137-43-9

Basic information

• Product Name: Bromocyclopentane
• Synonyms: CYCLOPENTYL BROMIDE;BROMOCYCLOPENTANE;AKOS BBS-00004279;Cyclopentane Bromide;Bromocyclopentane,98%;1-Bromocyclopentane;BROMOCYCLOPENTANE, STAB.;CYCLOPENTYL BROMIDE, 98+%
• CAS NO: 137-43-9
• Molecular Formula: C₅H₉Br
• Molecular Weight: 149.03
• EINECS: 205-294-6
• Product Categories: Pharmaceutical Intermediates;CHLORO ALKANE COMPOUNDS;Pyridines ,Halogenated Heterocycles
• Mol File: 137-43-9.mol
• Article Data: 36

Chemical Properties

• Boiling Point: 137-139 °C(lit.)
• Flash Point: 95 °F
• Appearance: Clear yellow to light brown/Liquid
• Density: 1.39 g/mL at 25 °C(lit.)
• Vapor Pressure: 9.73mmHg at 25°C
• Refractive Index: n20/D 1.4881(lit.)
• Storage Temp.: Store at R.T.
• Water Solubility: Immiscible with water.
• Stability: Stable. Flammable. Incompatible with strong oxidizing agents, strong bases.
• BRN: 1209256
• CAS DataBase Reference: Bromocyclopentane(CAS DataBase Reference)
• NIST Chemistry Reference: Bromocyclopentane(137-43-9)
• EPA Substance Registry System: Bromocyclopentane(137-43-9)

Safety Data

• Statements: 10
• Safety Statements: 23-24/25-16
• RIDADR: UN 1993 3/PG 3
• WGK Germany: 3
• F: 8
• TSCA: Yes
• HazardClass: 3
• PackingGroup: III
• Hazardous Substances Data: 137-43-9(Hazardous Substances Data)

Usage

Chemical Properties

Bromocyclopentane is a colorless to light yellow liquid at standard temperature and pressure.It has an aroma similar to camphor. It turns brown after a long time. Soluble in ethanol, ether, insoluble in water. Halocyclopentanes can be prepared by reacting the corresponding alcohols with thionyl halides, phosphorus trihalides or hydrohalic acids.

Uses

Bromocyclopentane is a precursor used in the preparation of cyclopentene and cyclopentanol. It is a fatty bromide, which is used as a solvent. It is used as an intermediate for the preparation of surfactant and pharmaceuticals and other organic compounds. It is also used in the production of the medicine cyclopentathiazide.

Preparation

Bromocyclopentane is synthesized by bromination of cyclopentanol: cyclopentanol is mixed with hydrobromic acid and heated to about 170°C refluxed for 6-8h. Then distilled with water steam, the oil layer is washed with 5% sodium carbonate, then dried, filtered, fractionated and collected 136-139°C fraction is the finished product. Another method is by the reaction of cyclopentanol and phosphorus tribromide: the cyclopentanol is cooled to 0 ℃, add the newly evaporated phosphorus tribromide drop by drop, add it all at 0-5 ℃, stir for 2h, and leave it at room temperature overnight. Add water and stratify, take the oil layer water distillation. Distillate stratification, the oil layer was washed with 10% sodium bicarbonate solution, dried with anhydrous calcium chloride, filtration, filtrate distillation, collect 134-141 ℃ fraction that is bromocyclopentane.

Reactions

Bromocyclopentane is reacted with magnesium turnings in dry tetrahydrofuran making cyclopentyl Grignard reagent, a main precursor in the synthesis of Ketamine.Bromocyclopentane (22.0 g, 0.15 mol) was added to a soln of NaNO2 (18 g, 0.26 mol) in dry DMSO (100 mL) at 15°C and the mixture was stirred at this temperature for 3 h. The mixture was poured into ice water (250 mL) and extracted with petroleum ether (bp 35-37°C; 4 × 50 mL). The combined organic extracts were washed with H2O (4× 50 mL), dried (MgSO4), and concentrated under reduced pressure. The residue was distilled to give Nitrocyclopentane; yield: 9.9 g (58%); bp 62°C/8 Torr; nD/20 1.4538.Synthesis of Nitrocyclopentane

Synthesis Reference(s)

The Journal of Organic Chemistry, 54, p. 1463, 1989 DOI: 10.1021/jo00267a047

InChI:InChI=1/C5H9Br/c6-5-3-1-2-4-5/h5H,1-4H2

Synthetic route

Cyclopentane (287-92-3) → Cyclopentyl bromide (137-43-9)

Conditions	Yield
With bromine; aluminium trichloride; Acetyl bromide In pentane at 0℃; for 1.83333h;	100%
With bromine; aluminium trichloride; Acetyl bromide In pentane at 0℃; for 1.83333h; Product distribution; ionic bromination of other cycloalkanes and n-alkanes with various catalysts and at different temperatures;	100%
With bromine; sodium t-butanolate In cyclohexane Heating;	100%

5-Cyclopentyloxy-thianthren-5-ium; perchlorate → Cyclopentyl bromide (137-43-9) + thianthrene-5-oxide (2362-50-7) + cyclopentene (142-29-0) + Thianthrene (92-85-3)

Conditions	Yield
With 18-crown-6 ether; potassium bromide Product distribution; Substitution; elimination;	A 89% B 100% C 1.5% D 3.5%

Cyclopentanol (96-41-3) → Cyclopentyl bromide (137-43-9)

Conditions	Yield
With t-butyl bromide; n-pentylmethylimidazolium bromide for 2h; sonication;	82%
With sulfuric acid; hydrogen bromide at 100℃;
With hydrogen bromide at 100℃;

Cyclopentane (287-92-3) → Cyclopentyl bromide (137-43-9) + Cyclopentanol (96-41-3)

Conditions	Yield
With [FeIV(1,1-di(pyridin-2-yl)-N,N-bis(quinolin-2-ylmethyl)methanamine)(O)]2+; [FeII(1,1-di(pyridin-2-yl)-N,N-bis(quinolin-2-ylmethyl)methanamine)(Br)]Br In acetonitrile at 25℃; for 0.5h; Inert atmosphere; Glovebox;	A 52% B n/a

cyclobutanemethanol (4415-82-1) → Cyclopentyl bromide (137-43-9)

Conditions	Yield
With hydrogen bromide

Bromotrichloromethane (75-62-7) + bicyclo[2.1.0]pentane (185-94-4) → Cyclopentyl bromide (137-43-9) + cyclopent-3-enyl bromide (1781-66-4) + trans-1-bromo-2-(trichloromethyl)cyclopentane (17827-32-6, 19640-06-3) + trans-1,2-dibromocyclopentane (10230-26-9) + trans-1-bromo-2-chlorocyclopentane (14376-82-0, 37722-39-7, 89180-35-8) + cis-1-bromo2-chlorocyclopentane (14376-82-0, 37722-39-7, 89180-35-8)

Conditions	Yield
for 4h; Product distribution; Mechanism; Ambient temperature; Irradiation; Effect of added t-butyl hypochlorite;

Cyclopentane (287-92-3) → Succinimide (123-56-8) + Cyclopentyl bromide (137-43-9) + 1,2-dibromopentane (3234-49-9) + 3-bromopropanoyl isocyanate (18926-24-4)

Conditions	Yield
With N-Bromosuccinimide; cyclohexane In acetonitrile at 23℃; for 16h; Product distribution; Mechanism; Irradiation; Effect of solvent on the Relative Rates of Bromination; Effect of Added Bromine; Effect of Added Olefine (C2H4);

Cyclopentane (287-92-3) → Cyclopentyl bromide (137-43-9) + 1,2-dibromo-cyclopentane (29974-65-0)

Conditions	Yield
With N-Bromosuccinimide; bromine In dichloromethane; cyclohexane at 15℃; Product distribution; Mechanism; Irradiation; relative reactivity; other cycloalkanes; other bromination agents; var temp.;	A 37.6 % Chromat. B 13.7 % Chromat.
With hydrogen bromide; dihydrogen peroxide In water at 50℃; for 6h; Irradiation;	A 64.3 %Spectr. B 15 %Spectr.

cyclopentyl iodide (1556-18-9) → Cyclopentyl bromide (137-43-9)

Conditions	Yield
With iodobenzene; tetrabutylammomium bromide In tetrachloromethane; acetonitrile at 25℃; Rate constant;

bicyclo[2.1.0]pentane (185-94-4) → Cyclopentyl bromide (137-43-9) + cis-1,3-dibromocyclopentane (68479-47-0) + trans-1,2-dibromocyclopentane (10230-26-9) + trans-1,3-dibromocyclopentane (68479-48-1)

Conditions	Yield
With bromine In tetrachloromethane at 0℃; Product distribution; Mechanism;

cyclopentyldiphenylbismutane (96449-49-9) → Cyclopentyl bromide (137-43-9) + bromobenzene (108-86-1)

Conditions	Yield
With bromine In dichloromethane -70 deg C to r.t.;	A 67 % Chromat. B 19 % Chromat.

cyclopentene (142-29-0) → Cyclopentyl bromide (137-43-9)

Conditions	Yield
With borane; bromine; sodium methylate 1.) THF, 2.) 20-25 deg C, MeOH; Yield given. Multistep reaction;

silver salt of/the/ cyclopentanecarboxylic acid → Cyclopentyl bromide (137-43-9)

Conditions	Yield
With chloroform; bromine

cyclobutanemethanol (4415-82-1) + hydrogen bromide (10035-10-6, 12258-64-9) → Cyclopentyl bromide (137-43-9)

Conditions	Yield
at 100℃; im Rohr;

butyl-cyclopentyl ether (98954-98-4) + hydrogen bromide (10035-10-6, 12258-64-9) → 1-bromo-butane (109-65-9) + Cyclopentyl bromide (137-43-9)

Conditions	Yield
at 26℃;

cyclopenta-1,3-diene (542-92-7) → Cyclopentyl bromide (137-43-9) + cyclopent-3-enyl bromide (1781-66-4)

Conditions	Yield
Stage #1: cyclopenta-1,3-diene With borane-THF In tetrahydrofuran at 20℃; for 2h; Stage #2: With sodium hydroxide; dihydrogen peroxide In diethyl ether for 0.5h; Stage #3: With phosphorus tribromide In pentane for 12h; Heating; Title compound not separated from byproducts;

cyclopentylpentaaquochromium(III) (84559-49-9) → Cyclopentyl bromide (137-43-9) + chromium(III) hexahydrate cation (14873-01-9)

Conditions	Yield
With bromine In water Kinetics; byproducts: Br(1-); reaction complex with bromine at 25°C;

Cyclopentane (287-92-3) → Cyclopentyl bromide (137-43-9) + trans-1,2-dibromocyclopentane (10230-26-9)

Conditions	Yield
With bromine In water at 20℃; for 0.316667h; Flow reactor; UV-irradiation; Overall yield = 92 %Chromat.;

cyclopentyl methyl ether (5614-37-9) → Cyclopentyl bromide (137-43-9)

Conditions	Yield
With boron trichloride; boron tribromide In dichloromethane at -78 - 20℃; for 16h; Inert atmosphere; regioselective reaction;

Cyclopentyl bromide (137-43-9) → cyclopentyl azide (33670-50-7)

Conditions	Yield
With sodium azide In dimethyl sulfoxide	100%
With sodium azide In dimethyl sulfoxide at 25℃; for 9h;	98%
With sodium azide In dimethyl sulfoxide	94%

Cyclopentyl bromide (137-43-9) + 4-Hydroxyacetophenone (99-93-4) → 1-(4-cyclopentyloxy-phenyl)-ethanone (857563-36-1)

Conditions	Yield
With caesium carbonate In acetonitrile at 80℃; for 3h;	100%
With sodium hydroxide

Cyclopentyl bromide (137-43-9) + 5-bromo-2-methoxyphenol (37942-01-1) → 4-bromo-2-cyclopentyloxyanisole (138509-45-2)

Conditions	Yield
With potassium carbonate In acetone for 24h; Heating;	100%
With potassium carbonate In N,N-dimethyl-formamide at 65℃; for 10h;	99%
With potassium carbonate In N,N-dimethyl-formamide at 50℃; for 20h;	93%

Cyclopentyl bromide (137-43-9) + N-ethylidenecyclohexylamine (113832-57-8, 1193-93-7) + 4-t-butoxy-3-methyl-2,5-difluoropyridine (169749-84-2) → (4-tert-Butoxy-5-fluoro-3-methyl-pyridin-2-yl)-cyclopentyl-acetaldehyde

Conditions	Yield
With lithium diisopropyl amide at 0 - 25℃;	100%

Cyclopentyl bromide (137-43-9) + 4-difluoromethoxy-3-hydroxybenzaldehyde (151103-08-1) → 3-Cyclopentyloxy-4-difluoromethoxybenzaldehyde (153587-14-5)

Conditions	Yield
With potassium carbonate In DMF (N,N-dimethyl-formamide)	100%
With potassium carbonate In N-methyl-acetamide	89%
With potassium carbonate; potassium iodide In N,N-dimethyl-formamide at 65℃; for 22h;	87%

Cyclopentyl bromide (137-43-9) + 4-azatricyclo<4.3.1.1.3,8>undecan-5-one (22607-75-6) → 4-(cyclopentyl)-4-azatricyclo[4.3.1.13,8]undecan-5-one (404352-65-4)

Conditions	Yield
With 18-crown-6 ether; sodium hydride at 80℃; for 120h;	100%

Cyclopentyl bromide (137-43-9) + salicylaldehyde (90-02-8) → 2-(cyclopentyloxy)benzaldehyde

Conditions	Yield
With 18-crown-6 ether; potassium carbonate In acetone for 24h; Inert atmosphere; Reflux;	100%
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 4h; Inert atmosphere; Sealed vial;
With sodium hydride In N,N-dimethyl-formamide at 10 - 35℃; for 2h;

Cyclopentyl bromide (137-43-9) + methyl 3-hydroxy-4-nitrobenzoate (713-52-0) → methyl 3-cyclopentyloxy-4-nitrobenzoate

Conditions	Yield
With sodium chloride; potassium carbonate In N,N-dimethyl-formamide	100%
With potassium carbonate In N,N-dimethyl-formamide at 65℃; for 4h;

Cyclopentyl bromide (137-43-9) + 1-iodo-butane (542-69-8) → 2-butoxy-1-methoxy-4-nitro-benzene (205067-45-4)

Conditions	Yield
	100%

Cyclopentyl bromide (137-43-9) + 5-Bromo-2-hydroxyacetophenone (1450-75-5) → 1-(5-bromo-2-cyclopentyloxyphenyl)ethanone (1092496-74-6)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 60℃; for 13.5h;	100%

Cyclopentyl bromide (137-43-9) + 3-(tert-butoxycarbonyl)-6-isopropyl-9-(3-methoxypropoxy)-2-oxo-6,7-dihydro-2H-pyrido[2,1-a]isoquinoline-10-carboxylic acid → 3-tert-butyl 10-cyclopentyl 6-isopropyl-9-(3-methoxypropoxy)-2-oxo-6,7-dihydro-2H-pyrido[2,1-a]isoquinoline-3,10-dicarboxylate

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 50℃; for 12h;	100%

Cyclopentyl bromide (137-43-9) + 5-nitroguaiacol (636-93-1) → 1-cyclopentyloxy-2-methoxy-5-nitrobenzene (154464-25-2)

Conditions	Yield
With potassium carbonate In DMF (N,N-dimethyl-formamide) at 100℃; for 10h;	99.6%
With potassium carbonate In acetone for 24h; Heating;	98%
With potassium carbonate In acetonitrile at 90℃;	76.9%

isovanillin (621-59-0) + Cyclopentyl bromide (137-43-9) → 3-cyclopentyloxy-4-methoxybenzylaldehyde (67387-76-2)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 65℃; for 16h;	99%
With potassium carbonate In N,N-dimethyl-formamide at 60℃; for 12h;	97%
With potassium carbonate In N,N-dimethyl-formamide at 100℃;	97%

NH-pyrazole (288-13-1) + Cyclopentyl bromide (137-43-9) → 1-cyclopentyl-1H-pyrazole

Conditions	Yield
With sodium hydrogencarbonate at 120℃; for 12h;	99%

Cyclopentyl bromide (137-43-9) → cyclopentanone (120-92-3)

Conditions	Yield
With oxygen; kieselguhr; copper(l) chloride In hexane for 2.5h; Oxidation; Heating;	99%

Cyclopentyl bromide (137-43-9) + N-hydroxyphthalimide (524-38-9) → 2-(cyclopentyloxy)-1H-isoindole-1,3(2H)-dione (54224-24-7)

Conditions	Yield
Stage #1: N-hydroxyphthalimide With potassium carbonate In dimethyl sulfoxide at 20℃; for 0.0833333h; Stage #2: Cyclopentyl bromide In dimethyl sulfoxide at 80℃; for 3h;	99%
With 1,8-diazabicyclo[5.4.0]undec-7-ene In N,N-dimethyl-formamide at 80℃; for 2h;	87%
Stage #1: N-hydroxyphthalimide With potassium carbonate In dimethyl sulfoxide at 25℃; for 0.0833333h; Stage #2: Cyclopentyl bromide In dimethyl sulfoxide at 80℃; for 3h;	85%

Cyclopentyl bromide (137-43-9) + benzene (71-43-2) → 1,3,5-tricyclopentylbenzene (18970-51-9)

Conditions	Yield
With aluminum (III) chloride at -40 - 20℃; Inert atmosphere;	99%
With aluminum (III) chloride In dichloromethane at 0℃; for 2h; Friedel-Crafts Alkylation; Inert atmosphere;	90%
With aluminum (III) chloride In dichloromethane at 0 - 20℃; for 2h; Inert atmosphere;
With aluminum (III) chloride at -40 - 20℃; Inert atmosphere;
With aluminum (III) chloride at -40 - 20℃; Inert atmosphere;

Cyclopentyl bromide (137-43-9) + 3-(1-methyl-1H-indol-3-yl)-4-(propylamino)-1H-pyrrole-2,5-dione → 1-cyclopentyl-3-(1-methyl-1H-indol-3-yl)-4-(propylamino)-1H-pyrrole-2,5-dione

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 50℃; for 24h;	99%

4-hydroxy-3-ethoxybenzaldehyde (121-32-4) + Cyclopentyl bromide (137-43-9) → 3-ethoxy-4-cyclopentoxybenzaldehyde

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 65℃; for 15h;	99%

Cyclopentyl bromide (137-43-9) + 2-(3,4,5-trimethoxybenzoyl)-4-phenyl-1H-imidazole (1429621-76-0) → C24H26N2O4 (1429621-96-4)

Conditions	Yield
With potassium carbonate In acetonitrile Reflux;	98.3%

Cyclopentyl bromide (137-43-9) + aniline (62-53-3) → N-cyclopentylaniline (40649-26-1)

Conditions	Yield
With potassium iodide In acetonitrile at 170℃; under 4875.39 Torr; for 0.166667h; microwave irradiation;	98%

Cyclopentyl bromide (137-43-9) + vanillin (121-33-5) → 4-cyclopentyloxy-3-methoxy-benzaldehyde (197573-17-4)

Conditions	Yield
With potassium carbonate In ethanol for 16h; Reflux;	98%
With tetrabutylammomium bromide; potassium carbonate In tetrahydrofuran; water; ethyl acetate	97%
With potassium carbonate In N,N-dimethyl-formamide at 65℃; for 8h; Inert atmosphere;	97%

Cyclopentyl bromide (137-43-9) + 4-benzyloxy-3-hydroxy-benzaldehyde (4049-39-2) → 3-cyclopentoxy-4-(benzyloxy)benzaldehyde (159783-04-7)

Conditions	Yield
With potassium carbonate In DMF (N,N-dimethyl-formamide) at 20℃;	98%
With potassium carbonate In N-methyl-acetamide; diethyl ether; water
With potassium carbonate In N-methyl-acetamide; diethyl ether; water

Cyclopentyl bromide (137-43-9) + 4-bromo-2-chlorophenol (3964-56-5) → 4-bromo-2-chloro-1-(cyclopentyloxy)benzene (1310949-91-7)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 20℃; for 96h;	98%
With caesium carbonate In N,N-dimethyl acetamide at 150℃; for 16h;
With caesium carbonate In 1-methyl-pyrrolidin-2-one at 145 - 155℃; for 24h;

6-chloro-2-hydroxypyridine (16879-02-0) + Cyclopentyl bromide (137-43-9) → 2-chloro-6-(cyclopentoxy)pyridine

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 24h;	98%
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 24h;	98%

Cyclopentyl bromide (137-43-9) + N-(2-fluorophenyl)-9-isopropyl-9H-purin-6-amine → N-(2-cyclopentyl-6-fluorophenyl)-9-isopropyl-9H-purin-6-amine

Conditions	Yield
With (1,2-dimethoxyethane)dichloronickel(II); N,N'-di-tert-butylethylenediamine; lithium tert-butoxide In 1,4-dioxane at 120℃; for 16h; Inert atmosphere; Schlenk technique;	98%

Cyclopentyl bromide (137-43-9) + 6-bromo-2-(2,5-dimethyl-1H-pyrrol-1-yl)-4-methylquinazolin-8-ol → 6-bromo-8-(cyclopentyloxy)-2-(2,5-dimethyl-1H-pyrrol-1-yl)-4-methylquinazoline

Conditions	Yield
With potassium carbonate In acetonitrile at 60℃; Sealed tube;	98%

Cyclopentyl bromide (137-43-9) + zinc(II) chloride (7646-85-7) → cyclopentylzinc chloride

Conditions	Yield
Stage #1: Cyclopentyl bromide With magnesium; lithium chloride In tetrahydrofuran at 25℃; Inert atmosphere; Schlenk technique; Stage #2: zinc(II) chloride In tetrahydrofuran at 0 - 25℃; for 0.25h; Inert atmosphere; Schlenk technique;	98%

Upstream product

• 96-41-3 Cyclopentanol 
• 4415-82-1 cyclobutanemethanol 
• 75-62-7 Bromotrichloromethane 
• 185-94-4 bicyclo[2.1.0]pentane 
• 287-92-3 Cyclopentane 
• 1556-18-9 cyclopentyl iodide 
• 96449-49-9 cyclopentyldiphenylbismutane 
• 142-29-0 cyclopentene 
• 10035-10-6 hydrogen bromide 
• 98954-98-4 butyl-cyclopentyl ether 
• 542-92-7 cyclopenta-1,3-diene 
• 84559-49-9 cyclopentylpentaaquochromium(III) 
• 5614-37-9 cyclopentyl methyl ether 

Downstream Products

• 30762-02-8 4-(cyclopentyloxy)benzoic acid 
• 7133-21-3 cyclohexyl-cyclopentyl sulfide 
• 4479-29-2 Hydroxy-cyclopentyl-diphenyl-methan 
• 7133-14-4 cyclopentyl-propyl sulfide 
• 26306-40-1 cyclopentyl ethyl ether 
• 142-29-0 cyclopentene 
• 7133-17-7 Isobutyl-cyclopentyl-sulfid 
• 7133-16-6 cyclopentyl n-butyl sulfide 
• 7133-20-2 Amyl-cyclohexyl-sulfid 
• 857638-69-8 cyclopentyl-[2-(4-methoxy-phenyl)-1-methyl-ethyl]-amine 
• 33186-68-4 cyclopentyl phenyl ether 
• 4254-02-8 cyclopentanecarbonitrile 
• 5614-37-9 cyclopentyl methyl ether 
• 7133-13-3 cyclopentyl ethyl sulfide 

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Molecular structure and pseudorotational motion of Bromocyclopentane (cas 137-43-9) as determined by gas-phase electron diffraction10/01/2019

The molecular structure and pseudorotational motion of bromocyclopentane has been studied at a nozzle temperature of 333K. A pseudorotational potential function of the form V(φ)=(V1/2)(1+cosφ)+(V2/2)(1+cos2φ), where φ is the phase angle, and V1=0.74(40)kcal/mol and V2=0.42(85)kcal/mol gave t...detailed

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