76-04-0

Basic information

• Product Name: Chlorodifluoroacetic acid
• Synonyms: DIFLUOROCHLOROACETIC ACID;CHLORODIFLUOROACETIC ACID;2-chloro-2,2-difluoroacetic acid;RARECHEM AL BO 1535;Aceticacid,chlorodifluoro-;chlorodifluoro-aceticaci;CDFA;Chlorodifluoroaceticacid98%
• CAS NO: 76-04-0
• Molecular Formula: C2HClF2O2
• Molecular Weight: 130.48
• EINECS: 200-928-8
• Product Categories: Pharmaceutical Intermediates;Fluorinated Building Blocks;Fluorinating Reagents & Building Blocks for Fluorinated Biochemical Compounds;Synthetic Organic Chemistry;Chemical Synthesis;Organic Acids;Synthetic Reagents
• Mol File: 76-04-0.mol
• Article Data: 11

Chemical Properties

• Melting Point: 20-23 °C(lit.)
• Boiling Point: 122 °C(lit.)
• Flash Point: 121-122°C
• Appearance: clear colorless to pale brown liquid after melting
• Density: 1.54 g/mL at 25 °C(lit.)
• Vapor Pressure: 10.3mmHg at 25°C
• Refractive Index: n20/D 1.355(lit.)
• Storage Temp.: Inert atmosphere,Room Temperature
• PKA: pK1: 0.46 (25°C)
• Water Solubility: soluble
• Sensitive: Lachrymatory
• BRN: 956625
• CAS DataBase Reference: Chlorodifluoroacetic acid(CAS DataBase Reference)
• NIST Chemistry Reference: Chlorodifluoroacetic acid(76-04-0)
• EPA Substance Registry System: Chlorodifluoroacetic acid(76-04-0)

Safety Data

• Hazard Codes: C
• Statements: 35
• Safety Statements: 26-36/37/39-45
• RIDADR: UN 3261 8/PG 2
• WGK Germany: 3
• F: 19
• TSCA: T
• HazardClass: 8
• PackingGroup: II
• Hazardous Substances Data: 76-04-0(Hazardous Substances Data)

Usage

Chemical Properties

CLEAR COLORLESS TO PALE BROWN LIQUID AFTER MELTING

Uses

It is employed as a starting material for generating difluorocarbene. It is also used as a pharmaceutical and agrochemicals intermediate.

InChI:InChI=1/C2HClF2O2/c3-2(4,5)1(6)7/h(H,6,7)/p-1

Synthetic route

ethyl 2-chloro-2,2-difluoroacetate (383-62-0) → carbon monoxide (201230-82-2) + 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With oxygen; chlorine at 24.84℃; under 760.051 Torr; Kinetics; Temperature; Irradiation;	A 34% B 88%

1,1-difluorotetrachloroethane (76-11-9) → 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With ammonium peroxydisulfate; sodium formate In N,N-dimethyl-formamide at 30℃; for 4h;	66.5%

ethyl 2-chloro-2,2-difluoroacetate (383-62-0) → Difluoroacetic acid (381-73-7) + ethyl difluoroacetate (454-31-9) + 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With ethanol; zinc for 1 - 3h; Product distribution / selectivity; Heating / reflux;	A 9.7% B 61.6% C 0.4%

1,1,2-Trichloro-1,2,2-trifluoroethane (76-13-1) → 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With ammonium peroxydisulfate; sodium formate In N,N-dimethyl-formamide at 20℃; for 10h;	55.6%

sodium 2-chloro-1,1,2,2-tetrafluoroethanesulfinate (89740-32-9) + allyl bromide (106-95-6) → 1,1,2,2-tetrafluoro-1-bromo-2-chloroethane (354-53-0) + 5-chloro-4,4,5,5-tetrafluoro-1-pentene (103780-92-3) + 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With ammonium peroxydisulfate In N,N-dimethyl-formamide at 40℃; for 4h;	A 22% B 53% C 14%

metyhyl chlorodifluoroacetate (1514-87-0) → carbon monoxide (201230-82-2) + formic difluorochloroacetic anhydride + 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With oxygen; chlorine at 24.84℃; under 760.051 Torr; Kinetics; Temperature; Irradiation;	A 26% B n/a C 34%

sodium 2-chloro-1,1,2,2-tetrafluoroethanesulfinate (89740-32-9) + propargyl bromide (106-96-7) → 1,1,2,2-tetrafluoro-1-bromo-2-chloroethane (354-53-0) + 5-chloro-4,4,5,5-tetrafluoro-1,2-pentadiene (132673-96-2) + 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With ammonium peroxydisulfate In N,N-dimethyl-formamide at 40℃; for 4h;	A 30% B 32% C 12%

methanol (67-56-1) + chlordifluoroacetyl chloride (354-24-5) → Difluoroacetic acid (381-73-7) + difluoroacetic acid methyl ester (433-53-4) + metyhyl chlorodifluoroacetate (1514-87-0) + 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With zinc at 20℃; for 1 - 3h; Product distribution / selectivity; Heating / reflux;	A 2.6% B 16.7% C 0% D 28.6%

metyhyl chlorodifluoroacetate (1514-87-0) → Difluoroacetic acid (381-73-7) + difluoroacetic acid methyl ester (433-53-4) + 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With methanol; zinc at 50℃; for 1 - 4h; Product distribution / selectivity; Heating / reflux;	A 0.3% B 26.8% C 0%

Difluoroacetic acid (381-73-7) → 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With chlorine im direkten Sonnenlicht;

1,1,3-trichloro-1,3,3-trifluoroacetone (79-52-7) → 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With alkali hydroxide; benzene
With alkaline solution; benzene
With ammonium hydroxide

chlorodifluoroacetyl fluoride (354-27-8) → 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With water

1,1,1,3-tetrachloro-3,3-difluoro-propan-2-one (758-41-8) → 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With alkali hydroxide; benzene
With alkaline solution; benzene
With ammonium hydroxide

1,3-dichloro-1,1,3,3-tetrafluoro-propan-2-one (127-21-9) → 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With alkali hydroxide; benzene
With alkaline solution; benzene

3.3.-difluoro-1.1.2.3-tetrachloro-propene-(1) → 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With alkaline KMNO4 at 70℃;
With alkaline KMNO4 at 70℃;

difluorochloroacetyl chloride → 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With water

1,1,3-trichloro-1,3,3-trifluoroacetone (79-52-7) + benzene (71-43-2) + potassium hydroxide → Dichlorofluoromethane (75-43-4) + 2-chloro-2,2-difluoroacetic acid (76-04-0)

1,1,1,3-tetrachloro-3,3-difluoro-propan-2-one (758-41-8) + aqueous NaOH-solution → chloroform (67-66-3) + 2-chloro-2,2-difluoroacetic acid (76-04-0)

trichlorofluoromethane (75-69-4) + ethyl 2-chloro-2,2-difluoroacetate (383-62-0) → 1,1,3-trichloro-2-ethoxy-1,3,3-trifluoro-propan-2-ol + 1,3-dichloro-1,3,3-trifluoroacetone (56753-83-4) + 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
Stage #1: trichlorofluoromethane; ethyl 2-chloro-2,2-difluoroacetate With aluminium; mercury dichloride In N,N-dimethyl-formamide Stage #2: With hydrogenchloride In N,N-dimethyl-formamide Title compound not separated from byproducts;

2-chloro-2,2-difluoronitroethane → 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With sulfuric acid

chlorodifluoroacetic anhydride (ClF2CO)2O + 2-chlorodifluoroethyl-4,5-dicyanoimidazol3 + aminosulfonic acid (5329-14-6) + diaminomaleonitrile (1187-42-4) → 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With sodium carbonate In diethylene glycol dimethyl ether; water

chlorodifluoroselenoacetic acid → 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With water

chlordifluoroacetyl chloride (354-24-5) → 2-chloro-2,2-difluoroacetic acid (76-04-0)

Conditions	Yield
With water at 20 - 100℃;

p-cresol (106-44-5) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → difluoro-(4-methylphenoxy)acetic acid (207803-79-0)

Conditions	Yield
With sodium hydride In 1,4-dioxane for 3h; Heating;	100%

pent-1-yn-5-ol (5390-04-5) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → C7H7ClF2O2

Conditions	Yield
With sulfuric acid In toluene at 110℃; for 10h;	98.3%

5-Hexen-1-ol (821-41-0) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → 2-chloro-2,2-difluoroacetic acid allylhexyl ester

Conditions	Yield
With dodecatungstosilic acid In 5,5-dimethyl-1,3-cyclohexadiene at 130℃; for 5h;	98.2%

5-hexyl-1-ol (928-90-5) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → C8H9ClF2O2

Conditions	Yield
With sulfuric acid In toluene at 110℃; for 10h;	98.1%

homoalylic alcohol (627-27-0) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → 2-chloro-2,2-difluoroethylene butyl acetate (881903-10-2)

Conditions	Yield
With dodecatungstosilic acid In toluene at 110℃; for 10h;	97.8%
With toluene-4-sulfonic acid In hexane for 3h; Heating / reflux;	85%

n-Pent-4-enyl alcohol (821-09-0) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → 2-chloro-2,2-difluoroacetate allyl pentyl ester

Conditions	Yield
With phosphotungstic acid In toluene at 100℃; for 10h; Temperature; Solvent;	97.6%

propargyl alcohol (107-19-7) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → propargyl 2-chloro-2,2-difluoroacetate (118373-19-6)

Conditions	Yield
With sulfuric acid; toluene-4-sulfonic acid In cyclohexane at 60℃; for 15h;	97.6%

α-naphthol (90-15-3) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → 2,2-difluoro-2-(naphthalen-1-yloxy)acetic acid

Conditions	Yield
Stage #1: α-naphthol With sodium hydride In 1,4-dioxane Inert atmosphere; Schlenk technique; Reflux; Stage #2: 2-chloro-2,2-difluoroacetic acid at 0℃; Inert atmosphere; Schlenk technique; Reflux;	97%

(Z)-4-benzyloxy-but-2-en-1-ol (81028-03-7) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → chlorodifluoroacetic acid (Z)-5-benzyloxy-pent-2-enyl ester (807378-02-5)

Conditions	Yield
With sulfuric acid In toluene for 7h; Heating;	96%

4-methoxy-phenol (150-76-5) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → 2,2-difluoro-2-(4-methoxyphenoxy)acetic acid

Conditions	Yield
Stage #1: 4-methoxy-phenol With sodium hydride In 1,4-dioxane Inert atmosphere; Schlenk technique; Reflux; Stage #2: 2-chloro-2,2-difluoroacetic acid at 0℃; Inert atmosphere; Schlenk technique; Reflux;	96%

4-Phenylphenol (92-69-3) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → 2-([1,1'-biphenyl]-4-yloxy)-2,2-difluoroacetic acid

Conditions	Yield
Stage #1: 4-Phenylphenol With sodium hydride In 1,4-dioxane Inert atmosphere; Schlenk technique; Reflux; Stage #2: 2-chloro-2,2-difluoroacetic acid at 0℃; Inert atmosphere; Schlenk technique; Reflux;	96%

2-chloro-2,2-difluoroacetic acid (76-04-0) → trifluoroacetic acid (76-05-1)

Conditions	Yield
With potassium fluoride In water at 140℃; for 1h;	95%

(+/-)-1-trimethylsilyl-1-pentyn-3-ol (18269-90-4) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → C10H15ClF2O2Si

Conditions	Yield
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In dichloromethane at 0 - 20℃; Inert atmosphere;	95%

N-methylcarbazole (1484-12-4) + chlorodifluoroacetic anhydride (2834-23-3) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → C15H10Cl2FNO

Conditions	Yield
In 1,2-dichloro-ethane at 100℃; Friedel-Crafts Acylation; Schlenk technique;	95%

chlorodifluoroacetic anhydride (2834-23-3) + 3,6,9-trimethyl-9H-carbazole (66294-86-8) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → C17H14Cl2FNO

Conditions	Yield
In 1,2-dichloro-ethane at 100℃; Friedel-Crafts Acylation; Schlenk technique;	94%

p-Chlorothiophenol (106-54-7) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → 2-((4-chlorophenyl)thio)-2,2-difluoroacetic acid (16503-81-4)

Conditions	Yield
Stage #1: p-Chlorothiophenol With sodium hydride In 1,4-dioxane Inert atmosphere; Schlenk technique; Reflux; Stage #2: 2-chloro-2,2-difluoroacetic acid at 0℃; Inert atmosphere; Schlenk technique; Reflux;	92%

1-butyn-4-ol (927-74-2) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → C6H5ClF2O2

Conditions	Yield
With phosphoric acid; sulfuric acid In toluene at 110℃; for 10h;	90.2%

methyl magnesium iodide (917-64-6) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → 1-chloro-1,1-difluoroacetone monohydrate (88257-33-4)

Conditions	Yield
In diethyl ether at 10℃; for 0.5h;	90%
In diethyl ether

4-Fluorothiophenol (371-42-6) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → α,α-difluoro(4-fluorophenylthio)acetic acid (911360-86-6)

Conditions	Yield
Stage #1: 4-Fluorothiophenol; 2-chloro-2,2-difluoroacetic acid With sodium hydride In 1,4-dioxane at 0 - 100℃; for 3h; Stage #2: With hydrogenchloride In 1,4-dioxane; ethanol; water at 0℃;	90%

C21H24O4 + 2-chloro-2,2-difluoroacetic acid (76-04-0) → C21H21ClF2O4

Conditions	Yield
Stage #1: C21H24O4 With diisobutylaluminium hydride In dichloromethane at -78℃; Stage #2: 2-chloro-2,2-difluoroacetic acid In dichloromethane; chloroform Reflux;	90%

para-bromobenzenethiol (106-53-6) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → α,α-difluoro(4-bromophenylthio)acetic acid

Conditions	Yield
Stage #1: para-bromobenzenethiol With sodium hydride In 1,4-dioxane Inert atmosphere; Schlenk technique; Reflux; Stage #2: 2-chloro-2,2-difluoroacetic acid at 0℃; Inert atmosphere; Schlenk technique; Reflux;	90%

5-methoxy-N-methylindole (2521-13-3) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → 2-chloro-2,2-difluoro-1-(5-methoxy-1-methyl-1H-indol-3-yl)-ethan-1-one (1620097-97-3)

Conditions	Yield
In 1,2-dichloro-ethane at 100℃; Friedel-Crafts Acylation;	89%

2.6-dimethylphenol (576-26-1) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → 2-(2,6-dimethylphenoxy)-2,2-difluoroacetic acid

Conditions	Yield
Stage #1: 2.6-dimethylphenol With sodium hydride In 1,4-dioxane Inert atmosphere; Schlenk technique; Reflux; Stage #2: 2-chloro-2,2-difluoroacetic acid at 0℃; Inert atmosphere; Schlenk technique; Reflux;	89%

thiophenol (108-98-5) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → 2,2-difluoro-2-(phenylthio)acetic acid (46207-56-1)

Conditions	Yield
Stage #1: thiophenol With sodium hydride In 1,4-dioxane Inert atmosphere; Schlenk technique; Reflux; Stage #2: 2-chloro-2,2-difluoroacetic acid at 0℃; Inert atmosphere; Schlenk technique; Reflux;	88%

n-hexylmagnesium bromide (3761-92-0) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → Chlorodifluoromethyl n-hexyl ketone (86340-68-3)

Conditions	Yield
In diethyl ether at -20℃; for 12h;	87%
In diethyl ether at -78 - 0℃;

phenylmagnesium bromide (100-58-3) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → 2-chloro-2,2-difluoroacetophenone (384-67-8)

Conditions	Yield
With sodium hydroxide	87%

(S,E)-4,5-bis(benzyloxy)pent-2-en-1-ol (1001273-06-8) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → (S,E)-4,5-bis(benzyloxy)pent-2-enyl 2-chloro-2,2-difluoroacetate (1001273-08-0)

Conditions	Yield
In chloroform for 10h; Heating;	87%

1,6-dimethyl-1H-indole (5621-15-8) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → 2-chloro-1-(1,6-dimethyl-1H-indol-3-yl)-2,2-difluoroethan-1-one

Conditions	Yield
In 1,2-dichloro-ethane at 100℃; Friedel-Crafts Acylation;	87%

triethylsilane (617-86-7) + 2-chloro-2,2-difluoroacetic acid (76-04-0) → C14H31ClF2O2Si2

Conditions	Yield
With tris(pentafluorophenyl)borate In dichloromethane at 23℃; for 1h;	87%

Upstream product

• 79-52-7 1,1,3-trichloro-1,3,3-trifluoroacetone 
• 354-27-8 chlorodifluoroacetyl fluoride 
• 758-41-8 1,1,1,3-tetrachloro-3,3-difluoro-propan-2-one 
• 76-13-1 1,1,2-Trichloro-1,2,2-trifluoroethane 
• 354-24-5 chlordifluoroacetyl chloride 
• 383-62-0 ethyl 2-chloro-2,2-difluoroacetate 
• 1514-87-0 metyhyl chlorodifluoroacetate 
• 5329-14-6 aminosulfonic acid 
• 1187-42-4 diaminomaleonitrile 
• 67-56-1 methanol 
• 75-69-4 trichlorofluoromethane 
• 71-43-2 benzene 
• 89740-32-9 sodium 2-chloro-1,1,2,2-tetrafluoroethanesulfinate 
• 106-96-7 propargyl bromide 

Downstream Products

• 207803-79-0 difluoro-(4-methylphenoxy)acetic acid 
• 100836-26-8 bis(chlorodifluoroacetato)nitrosylbis(triphenylphosphine)rhodium 
• 1149363-14-3 C₂₁H₂₁ClF₂O₄ 
• 1312759-86-6 2-chloro-N-(4-(4-[2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl]piperazin-1-yl)phenyl)-2,2-difluoroacetamide 
• 1312759-99-1 2-chloro-N-(4-(4-[2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl]piperazin-1-yl)-3-fluorophenyl)-2,2-difluoroacetamide 
• 1398519-64-6 (3-bromophenyl)(4-difluoromethoxyphenyl)methanone 
• 64-17-5 ethanol 
• 885132-72-9 1-(4-difluoromethoxy-3-hydroxy-phenyl)-ethanone 
• 885132-71-8 3,4-bis(difluoromethoxy)acetophenone 
• 1191047-19-4 C₂₅H₂₁F₅O₅ 
• 1040723-84-9 C₉H₇ClF₂O₃ 
• 1062614-42-9 4-bromo-2-chloro-1-(difluoromethoxy)benzene 
• 1062613-63-1 1-(difluoromethoxy)-4-iodo-2-methylbenzene 
• 100514-80-5 RuH(OCOCF₂Cl)(CO)(P(C₆H₅)3)2 

Relevant articles and documents

Synthesis production process of difluorochloroacetic acid

The invention discloses a synthesis production process of difluorochloroacetic acid, comprising the following steps: charging sulfur trioxide with nitrogen gas into an oxidation reaction kettle by an intermittent process, starting stirring; after reaching a certain temperature, adding difluorotetrachloroethane and catalyst according to a predetermined ratio into the oxidation reaction kettle; heating for reaction, observing the backflow condition, starting steaming the byproduct sulfuric chloride when the kettle temperature rises to a certain temperature while the backflow is small; after steaming the byproduct sulfuric chloride, carrying out charging for the second time; carrying out three-stage spray hydrolysis and absorption on the product difluorochloracetyl chloride to generate crude product difluorochloroacetic acid, and carrying out defluorination and rectification on the crude product to obtain finished product difluorochloroacetic acid. The synthesis production process of difluorochloroacetic acid disclosed by the invention adopts the difluorotetrachloroethane as a raw material, the finished product difluorochloroacetic acid is prepared by oxidation reaction, the preparation process has reasonable design, high absorption rate, high overall yield and low energy consumption; and the byproduct can be hydrolyzed and reused, so that the production process is clean, environment-friendly, safe and reliable.

Preparation and properties of two novel selenoacetic acids: HCF 2C(O)SeH and ClCF2C(O)SeH

The novel selenocarboxylic Se-acids, HCF2C(O)SeH and ClCF 2C(O)SeH, were prepared by treating the corresponding carboxylic acids with Woollins' reagent. The boiling points were extrapolated from the vapor pressure curves to be 364 and 359 K for HCF2C(O)SeH and ClCF2C(O)SeH, respectively. Both compounds are unstable at ambient temperatures and decompose to the corresponding seleno anhydrides and release of H2Se. Hydrolysis results in formation of the carboxylic acids and hydrogen selenide, while diselenides presumably are obtained by oxidation. The conformational properties of these acids were studied by vibrational spectroscopy in combination with ab initio and DFT methods. IR vapor-phase spectra, Raman spectra of the neat liquids, and IR spectra of the Ar-matrix-isolated compounds deposited at two different nozzle temperatures were interpreted in terms of quenching conformational equilibria. The most stable structure of both acids was found to be syn-gauche in equilibrium with a second anti-syn form in HCF2C(O)SeH and with another two conformers, anti-gauche and anti-syn, in ClCF2C(O)SeH.

Preparation of compounds comprising a CHF2 or CHF group

Producing compounds (I) with a mono- or difluoromethyl group from compounds (II) with a mono- or difluorohalomethyl group, where halo is bromo, iodo or preferably chloro, comprises reacting (II) with zinc in the presence of an alcohol. An independent claim is also included for an azeotropic mixture of methyl difluoroacetate and methanol.