formamide) at 100℃; for 9h;	98%

2,6-Dibromopyridine (626-05-1) + acetone (67-64-1) → 2-(6-bromopyridin-2- yl)propan-2-ol (638218-78-7)

Conditions	Yield
Stage #1: 2,6-Dibromopyridine With n-butyllithium In tetrahydrofuran; hexane at -76 - -60℃; Stage #2: acetone In tetrahydrofuran; hexane at 20℃; Cooling with dry ice; Stage #3: With ammonium chloride In tetrahydrofuran; hexane; water	98%
With n-butyllithium In tetrahydrofuran; hexane at -76 - 20℃; for 1.25h; Cooling with ice;	94.3%
Stage #1: 2,6-Dibromopyridine With n-butyllithium In tetrahydrofuran; hexane at -76℃; for 0.75h; Cooling with acetone-dry ice; Stage #2: acetone In tetrahydrofuran; hexane at 20℃; for 1.25h; Cooling with acetone-dry ice;	94%

2,6-Dibromopyridine (626-05-1) + 2,6-diisopropylbenzenamine (24544-04-5) → N-[2,6-bis(1-methylethyl)phenyl]-6-bromopyridin-2-amine (1127647-91-9)

Conditions	Yield
With potassium phosphate In 1,4-dioxane at 25℃; for 0.333333h; metal-free Buchwald-Hartwig amination; Inert atmosphere;	98%
With potassium hexamethylsilazane In 1,4-dioxane at 20℃; for 1h;	78%
With 2,2,6,6-tetramethyl-piperidine at 230℃; for 6h; Sealed tube;	20%

2,6-Dibromopyridine (626-05-1) + N-methylaniline (100-61-8) → 6-bromo-N-methyl-N-phenylpyridin-2-amine (25194-53-0)

Conditions	Yield
With potassium phosphate In 1,4-dioxane at 25℃; for 0.333333h; metal-free Buchwald-Hartwig amination; Inert atmosphere;	98%
With potassium hexamethylsilazane In 1,4-dioxane at 20℃; for 0.5h;	98%

2,6-Dibromopyridine (626-05-1) + 2-(methylamino)-6-bromopyridine (89026-79-9) → N-methyl-bis(6-bromopyridin-2-yl)amine (1032745-39-3)

Conditions	Yield
Stage #1: 2-bromo-6-(methylamino)pyridine With sodium hydride In tetrahydrofuran at 20℃; Reflux; Stage #2: 2,6-Dibromopyridine In tetrahydrofuran for 6h; Reflux;	98%

Upstream product

• 110-86-1 pyridine 
• 109-04-6 2-bromo-pyridine 
• 39856-57-0 2,6-dibromo-3-aminopyridine 
• 25373-69-7 2,6-dibromopyridin N-oxide 
• 873383-11-0 6-bromo-1-methyl-1,2-dihydropyridin-2-one 
• 7789-60-8 phosphorus tribromide 
• 7789-69-7 phosphorus pentabromide 
• 7726-95-6 bromine 
• 462-08-8 pyridin-3-ylamine 
• 2402-78-0 2,6-dichloropyridine 
• 694-59-7 pyridine N-oxide 

Downstream Products

• 24255-97-8 2-bromo-6-(piperidin-1-yl)pyridine 
• 83247-00-1 2-bromo-6-phenoxypyridine 
• 107432-29-1 2,6-diphenoxypyridine 
• 856850-57-2 6-bromo-N,N-diethylpyridin-2-amine 
• 873383-11-0 6-bromo-1-methyl-1,2-dihydropyridin-2-one 
• 25373-69-7 2,6-dibromopyridin N-oxide 
• 141-86-6 2.6-diaminopyridine 
• 19798-81-3 2-Amino-6-bromopyridine 
• 27992-32-1 6-bromo-2-hydroxypyridine 
• 4645-11-8 6-ethoxy-2-bromo-pyridine 
• 2402-92-8 2,3,6-tribromopyridine 
• 2766-64-5 2,3,5,6-tetrabromopyridine 
• 31796-72-2 phenyl(2-pyridinyl)methanol 
• 853916-14-0 2,6-bis-(α-hydroxy-benzyl)-pyridine 

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A new convenient method of deoxygenation of heteroaromatic N-oxides is described. Ruthenium porphyrin was used as a catalyst and this method expressed high yields for o-substituted pyridine N-oxides, quinoline N-oxide derivatives, acridine N-oxide, etc. under mild conditions. Moreover, nitro-, benzyloxy-, and ketone carbonyl groups, which can be affected by the usual deoxygenation methods such as catalytic hydrogenation or borane reduction, were retained.

Titanium(0) Reagents; 2. A Selective and Efficient Deoxygenation of Halogen Containing Heteroaromatic N-Oxides

Following successful reductions of unfunctionalized heteroaromatic N-oxides by titanium(0), we applied this method to halogenated aromatic N-oxides to give the deoxygenated halogeno derivatives in 90-95percent yield.

Continuous process for the production of polybromopyridine compounds

A continuous process for producing a polybromopyridine compound comprises admixing a polychloropyridine compound with an anhydrous water soluble solvent in a first reaction zone to form a solution of the polychloropyridine compound. Hydrogen bromide gas is introduced into the solution while maintaining the temperature in the range of from about 70° to about 140° C. to produce a solution of the polybromopyridine compound. The solution is cooled to a temperature in the range of from about 5° to about 35° C. to precipitate the polybromopyridine compound from the anhydrous solvent. The polybromopyridine compound is separated from the anhydrous solvent and the anhydrous solvent is returned to the first reaction zone. Polybromopyridine compounds of increased purity are produced in a process having reduced material, energy and operating costs. The process does not require the use of water or other co-solvents nor the distillation of the reaction product mixture.

Process for the manufacture of bromopyridines

A novel process for the preparation of 2,4-dibromo-, 2,6-dibromo- and 2,4,6-tribromopyridines, and the new bromopyridines to be obtained therewith, are disclosed. The novel process comprises treating 2,4-dichloro-, 2,6-dichloro- and 2,4,6-trichloropyridines, in an anhydrous organic medium, with gaseous HBr at temperatures between 80° and 130°C, said process being both simple and economical.