171887-03-9

Basic information

• Product Name: N-(2-Amino-4,6-dichloro-5-pyrimidinyl)formamide
• Synonyms: N-(2-Amino-4.6-dichloro-5-pyrimdinyl) formamide;2-Amino-4,6-dichloro-5-pyrimidinyl formamide;2,5-Diamino-4,6-DichloroformamidoHcl;N-(2-Amino-4,6-Dichloro-5-Pyri;N-(2-AMINO-4,6-DICHLOROPYRIMIDIN-5-YL) FORMAMIDE[FOR ABACAVIR];2-Amino-4,6-dichloro-5-formamidopyrimidine;N-(2-Amino-4,6-dichloro-5-pyrimidinyl)formamide;N-(2-Amino-4,6-dichloropyrimidin-5-yl)formamide
• CAS NO: 171887-03-9
• Molecular Formula: C₅H₄Cl₂N₄O
• Molecular Weight: 207.01746
• EINECS: 425-650-6
• Product Categories: Heterocycle;Heterocyclic Compounds;Bases & Related Reagents;Heterocycles;Nucleotides;Heterocycle-Pyrimidine series
• Mol File: 171887-03-9.mol
• Article Data: 9

Chemical Properties

• Boiling Point: 554.77 °C at 760 mmHg
• Flash Point: 289.315 °C
• Appearance: /
• Density: 1.742 g/cm³
• Vapor Pressure: 0mmHg at 25°C
• Refractive Index: 1.706
• Storage Temp.: under inert gas (nitrogen or Argon) at 2–8 °C
• Solubility: DMSO, Methanol
• PKA: 10.90±0.70(Predicted)
• CAS DataBase Reference: N-(2-Amino-4,6-dichloro-5-pyrimidinyl)formamide(CAS DataBase Reference)
• NIST Chemistry Reference: N-(2-Amino-4,6-dichloro-5-pyrimidinyl)formamide(171887-03-9)
• EPA Substance Registry System: N-(2-Amino-4,6-dichloro-5-pyrimidinyl)formamide(171887-03-9)

Safety Data

• Hazardous Substances Data: 171887-03-9(Hazardous Substances Data)

Usage

Chemical Properties

White crystalline powder

Uses

Different sources of media describe the Uses of 171887-03-9 differently. You can refer to the following data:
1. N-(2-Amino-4,6-dichloro-5-pyrimidinyl)formamide (Abacavir - In House Impurity) is an intermediate of Abacavir (A105000). Abacavir is a carbocyclic 2''-deoxyguanosine nucleoside reverse transcriptase inhibitor and an anti-HIV drug used to treat HIV infection (1). Intracellular enzymes convert Abacavir to its active form, carbovir-triphosphate (CBV-TP), which then selectively inhibits HIV reverse transcriptase by incorporating into viral DNA (2). Abacavir is metabolized in the liver by uridine diphosphate glucuronyltransferase and alcohol dehydrogenase resulting in inactive glucuronide and carboxylate metabolites, respectively.
2. Abacavir intermediate. A purine derivative

InChI:InChI=1/C5H4Cl2N4O/c6-3-2(9-1-12)4(7)11-5(8)10-3/h1H,(H,9,12)(H2,8,10,11)

Synthetic route

2-nitroso-4,6-dichloro-5-formamidopyrimidine → N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9)

Conditions	Yield
With 5%-palladium/activated carbon; hydrogen In methanol at 40℃; under 7500.75 - 11251.1 Torr; for 4h; Temperature; Autoclave;	98%

formic acid (64-18-6) + 2,5-diamino-4,6-dichloropyrimidine (55583-59-0) → N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9)

Conditions	Yield
Stage #1: formic acid; 2,5-diamino-4,6-dichloropyrimidine at 50 - 55℃; for 3h; Stage #2: In toluene at 50℃; under reduced pressure;	90%

2,5-diamino-4,6-dihydroxypyrimidine hydrochloride + N,N-dimethyl-formamide (68-12-2, 33513-42-7) → N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9)

Conditions	Yield
With thionyl chloride; trichlorophosphate at 80℃; for 2.5h; Temperature;	82.6%

2-amino-5-{[(dimethylamino)methylene]amino}-4,6-dichloropyrimidine (171887-02-8) → N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9)

Conditions	Yield
In phosphate buffer for 4h; pH=3.2; Hydrolysis; Heating;	72%

2-Amino-4,6-dichloro-5-[(dimethylamino)methyleneamino]pyrimidine → N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9)

Conditions	Yield
With potassium dihydrogenphosphate; phosphoric acid In chloroform methanol	68%

2,5-Diamino-4,6-dihydroxypyrimidine hydrochloride (56830-58-1) + N,N-dimethyl-formamide (68-12-2, 33513-42-7) → N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9)

Conditions	Yield
Stage #1: N,N-dimethyl-formamide With trichlorophosphate at 50℃; for 0.75h; Stage #2: 2,5-Diamino-4,6-dihydroxypyrimidine hydrochloride at 70 - 90℃; for 17.45 - 20.45h; Stage #3: With sodium hydroxide; water at 20 - 97℃; for 4 - 8h; pH=0.5 - 4.0; Product distribution / selectivity;	37.4%

4,6-Dichloro-2,5-bis-[(dimethylamino)methyleneamino]pyrimidine + 2,5-Diamino-4,6-dihydroxypyrimidine hydrochloride (56830-58-1) → N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9)

Conditions	Yield
With sodium hydroxide; phosphoric acid; trichlorophosphate In N-methyl-acetamide; water; toluene

2,5-Diamino-4,6-dihydroxypyrimidine hydrochloride (56830-58-1) → N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9)

Conditions	Yield
With sodium hydroxide; trichlorophosphate In N-methyl-acetamide; water
With sodium hydroxide; trichlorophosphate In N-methyl-acetamide; water

2,5-bis{[(dimethylamino)methylene]amino}-4,6-dichloropyrimidine (171887-01-7) → N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9)

Conditions	Yield
With sodium hydroxide; phosphoric acid; water at 100℃; for 4h; pH=4; Product distribution / selectivity;

2,5-diamino-4,6-dichloropyrimidine (55583-59-0) → N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9)

Conditions	Yield
With formic acid In water; toluene

N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) + 1-t-Butoxycarbonylpiperazine (57260-71-6) → 4-[2-amino-6-chloro-5-(formylamino)pyrimidin-4-yl]piperazine-1-carboxylic acid tert-butyl ester (1435953-79-9)

Conditions	Yield
With N-ethyl-N,N-diisopropylamine In 1,4-dioxane at 55℃; for 1h;	100%
With N-ethyl-N,N-diisopropylamine In 1,4-dioxane at 55℃; for 1h;	100%
With N-ethyl-N,N-diisopropylamine In 1,4-dioxane at 55℃; for 1h;	100%

N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → 7-chlorothiazolo[5,4-d]pyrimidin-5-amine (1211527-74-0)

Conditions	Yield
With Lawessons reagent In tetrahydrofuran at 65℃; for 0.5h;	93.4%
With Lawessons reagent In tetrahydrofuran at 65℃; for 0.5h;	93.4%
With Lawessons reagent In tetrahydrofuran at 65℃; for 0.5h;	93.4%

(3-methyl-4-nitrophenyl)methanamine hydrochloride (1037397-91-3) + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → N-[2-amino-4-chloro-6-(3-methyl-4-nitro-benzylamino)-pyrimidin-5-yl]-formamide (1040353-71-6)

Conditions	Yield
With triethylamine In isopropyl alcohol at 58 - 65℃; for 3.5 - 4.66667h; Heating / reflux;	92%

((1S,4R)-4-aminocyclopent-2-enyl)methanol D-hydrogen tartrate + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → (1R,4S)-1-[(2-amino-6-chloro-5-formamido-4-pyrimidinyl)amino]-4-(hydroxymethyl)-2-cyclopentene (171887-04-0)

Conditions	Yield
Stage #1: ((1S,4R)-4-aminocyclopent-2-enyl)methanol D-hydrogen tartrate With sodium carbonate In isopropyl alcohol at 20℃; for 1h; Stage #2: N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide In isopropyl alcohol Concentration; Solvent; Reflux;	88.2%

(1S,2R,3S,4R,5R)-4-[((1,1-dimethylethyl)dimethylsilyloxy)]-5-[((1,1-dimethylethyl)dimethyl-silyloxy)methyl]-3-fluorobicyclo[3.1.0]hexan-2-amine + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → C24H43ClFN5O3Si2

Conditions	Yield
With N-ethyl-N,N-diisopropylamine In 1,4-dioxane at 100℃; for 12h; Microwave irradiation;	88%
With N-ethyl-N,N-diisopropylamine In 1,4-dioxane at 100℃; for 12h; Microwave irradiation;	88%

(1R,4S)-1-amino-4-hydroxymethyl-2-cyclopentene (136522-35-5) + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → (1R,4S)-1-[(2-amino-6-chloro-5-formamido-4-pyrimidinyl)amino]-4-(hydroxymethyl)-2-cyclopentene (171887-04-0)

Conditions	Yield
With triethylamine In ethanol; water	85%
With triethylamine In ethanol for 7h; Substitution; Heating;	83%
With sodium hydroxide; triethylamine In acetic acid 1-hydroxy-propyl ester; ethanol
Stage #1: (1R,4S)-1-amino-4-hydroxymethyl-2-cyclopentene; N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide With triethylamine In industrial methylated spirit; water for 17h; Heating / reflux; Stage #2: With potassium carbonate In industrial methylated spirit at 25 - 30℃; for 0.5h; Stage #3: In industrial methylated spirit at 0 - 5℃; Product distribution / selectivity;
Stage #1: (1R,4S)-1-amino-4-hydroxymethyl-2-cyclopentene; N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide With sodium hydrogencarbonate In idustrial methylated spirit; water for 4h; Heating / reflux; Stage #2: In industrial methylated spirit at -5℃; for 1h; Product distribution / selectivity;

((1R*,3R*,4R*)-3-aminobicyclo[2.2.1]heptan-1-yl)methanol + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → [(1R*,3R*,4R*)-3-(2-amino-6-chloro-9H-purin-9-yl)bicyclo[2.2.1]hept-1-yl]methanol

Conditions	Yield
With N-ethyl-N,N-diisopropylamine In ethanol; water at 140℃; for 1h; Microwave irradiation; Sealed tube;	83%

(4-aminobicyclo[2.2.1]hept-1-yl)methanol + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → [4-(2-amino-6-chloro-9H-purin-9-yl)bicyclo[2.2.1]hept-1-yl]methanol

Conditions	Yield
With N-ethyl-N,N-diisopropylamine In butan-1-ol at 160℃; for 2h; Sealed tube; Microwave irradiation;	81%

4-aminobenzamide (2835-68-9) + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → 4-(2-amino-6-((4-carbamoylphenyl)amino)9H-purin-9-yl)benzamide

Conditions	Yield
In 1,4-dioxane; water Reflux;	79%

N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → 2,5-diamino-4,6-dichloropyrimidine (55583-59-0)

Conditions	Yield
With hydrogenchloride In ethanol; water for 6h; Hydrolysis; Heating;	77%
In hydrogenchloride; ethanol	65%

((1R,2R,3S,4R)-4-amino-2,3-bis((tert-butyldimethylsilyl)oxy)cyclopentyl)methanol + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → ((1R,2R,3S,4R)-4-(2-amino-6-chloro-9H-purin-9-yl)-2,3-bis((tert-butyldimethylsilyl)oxy)cyclopentyl)methanol

Conditions	Yield
With N-ethyl-N,N-diisopropylamine In butan-1-ol at 160℃; for 24h; Sealed tube;	75%
With N-ethyl-N,N-diisopropylamine; butan-1-ol at 160℃; for 24h; Sealed tube;	75%
With N-ethyl-N,N-diisopropylamine In butan-1-ol at 160℃; for 24h; Sealed tube;

(1R,4S)-1-amino-4-(hydroxymethyl)-2-cyclopentene hydrochloride + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → (1R,4S)-1-[(2-amino-6-chloro-5-formamido-4-pyrimidinyl)amino]-4-(hydroxymethyl)-2-cyclopentene (171887-04-0)

Conditions	Yield
With sodium hydroxide; triethylamine In 2-methyl-propan-1-ol	74%
Stage #1: (1R,4S)-1-amino-4-(hydroxymethyl)-2-cyclopentene hydrochloride With sodium hydrogencarbonate In isopropyl alcohol at 20℃; for 1h; Stage #2: N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide In isopropyl alcohol Concentration; Reagent/catalyst; Reflux;	51.4%
Stage #1: (1R,4S)-1-amino-4-(hydroxymethyl)-2-cyclopentene hydrochloride With sodium hydrogencarbonate In ethanol at 20℃; for 0.5h; Inert atmosphere; Stage #2: N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide In ethanol at 75 - 80℃; for 3h; Inert atmosphere;

(S)-(6-(((tetrahyd rofuran-3-yl)oxy)methyl)pyridin-2-yl)methanamine (1202402-79-6) + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → N-[2-amino-4-chloro-6-((6-[(S)-(tetrahydro-furan-3-yl)oxymethyl]pyridin-2-ylmethyl)amino)pyrimidin-5-yl]formamide (1202402-77-4)

Conditions	Yield
With triethylamine In isopropyl alcohol for 2h; Reflux;	73%

(±)-cis-3-aminocyclopentanol + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → 2-amino-6-chloro-9-(cis-3′-hydroxycyclopentyl)purine

Conditions	Yield
With N-ethyl-N,N-diisopropylamine In ethanol; water at 140℃; for 1.5h; Microwave irradiation; Sealed tube;	72%

(1S,2R,3S,4R,5R)-4-[((1,1-dimethylethyl)dimethylsilyloxy)]-5-[((1,1-dimethylethyl)dimethyl-silyloxy)methyl]-3-fluorobicyclo[3.1.0]hexan-2-amine + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → C24H43ClFN5O3Si2 + C24H41ClFN5O2Si2

Conditions	Yield
With N-ethyl-N,N-diisopropylamine In toluene at 160℃; for 2h; Microwave irradiation;	A 70% B 24%
With N-ethyl-N,N-diisopropylamine In butan-1-ol at 160℃; for 2h; Solvent; Microwave irradiation;	A 59% B 40%

(3aR,4S,6R,6aS)-6-amino-2,2-dimethyltetrahydro-3aH-cyclopenta[d][1,3]dioxol-4-ol (155899-66-4) + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → 9-[(1′R,2′S,3′R,4′S)-4′-hydroxy-2′,3′-O-isopropylidene-cyclopentan-1′-yl]-2-amino-6-chloro-9H-purine

Conditions	Yield
With N-ethyl-N,N-diisopropylamine In butan-1-ol at 120℃;	66%

(1SR,2SR,4SR)-4-aminobicyclo[2.2.1]heptan-2-ol hydrochloride + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → 4-(2-amino-6-chloro-9H-purin-9-yl)bicyclo[2.2.1]heptan-2-ol

Conditions	Yield
With N-ethyl-N,N-diisopropylamine In butan-1-ol at 160℃; for 2h; Microwave irradiation;	63%

C7H11N + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → C12H12ClN5 (1621165-38-5)

Conditions	Yield
With N-ethyl-N,N-diisopropylamine In butan-1-ol at 160℃; for 2h; Sealed tube; Microwave irradiation;	57%

4-pentylbicyclo[2.2.2]oct-1-ylamine + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → C18H26ClN5 (1621165-41-0)

Conditions	Yield
With N-ethyl-N,N-diisopropylamine In butan-1-ol at 160℃; for 2h; Sealed tube; Microwave irradiation;	57%

N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) + (3aS,4R,6R,6aR)-6-((methoxymethoxy)methyl)-2,2-dimethyltetrahydro-3aH-cyclopenta[d][1,3]dioxol-4-amine (90597-13-0) → (1R,2S,3R,4R)-1-[(2-amino-6-chloro-5-formamido-4-pyrimidinyl)amino]-2,3-isopropylidenedioxy-4-(methoxymethoxymethyl)cyclopentane (1203452-14-5)

Conditions	Yield
With triethylamine In ethanol for 7h; Reflux;	51.5%

(4R,3R,1R)-4-amino-3-hydroxy-1-trityloxymethylphospholane 1-oxide + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → (4R,3R,1R)-4-(guanin-9-yl)-3-hydroxy-1-hydroxymethylphospholane 1-oxide

Conditions	Yield
Stage #1: (4R,3R,1R)-4-amino-3-hydroxy-1-trityloxymethylphospholane 1-oxide; N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide With N-ethyl-N,N-diisopropylamine In butan-1-ol at 130℃; for 16h; Stage #2: With hydrogenchloride In methanol at 60℃; for 16h;	48%

2-(6-(aminomethyl)pyridin-2-yl)propan-2-ol (1202403-02-8) + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → 7-chloro-3-(6-[1-hydroxy-1-methylethyl]pyridine-2-ylmethyl)-3H-[1,2,3]triazolo[4,5-d]pyrimidin-5-amine (1202402-84-3)

Conditions	Yield
Stage #1: 2-(6-(aminomethyl)pyridin-2-yl)propan-2-ol; N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide With triethylamine In isopropyl alcohol at 90℃; for 4h; Stage #2: With hydrogenchloride In ethanol; water at 90℃; for 2h; Stage #3: With sodium nitrite In ethanol; water at 0℃;	47%

(4S,3S,1R)-4-amino-3-hydroxy-1-trityloxymethylphospholane 1-oxide + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → (4S,3S,1R)-4-(guanin-9-yl)-3-hydroxy-1-hydroxymethylphospholane 1-oxide

Conditions	Yield
Stage #1: (4S,3S,1R)-4-amino-3-hydroxy-1-trityloxymethylphospholane 1-oxide; N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide With N-ethyl-N,N-diisopropylamine In butan-1-ol at 130℃; for 16h; Stage #2: With hydrogenchloride In methanol at 60℃; for 16h;	45%

tert-butyl 5,8-diazaspiro[3.5]nonane-8-carboxylate (886766-31-0) + N-(2-amino-4,6-dichloropyrimidin-5-yl)formamide (171887-03-9) → tert-butyl 9-(2-amino-6-chloro-5-formamidopyrimidin-4-yl)-6,9-diazaspiro[3.5]-nonane-6-carboxylate (1435953-91-5)

Conditions	Yield
With N-ethyl-N,N-diisopropylamine In dichloromethane for 20h;	22%
With N-ethyl-N,N-diisopropylamine In 1,4-dioxane at 100℃; for 168h;	0.44 g

Upstream product

• 56830-58-1 2,5-Diamino-4,6-dihydroxypyrimidine hydrochloride 
• 68-12-2 N,N-dimethyl-formamide 
• 55583-59-0 2,5-diamino-4,6-dichloropyrimidine 
• 171887-01-7 2,5-bis{[(dimethylamino)methylene]amino}-4,6-dichloropyrimidine 
• 64-18-6 formic acid 
• 171887-02-8 2-amino-5-{[(dimethylamino)methylene]amino}-4,6-dichloropyrimidine 

Downstream Products

• 171887-04-0 (1R,4S)-1-[(2-amino-6-chloro-5-formamido-4-pyrimidinyl)amino]-4-(hydroxymethyl)-2-cyclopentene 
• 55583-59-0 2,5-diamino-4,6-dichloropyrimidine 
• 75797-17-0 C₁₁H₁₄ClN₅O₃ 
• 1447817-19-7 8-(5-aminothiazolo[5,4-d]pyrimidin-7-yl)-N-(4-methoxyphenyl)-3,8-diazabicyclo[3.2.1]-octane-3-carboxamide 
• 1435953-71-1 methyl 2-{1-(5-aminothiazolo[5,4-d]pyrimidin-7-yl)-4-[(4-methoxyphenyl)carbamoyl]-piperazin-2-yl}acetate 
• 1435953-63-1 (3S)-4-(5-aminothiazolo[5,4-d]pyrimidin-7-yl)-3-isobutyl-N-(4-methoxyphenyl)-piperazine-1-carboxamide 
• 1435953-62-0 (3S)-4-(5-aminothiazolo[5,4-d]pyrimidin-7-yl)-3-cyclopropyl-N-(4-methoxyphenyl)-piperazine-1-carboxamide 
• 1435953-60-8 (3S)-4-(5-aminothiazolo[5,4-d]pyrimidin-7-yl)-3-ethyl-N-(4-methoxyphenyl)piperazine-1-carboxamide 
• 1435953-16-4 (3S)-4-(5-aminothiazolo[5,4-d]pyrimidin-7-yl)-N-(4-methoxy-2-methyl-phenyl)-3-methyl-piperazine-1-carboxamide 
• 1435952-54-7 (S)-3-[4-(5-aminothiazolo[5,4-d]pyrimidin-7-yl)-3-methylpiperazin-1-yl]-4-(phenyl-amino)cyclobut-3-ene-1,2-dione 

Relevant articles and documents

Preparation method of 2-amino-4, 6-dichloro-5-formamidopyrimidine

The invention provides a preparation method of 2-amino-4, 6-dichloro5formyl pyrimidine. The preparation method comprises the following steps: by taking malononitrile, formamidine or hydrochloride thereof as initial raw materials, carrying out nitrosation, formylation, cyclization, diazotization, Sandmeyer and reduction reaction to prepare the 2-amino-4, 6-dichloro-5-formamidopyrimidine. The preparation method disclosed by the invention is high in yield and high in product purity.

Method for Producing 2-Amino-4,6-Dichloro-5-Formamidopyrimidine

The invention relates to a method for producing 2-amino-4,6-dichloro-5-formamidopyrimidine from 2,5-diamino-4,6-dihydroxypyrimidine or a salt thereof. According to said method, a) 2,5-diamino-4,6-dihydroxypyrimidine or the salt or tautomer forms thereof are reacted with a chlorination agent and a formamide of formula (I) wherein R1 and R2 independently represent a C1-C4 alkyl radical or —R1-R2— represents —(CH2)n— where n=4-6, or —(CH2)2-0-(CH2)2—, without adding a solvent, at a temperature of between 50 and 130° C., b) the reaction product obtained in step a) is reacted with water at a temperature of between 0 and 100° C., and regulated to a pH value of between 1 and 6 with an inorganic base, and c) the aqueous reaction mixture obtained in step b) is left to react at a temperature of between 70 and 120° C. under hydrolysis to form 2-amino-4,6-dichloor-5-formamidopyrimidine. The inventive method enables satisfactory yields and high levels of purity of the end product to be obtained. As a result of the significantly reduced reaction volumes due to the solvent, auxiliary substances and residual substances saved, and the significantly simplified method, the costs incurred in the production of 2-amino-4,6-dichloro-5-formylaminopyrimidine are significantly reduced.

Process for the preparation of 2,5-diamino-4,6-dihalogenopyrimidinen

A halogenated hydrocarbon solvent is used in the production of 2,5-diamino-4,6-dihalo-pyrimidines (I) by reaction of 2,5-diamino-4,6-dihydroxy-pyrimidine (II) or its salts with a phosphorus oxyhalide and a quaternary ammonium halide. A halogenated hydrocarbon solvent is used in the production of 2,5-diamino-4,6-dihalo-pyrimidines of formula (I) by reaction of 2,5-diamino-4,6-dihydroxy-pyrimidine of formula (II) or its salts with a phosphorus oxyhalide and a quaternary ammonium halide. X = halo.