24448-94-0

Basic information

• Product Name: 5,5-DIMETHYLBARBITURIC ACID
• Synonyms: 5,5-DIMETHYLBARBITURIC ACID;5,5-DIMETHYL-2,4,6(1H,3H,5H)-PYRIMIDINETRIONE;LABOTEST-BB LT00847284;2,4,6(1H,3H,5H)-Pyrimidinetrione, 5,5-dimethyl-;5,5-dimethyl-1,3-diazinane-2,4,6-trione
• CAS NO: 24448-94-0
• Molecular Formula: C₆H₈N₂O₃
• Molecular Weight: 156.14
• EINECS: 246-265-8
• Product Categories: Heterocyclic Compounds;Building Blocks;C6 to C8;Chemical Synthesis;Heterocyclic Building Blocks;Pyrimidines
• Mol File: 24448-94-0.mol
• Article Data: 4

Chemical Properties

• Melting Point: 278-279 °C
• Boiling Point: 280.35°C (rough estimate)
• Flash Point: °C
• Appearance: /
• Density: 1.3889 (rough estimate)
• Refractive Index: 1.5010 (estimate)
• Water Solubility: 2.829g/L(25 oC)
• CAS DataBase Reference: 5,5-DIMETHYLBARBITURIC ACID(CAS DataBase Reference)
• NIST Chemistry Reference: 5,5-DIMETHYLBARBITURIC ACID(24448-94-0)
• EPA Substance Registry System: 5,5-DIMETHYLBARBITURIC ACID(24448-94-0)

Safety Data

• WGK Germany: 3
• Hazardous Substances Data: 24448-94-0(Hazardous Substances Data)

Usage

General Description

5,5-Dimethylbarbituric acid is a chemical compound with the molecular formula C7H10N2O3. It is a derivative of barbituric acid and is commonly used in the synthesis of pharmaceuticals and organic compounds. 5,5-DIMETHYLBARBITURIC ACID is a white crystalline solid at room temperature and is sparingly soluble in water. It is known for its sedative and hypnotic properties, and has been used in the development of sedative drugs. Additionally, 5,5-dimethylbarbituric acid has been studied for its potential use in the treatment of neurodegenerative diseases and epilepsy. Its chemical structure makes it a valuable intermediate in the production of various drugs and compounds.

InChI:InChI=1/C6H8N2O3/c1-6(2)3(9)7-5(11)8-4(6)10/h1-2H3,(H2,7,8,9,10,11)

Synthetic route

2,2-dimethylmalonic acid diethyl ester (1619-62-1) + urea (57-13-6) → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
Stage #1: 2,2-dimethylmalonic acid diethyl ester With sodium ethanolate In ethanol at 20℃; for 1h; Stage #2: urea In ethanol for 15h; Time; Reflux;	81.48%
With sodium ethanolate In ethanol at 80℃; for 16h; Inert atmosphere;	36.5 g

dimethyl sulfate (77-78-1) + sodium 5-methylbarbiturate → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
With acetic acid In water at 20℃; for 24h;	13%

sodium barbiturate + dimethyl sulfate (77-78-1) → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
With acetic acid In water at 20℃; for 24h;	3%

bis(phenyl) carbonate (102-09-0) + 2,2-dimethylmalonamide (41882-44-4) → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
at 220 - 245℃;

6-amino-5,5-dimethyl-2-thioxo-2,5-dihydro-3H-pyrimidin-4-one + acetic acid (64-19-7) → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
at 150℃; im Rohr;

urea (57-13-6) + 2,2-Dimethylmalonyl chloride (5659-93-8) → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
at 130℃;

urea (57-13-6) + 2,2-dimethylmalonic acid (595-46-0) → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
With trichlorophosphate
With sulfuric acid

2,2-dimethylmalonamide (41882-44-4) + Diethyl carbonate (105-58-8) → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
With ethanol; sodium ethanolate at 120℃;

methanol (67-56-1) + barbituric acid ; silver-salt + methyl iodide (74-88-4) → 5,5-dimethylbarbituric acid (24448-94-0)

hydrogenchloride (7647-01-0) + 2,6-diamino-5,5-dimethyl-5H-pyrimidin-4-one → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
at 130℃; im Rohr;

2,6-diamino-5,5-dimethyl-5H-pyrimidin-4-one + sulfuric acid (7664-93-9) → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
at 130℃; im Rohr;

sulfuric acid (7664-93-9) + 2-anilino-5,5-dimethyl-1H-pyrimidine-4,6-dione → 5,5-dimethylbarbituric acid (24448-94-0)

4.6-dioxo-2-thione-5.5-dimethyl-hexahydropyrimidine → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
With hydrogenchloride; dihydrogen peroxide at 50 - 60℃;

6-oxo-2.4-diimino-5.5-dimethyl-hexahydropyrimidine → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
With hydrogenchloride at 130℃; im Rohr;
With sulfuric acid

6-oxo-4-imino-2-thione-5.5-dimethyl-hexahydropyrimidine → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
With acetic acid at 150℃;

bis(phenyl) carbonate (102-09-0) + -diurethane → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
at 200 - 210℃;

urea (57-13-6) + dimethylmalonic acid ester → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
With sodium ethanolate at 100℃;
With sodium ethanolate at 100℃;

N.N'-dimethylmalonyl-guanidine → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
With hydrogenchloride at 120℃;

N-phenyl-N'.N''-dimethylmalonyl-guanidine → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
With sulfuric acid

methyl iodide (74-88-4) + silver salt of/the/ barbituric acid → 5,5-dimethylbarbituric acid (24448-94-0)

dimethyl malonamic acid (116070-49-6) → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
Multi-step reaction with 2 steps 1: KOH-solution 2: phosphorus oxychloride View Scheme

2,2-dimethylmalonic acid diethyl ester (1619-62-1) → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
Multi-step reaction with 2 steps 1: alkali / durch Verseifung 2: phosphorus oxychloride View Scheme

dimethyl dimethylmalonate (6065-54-9) → 5,5-dimethylbarbituric acid (24448-94-0)

Conditions	Yield
Multi-step reaction with 2 steps 1: methanol; sodium methylate View Scheme

chloro-trimethyl-silane (75-77-4) + 5,5-dimethylbarbituric acid (24448-94-0) + Chloro(chloromethyl)dimethylsilane (1719-57-9) → 1,3-bis[(chlorodimethylsilyl)methyl]-5,5-dimethylpyrimidine-2,4,6-trione (1240207-38-8)

Conditions	Yield
Stage #1: chloro-trimethyl-silane; 5,5-dimethylbarbituric acid With triethylamine In diethyl ether Inert atmosphere; Reflux; Stage #2: Chloro(chloromethyl)dimethylsilane In chloroform for 7h; Inert atmosphere; Heating;	98%

5,5-dimethylbarbituric acid (24448-94-0) + 4-(m-tolyl)but-3-yn-1-ol → 5,5-dimethyl-1,3-bis(4-m-tolylbut-3-ynyl)pyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In dichloromethane at 0 - 20℃; for 24h; Mitsunobu Displacement; Inert atmosphere;	98%

5,5-dimethylbarbituric acid (24448-94-0) + 4-p-tolylbut-3-yn-1-ol (31208-53-4) → 5,5-dimethyl-1,3-bis(4-p-tolylbut-3-ynyl)pyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In dichloromethane at 0 - 20℃; for 24h; Mitsunobu Displacement; Inert atmosphere;	95%

5,5-dimethylbarbituric acid (24448-94-0) + (E)-4-(3-methoxyphenyl)but-3-en-1-ol → 1,3-bis((E)-4-(3-methoxyphenyl)but-3-enyl)-5,5-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In dichloromethane at 0 - 20℃; for 24h; Mitsunobu Displacement; Inert atmosphere;	95%

(E)-4-(2-methylphenyl)-3-buten-1-ol (912456-98-5) + 5,5-dimethylbarbituric acid (24448-94-0) → 5,5-dimethyl-1,3-bis((E)-4-o-tolylbut-3-enyl)pyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In dichloromethane at 0 - 20℃; for 24h; Mitsunobu Displacement; Inert atmosphere;	93%

chloro-trimethyl-silane (75-77-4) + 5,5-dimethylbarbituric acid (24448-94-0) + chloromethylmethyldichlorosilane (1558-33-4) → 1,3-bis[(dichloro(methyl)silyl)methyl]-5,5-dimethylpyrimidine-2,4,6-trione (1240207-51-5)

Conditions	Yield
Stage #1: chloro-trimethyl-silane; 5,5-dimethylbarbituric acid With triethylamine In diethyl ether Inert atmosphere; Reflux; Stage #2: chloromethylmethyldichlorosilane In chloroform for 16h; Inert atmosphere; Reflux;	90%

5,5-dimethylbarbituric acid (24448-94-0) + 4-(trimethylsilyl)but-3-yn-1-ol (2117-12-6) → 5,5-dimethyl-1,3-bis(4-(trimethylsilyl)but-3-ynyl)pyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In dichloromethane at 0 - 20℃; for 24h; Mitsunobu Displacement; Inert atmosphere;	90%

5,5-dimethylbarbituric acid (24448-94-0) + 5-phenylpent-4-yn-1-ol (24595-58-2) → 5,5-dimethyl-1,3-bis(5-phenylpent-4-ynyl)pyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In dichloromethane at 0 - 20℃; for 24h; Mitsunobu Displacement; Inert atmosphere;	86%

5,5-dimethylbarbituric acid (24448-94-0) + (E)-4-(2,4-dichlorophenyl)but-3-en-1-ol (1426692-69-4) → 1,3-bis((E)-4-(2,4-dichlorophenyl)but-3-enyl)-5,5-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In dichloromethane at 0 - 20℃; for 24h; Mitsunobu Displacement; Inert atmosphere;	77%

5,5-dimethylbarbituric acid (24448-94-0) + (E)-4-(thiophen-3-yl)but-3-en-1-ol → 5,5-dimethyl-1,3-bis((E)-4-(thiophen-3-yl)but-3-enyl)pyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In dichloromethane at 0 - 20℃; for 24h; Mitsunobu Displacement; Inert atmosphere;	75%

5,5-dimethylbarbituric acid (24448-94-0) + (3E)-4-phenyl-3-buten-1-ol (937-58-6, 20047-19-2, 770-36-5) → 5,5-dimethyl-1,3-bis((E)-4-phenylbut-3-enyl)pyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In dichloromethane at 0 - 20℃; for 24h; Mitsunobu Displacement; Inert atmosphere;	72%

5,5-dimethylbarbituric acid (24448-94-0) + 4-phenyl-but-3-yn-1-ol (10229-11-5) → 5,5-dimethyl-1,3-bis(4-phenylbut-3-ynyl)pyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In dichloromethane at 0 - 20℃; for 24h; Mitsunobu Displacement; Inert atmosphere;	70%

5,5-dimethylbarbituric acid (24448-94-0) + (E)-4-(2-fluorophenyl)but-3-en-1-ol (113388-03-7) → 1,3-bis((E)-4-(2-fluorophenyl)but-3-enyl)-5,5-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In dichloromethane at 0 - 20℃; for 24h; Mitsunobu Displacement; Inert atmosphere;	70%

5,5-dimethylbarbituric acid (24448-94-0) + (E)-4-(3-fluorophenyl)but-3-en-1-ol → 1,3-bis((E)-4-(3-fluorophenyl)but-3-enyl)-5,5-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In dichloromethane at 0 - 20℃; for 24h; Mitsunobu Displacement; Inert atmosphere;	69%

5,5-dimethylbarbituric acid (24448-94-0) + (E)-4-(4-bromophenyl)but-3-en-1-ol → 1,3-bis((E)-4-(4-bromophenyl)but-3-enyl)-5,5-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In dichloromethane at 0 - 20℃; for 24h; Mitsunobu Displacement; Inert atmosphere;	61%

5,5-dimethylbarbituric acid (24448-94-0) + (E)-4-(4-(trifluoromethyl)phenyl)but-3-en-1-ol (173546-40-2) → 5,5-dimethyl-1,3-bis((E)-4-(4-(trifluoromethyl)phenyl)but-3-enyl)pyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In dichloromethane at 0 - 20℃; for 24h; Mitsunobu Displacement; Inert atmosphere;	60%

5,5-dimethylbarbituric acid (24448-94-0) + trans-4-(p-methoxyphenyl)-3-buten-1-ol (92587-78-5, 20840-07-7) → 1,3-bis((E)-4-(4-methoxyphenyl)but-3-enyl)-5,5-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In dichloromethane at 0 - 20℃; for 24h; Mitsunobu Displacement; Inert atmosphere;	59%

5,5-dimethylbarbituric acid (24448-94-0) + N-((1E,3E)-5-(phenylimino)penta-1,3-dienyl)benzenamine hydrochloride (1497-49-0, 13959-24-5, 61480-60-2, 120380-84-9, 149436-25-9, 149436-26-0, 149436-27-1) → N-[(1E,3E)-5-(1,3-dimethyl-2,4,6-trioxo-1,2,3,4,5,6-hexahydropyrimidin-5-ylidene)penta-1,3-dien-1-yl]-N-phenylacetamide (943923-90-8)

Conditions	Yield
With acetic anhydride	53%

5,5-dimethylbarbituric acid (24448-94-0) + (E)-4-(naphthalen-1-yl)but-3-en-1-ol1h (141171-94-0) → 5,5-dimethyl-1,3-bis((E)-4-(naphthalen-1-yl)but-3-enyl)pyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In dichloromethane at 0 - 20℃; for 24h; Mitsunobu Displacement; Inert atmosphere;	46%

5,5-dimethylbarbituric acid (24448-94-0) → methylpropionic acid ureide (23549-54-4) + 2,2-dimethylmalonic acid (595-46-0)

Conditions	Yield
With sodium hydroxide In water at 80℃; for 100h;	A 24% B 29%
With sodium hydroxide In ethanol at 25℃; Rate constant; Thermodynamic data; E(a); var. pH;

diazomethane (186581-53-3, 908094-01-9) + 5,5-dimethylbarbituric acid (24448-94-0) → tetramethylbarbituric acid (13566-66-0)

Upstream product

• 64-19-7 acetic acid 
• 57-13-6 urea 
• 5659-93-8 2,2-Dimethylmalonyl chloride 
• 595-46-0 2,2-dimethylmalonic acid 
• 67-56-1 methanol 
• 74-88-4 methyl iodide 
• 7647-01-0 hydrogenchloride 
• 7664-93-9 sulfuric acid 
• 102-09-0 bis(phenyl) carbonate 
• 6065-54-9 dimethyl dimethylmalonate 
• 1619-62-1 2,2-dimethylmalonic acid diethyl ester 
• 116070-49-6 dimethyl malonamic acid 
• 77-78-1 dimethyl sulfate 
• 41882-44-4 2,2-dimethylmalonamide 

Downstream Products

• 943923-90-8 N-[(1E,3E)-5-(1,3-dimethyl-2,4,6-trioxo-1,2,3,4,5,6-hexahydropyrimidin-5-ylidene)penta-1,3-dien-1-yl]-N-phenylacetamide 

Relevant articles and documents

Preparation method for 5,5-dimethylbarbituric acid as impurity of butalbital

The invention belongs to the technical field of pharmaceutical synthesis, and particularly relates to a preparation method for 5,5-dimethylbarbituric acid as an impurity of butalbital. In a sodium ethoxide/ethanol system, diethyl methylmalonate is dripped, and stirring is carried out; iodomethane is then dripped, and after reaction, crude 2,2-diethyl dimethylmalonate is obtained; the obtained crude 2,2-diethyl dimethylmalonate reacts with urea in a sodium ethoxide/ethanol system, and after reaction is completed, 5,5-dimethylbarbituric acid is obtained by post-processing. The raw materials of the invention are easy to obtain, the preparation method is easy to operate, the safety of reaction is high, post-processing is simple, the purity of prepared 5,5-dimethylbarbituric acid as an impurity of butalbital is high, reaching 99.40 percent or more, and the preparation method has an important guiding significance for the research of butalbital preparations.

Cpecificy of Metylation by Dimethyl Sulfate of Barbituric Acid Salts and Alkyl Derivatives

Metylation of mono- and dianionic forms of barbituric acid, its C- and N-alkyl derivatives with dimethylsulfate is studied. The methylation of monoanions occurs at the C5 carbon or O4(6) oxygen atoms, while that of dianions presumably at N1(3) nitrogen atoms. The selectivity of the dianions metylation at the nitrogen atoms increases in going from potassium to sodium and even more to lithium salts.