769-42-6

Basic information

• Product Name: 1,3-Dimethylbarbituric acid
• Synonyms: AKOS B029702;1,3-DIMETHYLPYRIMIDINE-2,4,6(1H,3H,5H)-TRIONE;1,3-DIMETHYLBARBITURIC ACID;1,3-DIMETHYL-2,4,6(1H,3H,5H)-PYRIMIDINETRIONE;2,4,6(1H,3H,5H)-Pyrimidinetrione, 1,3-dimethyl-;6(1h,3h,5h)-pyrimidinetrione,1,3-dimethyl-4;Barbituric acid, 1,3-dimethyl-;N,N'-Dimethylbarbituric acid
• CAS NO: 769-42-6
• Molecular Formula: C₆H₈N₂O₃
• Molecular Weight: 156.14
• EINECS: 212-211-7
• Mol File: 769-42-6.mol
• Article Data: 25

Chemical Properties

• Melting Point: 121-123 °C(lit.)
• Boiling Point: 228.1 °C at 760 mmHg
• Flash Point: 95.3 °C
• Appearance: White/cream/pale yellow/Crystalline Powder
• Density: 1.322 g/cm³
• Vapor Pressure: 0.0746mmHg at 25°C
• Refractive Index: 1.511
• Storage Temp.: -20°C Freezer
• Solubility: hot water: soluble0.5g/10 mL, clear, colorless to faintly yellow
• PKA: pK1:4.68(+1) (25°C)
• Water Solubility: Soluble in water.
• BRN: 139810
• CAS DataBase Reference: 1,3-Dimethylbarbituric acid(CAS DataBase Reference)
• NIST Chemistry Reference: 1,3-Dimethylbarbituric acid(769-42-6)
• EPA Substance Registry System: 1,3-Dimethylbarbituric acid(769-42-6)

Safety Data

• Hazard Codes: Xn
• Statements: 22-41
• Safety Statements: 26-36/39
• WGK Germany: 3
• TSCA: Yes
• Hazardous Substances Data: 769-42-6(Hazardous Substances Data)

Usage

Chemical Properties

Yellow or brownish powder

Uses

Different sources of media describe the Uses of 769-42-6 differently. You can refer to the following data:
1. 1,3-Dimethylbarbituric acid is used as a catalyst in the Knoevenagel condensation of a series of aromatic aldehydes. It is also used in the synthesis of 5-aryl-6-(alkyl- or aryl-amino)-1,3-dimethylfuro [2,3-d]pyrimidine derivatives and enantioselective synthesis of isochromene pyrimidinedione derivatives.
2. 1,3-Dimethyl Barbituric Acid (Urapidil Impurity 4) is a derivative of Barbituric acid. All of the barbituric acid derivatives which have been reported to have pronounced hypnotic activity are disubstituted in the 5-position.

General Description

1,3-Dimethylbarbituric acid (1,3-Dimethyl-2,4,6(1H,3H,5H)-pyrimidinetrione) is an active methylene compound. It undergoes hollow Pd6 water-soluble cage, [{(tmen)Pd}6(timb)4](NO3)12 (tmen= N,N,N′,N′-tetramethylethylenediamine, timb=1,3,5-tris(1-imidazolyl)benzene)-catalyzed Knoevenagel condensation reaction with pyrene-1-carboxaldehyde. It undergoes self-sorted Pd7 molecular boat having an internal nanocavity (catalyst)-assisted Knoevenagel condensation reaction with various aromatic aldehydes. It has been synthesized by reacting 1,3-dimethylurea, malonic acid and acetic anhydride in acetic acid. It is widely used for the synthesis of various synthetic intermediates and heterocyclic compounds.

Purification Methods

Crystallise the acid from water and sublime it in a vacuum. Also purify it by dissolving 10g in 100mL of boiling CCl4/CHCl3 (8:2) (1g charcoal), filtering and cooling to 25o. Dry it in vacuo [Kohn et al. Anal Chem 58 3184 1986]. [Beilstein 24 III/IV 1875.]

InChI:InChI=1/C6H8N2O3/c1-7-4(9)3-5(10)8(2)6(7)11/h3H2,1-2H3

Synthetic route

5,5-dibromo-1,3-dimethyl-2,4,6(1H,3H,5H)-pyrimidinetrione (56983-59-6) + phenol (108-95-2) → 1,3-dimethylbarbituric acid (769-42-6) + 4-bromo-phenol (106-41-2)

Conditions	Yield
at 100℃; for 48h;	A 81% B 91%
at 100℃; for 48h;	A 81% B n/a

6-methoxy-1,3-dimethyluracil (4097-20-5) → 1,3-dimethylbarbituric acid (769-42-6)

Conditions	Yield
With hydrogenchloride In ethanol for 0.833333h; Heating;	90%

N,N'-Dimethylurea (96-31-1) + malonic acid (141-82-2) → 1,3-dimethylbarbituric acid (769-42-6)

Conditions	Yield
In acetic anhydride	85%
With acetic anhydride at 90℃; 1) 65 deg C, 30 min; 2) 90 deg C, 4 h;	68%
With acetic anhydride
With water

1,3-dimethylthiobarbituric acid (3158-63-2) → 1,3-dimethylbarbituric acid (769-42-6)

Conditions	Yield
With trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxolane; water; potassium hydroxide In acetonitrile at 20℃; for 0.25h;	80%

dimethyl sulfate (77-78-1) + C11H8N2O3(2-)*2Li(1+) → 1,3-dimethylbarbituric acid (769-42-6) + 6-methoxy-1,3-dimethyluracil (4097-20-5) + N-methyl-N'-benzyl-barbituric acid (82922-17-6)

Conditions	Yield
In water at 10℃; Yields of byproduct given;	A n/a B n/a C 77%

dimethyl sulfate (77-78-1) + C5H4N2O3(2-)*2Li(1+) → 1,3-dimethylbarbituric acid (769-42-6)

Conditions	Yield
In water at 10℃;	76%

methylamine (74-89-5) + 3-methyl-6-chloro-3,4-dihydro-2H-1,3-oxazine-2,4-dione (30914-82-0) → 1,3-dimethylbarbituric acid (769-42-6)

Conditions	Yield
In tetrahydrofuran at 0 - 5℃; for 0.25h;	74%
With acetic acid In tetrahydrofuran; water for 0.25h;	45%
With acetic acid In tetrahydrofuran; water for 0.25h; Mechanism;	45%

1,3-dimethyl-5-(2-oxo-2-phenylethylidene)-pyrimidine-2,4,6(1H,3H,5H)-trione (1063626-88-9) + 4-Bromo-benzene-1,2-diamine (1575-37-7) → 1,3-dimethylbarbituric acid (769-42-6) + 6-bromo-2-phenyl-quinoxaline (898825-98-4)

Conditions	Yield
In methanol for 1h; Heating;	A n/a B 68%

1,3-dimethyl-5-(2-oxo-2-phenylethylidene)-pyrimidine-2,4,6(1H,3H,5H)-trione (1063626-88-9) + 1,2-diamino-benzene (95-54-5) → 1,3-dimethylbarbituric acid (769-42-6) + 2-phenylquinoxaline (5021-43-2)

Conditions	Yield
In methanol for 1h; Heating;	A n/a B 64%

1,3-Dimethyl-6-chlorouracil (6972-27-6) → 1,3-dimethylbarbituric acid (769-42-6) + 5-chloro-9,11-diazapentacyclo[6.4.0.01,3.02,6.04,8]dodecane-10,12-dione

Conditions	Yield
With trifluoroacetic acid In benzene at -25℃; for 3h; Irradiation;	A 50% B 7.5%

N,N'-Dimethylurea (96-31-1) + diethyl malonate (105-53-3) → 1,3-dimethylbarbituric acid (769-42-6)

Conditions	Yield
With ethanol; sodium In neat liquid at 60℃; for 0.5h; Reagent/catalyst; Sonication;	47%
With sodium methylate In methanol 1.) 10 min, reflux, 2.) 6 h, 110 deg C; Yield given;
With sodium ethanolate In ethanol Reflux;

dimethyl sulfate (77-78-1) + C4H2N2O3(2-)*2Li(1+) → 1,3-dimethylbarbituric acid (769-42-6)

Conditions	Yield
In water at 10℃;	42%

1,3-Dimethyl-6-chlorouracil (6972-27-6) + benzene (71-43-2) → 1,3-dimethylbarbituric acid (769-42-6) + 1,3-dimethylcyclooctapyrimidine-2,4-dione (134886-54-7) + 5-chloro-1,3-dimethyl-4b,5,7a,8-tetrahydro-(4bα,5α,8α)-pentaleno<1,2-e>pyrimidine-2,4-dione + 7-chloro-1,3-dimethyl-4b,7,7a,8-tetrahydro-(4bα,7α,7aα)-pentaleno<1,2-e>pyrimidine-2,4-dione + 5-chloro-9,11-diazapentacyclo[6.4.0.01,3.02,6.04,8]dodecane-10,12-dione

Conditions	Yield
With trifluoroacetic acid at -25℃; for 1h; Product distribution; Mechanism; Irradiation; var. time, temp.;	A 24.5% B 4.3% C 2.8% D 2.1% E 5.9%

BARBITURIC ACID (67-52-7) + furan-2,3,5(4H)-trione pyridine (1:1) + dimethyl sulfate (77-78-1) → 1,3-dimethylbarbituric acid (769-42-6)

BARBITURIC ACID (67-52-7) + dimethyl sulfate (77-78-1) → 1,3-dimethylbarbituric acid (769-42-6)

Conditions	Yield
With sodium hydroxide

6-Amino-1,3-dimethylbarbituric acid (6642-31-5) → 1,3-dimethylbarbituric acid (769-42-6)

Conditions	Yield
With hydrogenchloride

1,1-Dimethylurea (598-94-7) + cyanoacetic acid chloride (16130-58-8) → 1,3-dimethylbarbituric acid (769-42-6) + 6-Amino-1,3-dimethylbarbituric acid (6642-31-5)

1,1-Dimethylurea (598-94-7) + malonic acid (141-82-2) → 1,3-dimethylbarbituric acid (769-42-6)

Conditions	Yield
With acetic anhydride; acetic acid at 60 - 90℃;

5,5-dichloro-1,3-dimethyl-2,4,6(1H,3H,5H)-pyrimidinetrione (21544-73-0) → 1,3-dimethylbarbituric acid (769-42-6)

Conditions	Yield
With phosphonium iodide; hydrogen iodide
With palladium on activated charcoal; acetone Hydrogenation;

5,5-dibromo-1,3-dimethyl-2,4,6(1H,3H,5H)-pyrimidinetrione (56983-59-6) → 1,3-dimethylbarbituric acid (769-42-6)

Conditions	Yield
With hydrogenchloride; tin(ll) chloride

1,1-Dimethylurea (598-94-7) + malonoyl dichloride (1663-67-8) → 1,3-dimethylbarbituric acid (769-42-6)

Conditions	Yield
With trichlorophosphate

3-Bromopropionyl chloride (15486-96-1) + 6-(1-methylhydrazino)uracil (4318-53-0) → 1,3-dimethylbarbituric acid (769-42-6) + N-(1,3-dimethyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-6-yl)-N-methyl-N'-acrylolylhydrazine + 1,3-Dimethyl-6-[methyl-(2-oxo-azetidin-1-yl)-amino]-1H-pyrimidine-2,4-dione

Conditions	Yield
With potassium hydroxide; N-benzyl-N,N,N-triethylammonium chloride In dichloromethane Yield given. Yields of byproduct given;

N-(1,3-dimethyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-6-yl)-N-methyl-N'-acrylolylhydrazine → 1,3-dimethylbarbituric acid (769-42-6) + Acrylic acid N'-methyl-hydrazide

Conditions	Yield
With sodium hydrogencarbonate In dichloromethane for 168h;

2-Bromo-acrylic acid N'-(1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydro-pyrimidin-4-yl)-N'-methyl-hydrazide → 1,3-dimethylbarbituric acid (769-42-6) + 2-Bromo-acrylic acid N'-methyl-hydrazide

Conditions	Yield
With sodium hydrogencarbonate In dichloromethane for 168h;

2,3-dibromo-propionyl chloride (18791-02-1) + 6-(1-methylhydrazino)uracil (4318-53-0) → 1,3-dimethylbarbituric acid (769-42-6) + 2-Bromo-acrylic acid N'-(1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydro-pyrimidin-4-yl)-N'-methyl-hydrazide + 6-[(3-Bromo-2-oxo-azetidin-1-yl)-methyl-amino]-1,3-dimethyl-1H-pyrimidine-2,4-dione

Conditions	Yield
With potassium hydroxide; N-benzyl-N,N,N-triethylammonium chloride In dichloromethane Yield given. Yields of byproduct given;

urapidil (34661-75-1) → 1,3-dimethylbarbituric acid (769-42-6) + 3-(4-(2-methoxyphenyl)piperazin-1-yl)propylamine (20529-23-1)

Conditions	Yield
With hydrogenchloride at 79.9℃; Rate constant; Kinetics; Mechanism; var. pH and temp.;

5-(2',4'-dinitrobenzylidene)-1,3-dimethylbarbituric acid (110449-10-0) → 1,3-dimethylbarbituric acid (769-42-6) + 2,4-dinitrobenzaldehyde (528-75-6)

Conditions	Yield
With sodium chloride In water at 25℃; Equilibrium constant;

dimethyl sulfate (77-78-1) + C4H2N2O3(2-)*2K(1+) → 1,3-dimethylbarbituric acid (769-42-6) + 6-methoxy-1,3-dimethyluracil (4097-20-5) + 1-phenyl-pyrimidine-2,4,6-trione (15018-50-5)

Conditions	Yield
In water at 10℃; Yield given. Yields of byproduct given;

dimethyl sulfate (77-78-1) + C4H2N2O3(2-)*2Na(1+) → 1,3-dimethylbarbituric acid (769-42-6) + 6-methoxy-1,3-dimethyluracil (4097-20-5) + 1-phenyl-pyrimidine-2,4,6-trione (15018-50-5)

Conditions	Yield
In water at 10℃; Yield given. Yields of byproduct given;

dimethyl sulfate (77-78-1) + C5H4N2O3(2-)*2K(1+) → 1,3-dimethylbarbituric acid (769-42-6) + 1,3,5-trimethylbarbituric acid (7358-61-4) + 6-methoxy-1,3-dimethyluracil (4097-20-5)

Conditions	Yield
In water at 10℃; Yield given. Yields of byproduct given;

1,3-dimethylbarbituric acid (769-42-6) + 4-hydroxy-benzaldehyde (123-08-0) → 1,3-dimethyl-5-(4-hydroxybenzylidene)pyrimidine-2,4,6(1H,3H,5H)-trione (57270-80-1)

Conditions	Yield
at 20℃; for 1h; Knoevenagel condensation;	100%
In water for 0.333333h; Knoevenagel Condensation; Milling;	97%
With iron oxide; ammonium acetate In ethanol; water for 0.333333h; Reagent/catalyst; Knoevenagel Condensation; Reflux;	91%

diazomethane (186581-53-3, 908094-01-9) + 1,3-dimethylbarbituric acid (769-42-6) → 6-methoxy-1,3-dimethyluracil (4097-20-5)

Conditions	Yield
In methanol at 20℃; Product distribution; further solvent, various ratio of educts;	100%
In diethyl ether at 20℃; for 24h;
In diethyl ether at 20℃; for 24h; oth. solvents;	100 % Spectr.

1,3-dimethylbarbituric acid (769-42-6) → 1,3-dimethyl-5-nitro-pyrimidin-2,4,6(1H,3H,5H)-trione (14305-99-8)

Conditions	Yield
With Nitrogen dioxide under 225.02 Torr; for 4h;	100%
Stage #1: 1,3-dimethylbarbituric acid With acetic acid In water at 75℃; for 0.5h; Stage #2: With sodium nitrite at 20℃; for 1h;	90%
With sulfuric acid; nitric acid In water at 20℃;

1,3-dimethylbarbituric acid (769-42-6) + 4-dimethylamino-benzaldehyde (100-10-7) → 5-(4-dimethylamino-benzylidene)-1,3-dimethyl-pyrimidine-2,4,6-trione (57270-81-2)

Conditions	Yield
In methanol Knoevenagel Condensation; Reflux;	100%
With Cyclohexyl isocyanide In N,N-dimethyl-formamide at 25℃; for 0.5h; Knoevenagel condensation;	95%
In ethanol; water at 60℃; for 60h; Knoevenagel Condensation;	92%

1,3-dimethylbarbituric acid (769-42-6) + 4,6-dimethyl-1H-pyrazolo[3,4-b]pyridine-3-diazonium nitrate → 1,3-dimethyl-5-{(4,6-dimethyl-1H-pyrazolo[3,4-b]pyridin-3-yl)hydrazono}pyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With trimethylamine at 20℃; under 375.03 Torr; for 12h;	100%

1,3-dimethylbarbituric acid (769-42-6) + 7,9-dimethylcyclohepta[b]pyrimido[5,4-d]furan-8(7H),10(9H)-dionylium tetrafluoroborate → 5,5-bis-(1,3-dimethyl-2,4-dioxo-1,3,4,7-tetrahydro-2H-10-oxa-1,3-diaza-benzo[a]azulen-7-yl)-1,3-dimethyl-pyrimidine-2,4,6-trione

Conditions	Yield
With triethylamine In acetonitrile at 20℃; for 2h;	100%

1,3-dimethylbarbituric acid (769-42-6) + 2-hydroxynaphthalene-1-carbaldehyde (708-06-5) → 8,10-dimethyl-12-(1,3-dimethyl-2,4,6(1H,3H,5H)-trioxopyrimidin-5-yl)naphtho[1',2':5,6]pyrano[2,3-d]pyrimidine-9,11(8H,10H)-dione

Conditions	Yield
In ethanol for 2h; Heating;	100%

C17H22NFO + 1,3-dimethylbarbituric acid (769-42-6) → C23H28O3FN3

Conditions	Yield
In butan-1-ol at 75℃; for 20h;	100%

1,3-dimethylbarbituric acid (769-42-6) + 2-(pyrrolidin-1-yl)quinoline-3-carbaldehyde (938138-99-9) → (+/-)-1',3'-dimethyl-1,2,3,3a-tetrahydro-2'H,5H-spiro[benzo[g]pyrrolo[1,2-a]-1,8-naphthyridine-4,5'-pyrimidine]-2',4',6'(1'H,3'H)-trione (918937-87-8)

Conditions	Yield
In butan-1-ol at 75℃; for 30h;	100%

1,3-dimethylbarbituric acid (769-42-6) + 3-fluoro-2-(morpholin-4-yl)benzaldehyde (736991-35-8) → (+/-)-10-fluoro-1',3'-dimethyl-1,2,4,4a-tetrahydro-2'H,6H-spiro[1,4-oxazino-5,5'-pyrimidine]-2',4',6'(1'H,3'H)-trione (1028090-38-1)

Conditions	Yield
In butan-1-ol at 100℃; for 6h;	100%

1,3-dimethylbarbituric acid (769-42-6) + 6-(4-methylpiperazin-1-yl)[1,3]dioxolo[4,5-g]quinoline-7-carbaldehyde (1028090-24-5) → (+/-)-1',3,3'-trimethyl-2,3,4,4a-tetrahydro-1H,2'H,6H-spiro[1,3-benzodioxolo[5,6-g]pyrazino[1,2-a]-1,8-naphthyridine-5,5'-pyrimidine]-2',4',6'(1'H,3'H) trione (1028090-50-7)

Conditions	Yield
In butan-1-ol at 75℃; for 30h;	100%

1,3-dimethylbarbituric acid (769-42-6) + 4-nitrobenzaldehdye (555-16-8) + malononitrile (109-77-3) → 7‑amino‑5‑(4‑nitrophenyl)‑1,3‑dimethyl‑2,4‑dioxo‑1,3,4,5‑tetrahydro‑2H‑pyrano[2,3‑d]pyrimidine‑6‑carbonitrile (496971-17-6)

Conditions	Yield
With [Zn2(amino-1,4-benzenedicarboxylate)2(2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene)]*3DMF In water for 1h; Reflux; Green chemistry;	100%
With water glass In neat (no solvent) for 0.25h; Milling; Heating;	97%
In water at 70℃; for 0.833333h; Green chemistry;	97%

1,3-dimethylbarbituric acid (769-42-6) + 2-nitro-benzaldehyde (552-89-6) + malononitrile (109-77-3) → 7‑amino‑5‑(2‑nitrophenyl)‑1,3‑dimethyl‑2,4‑dioxo‑1,3,4,5‑tetrahydro‑2H‑pyrano[2,3‑d]pyrimidine‑6‑carbonitrile (298219-13-3)

Conditions	Yield
With [Zn2(amino-1,4-benzenedicarboxylate)2(2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene)]*3DMF In water for 1h; Reflux; Green chemistry;	100%
In water at 70℃; for 0.75h; Green chemistry;	95%
With polyethylene glycol-stabilized Ni(0) nano particles In ethylene glycol at 20℃; for 0.0833333h;	93%
With L-prolinium nitrate In water at 20℃; for 0.0666667h; Temperature; Sonication; Green chemistry;	93%
With water glass In neat (no solvent) for 0.416667h; Milling; Heating;	83%

1,3-dimethylbarbituric acid (769-42-6) + 2-(N,N-diethylaminomethyl)benzaldehyde (79422-67-6) → C18H23N3O3 (1582807-51-9)

Conditions	Yield
In ethanol at 20℃; for 1h; Inert atmosphere;	100%

nitrostyrene (5153-67-3) + 1,3-dimethylbarbituric acid (769-42-6) → 1,3-dimethyl-5-(2-nitro-1-phenylethyl)pyrimidine-2,4,6(1H,3H,5H)-trione

Conditions	Yield
With 2Zn(2+)*2NO3(1-)*2C3H7NO*2Y(3+)*4C14H11NO3(2-) In ethanol; water at 20℃; for 0.25h; Reagent/catalyst; Michael Addition;	100%
With water; diethylamine at 20℃; for 1h; Reagent/catalyst; Time; Michael Addition; Green chemistry;	99%

1,3-dimethylbarbituric acid (769-42-6) + 3-nitro-benzaldehyde (99-61-6) + malononitrile (109-77-3) → 7-amino-1,3-dimethyl-5-(3-nitrophenyl)-2,4-dioxo-1,3,4,5-tetrahydro-2H-pyrano [2,3-d]pyrimidine-6-carbonitrile (1072002-79-9)

Conditions	Yield
With [Zn2(amino-1,4-benzenedicarboxylate)2(2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene)]*3DMF In water for 1h; Reflux; Green chemistry;	100%
With L-prolinium nitrate In water at 20℃; for 0.0666667h; Temperature; Sonication; Green chemistry;	95%
With urea-based ionic liquid stabilized on silica-coated Fe3O4 magnetic nanoparticles In neat (no solvent) at 60℃; for 0.5h; Green chemistry;	94%

1,3-dimethylbarbituric acid (769-42-6) + terephthalaldehyde, (623-27-8) + dimedone (126-81-8) + diethylamine (109-89-7) → 4-((6-hydroxy-1,3-dimethyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-5-yl)(2-hydroxy-4,4-dimethyl-6-oxocyclohex-1-en-1-yl)methyl)benzaldehyde diethylaminium salt (1621511-22-5)

Conditions	Yield
In water at 20℃; Inert atmosphere;	100%
With water at 20℃; Green chemistry;	90%

1,3-dimethylbarbituric acid (769-42-6) + 4-methyl-benzaldehyde (104-87-0) + diethylamine (109-89-7) → 5,5'-(p-tolylmethylene)bis(1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione) diethylaminium salt (1621510-97-1)

Conditions	Yield
In water at 20℃; Inert atmosphere;	100%
With water; dimedone at 20℃; Green chemistry;	97%

1,3-dimethylbarbituric acid (769-42-6) + 4-nitrobenzaldehdye (555-16-8) + diethylamine (109-89-7) → 5,5'-((4-nitrophenyl)methylene)bis(1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione) diethylaminium salt (1621510-98-2)

Conditions	Yield
In water at 20℃; Inert atmosphere;	100%
With water; dimedone at 20℃; Green chemistry;	87%

1,3-dimethylbarbituric acid (769-42-6) + 4-methoxy-benzaldehyde (123-11-5) + diethylamine (109-89-7) → 5,5'-((4-methoxyphenyl)methylene)bis(1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione) diethylaminium salt (1621510-99-3)

Conditions	Yield
In water at 20℃; Inert atmosphere;	100%
With water; dimedone at 20℃; Green chemistry;	90%

1,3-dimethylbarbituric acid (769-42-6) + m-bromobenzoic aldehyde (3132-99-8) + diethylamine (109-89-7) → 5,5'-((3-bromophenyl)methylene)bis(1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione) diethylaminium salt (1621511-01-0)

Conditions	Yield
In water at 20℃; Inert atmosphere;	100%
With water; dimedone at 20℃; Green chemistry;	92%

1,3-dimethylbarbituric acid (769-42-6) + 4-hydroxy-benzaldehyde (123-08-0) + diethylamine (109-89-7) → 5,5'-((4-hydroxyphenyl)methylene)bis(6-hydroxy-1,3-dimethylpyrimidine-2,4(1H,3H)-dione) diethylaminium salt (1621511-03-2)

Conditions	Yield
In water at 20℃; Inert atmosphere;	100%
With water; dimedone at 20℃; Green chemistry;	88%

1,3-dimethylbarbituric acid (769-42-6) + diethylamine (109-89-7) + m-tolyl aldehyde (620-23-5) → 5,5'-(3-tolylmethylene)bis(1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione) diethylaminium salt (1621511-05-4)

Conditions	Yield
In water at 20℃; Inert atmosphere;	100%
With water; dimedone at 20℃; Green chemistry;	97%

1,3-dimethylbarbituric acid (769-42-6) + β-naphthaldehyde (66-99-9) + diethylamine (109-89-7) → 5,5'-(naphthalen-2-ylmethylene)bis(1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione) diethylaminium salt (1621511-07-6)

Conditions	Yield
In water at 20℃; Inert atmosphere;	100%
With water; dimedone at 20℃; Green chemistry;	94%

1,3-dimethylbarbituric acid (769-42-6) + terephthalaldehyde, (623-27-8) + diethylamine (109-89-7) → 4-(bis(6-hydroxy-1,3-dimethyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-5-yl)methyl)benzaldehyde diethylaminium salt (1621511-09-8)

Conditions	Yield
In water at 20℃; Inert atmosphere;	100%
With water; dimedone at 20℃; Green chemistry;	92%

1,3-dimethylbarbituric acid (769-42-6) + C10H16N2O4 (95239-02-4) → di-tert-butyl 2,2’-[(1,3-dimethyl-2,4,6-trioxohexahydropyrimidine-5,5-diyl)bis(4-methoxy-4-oxobut-3-yl-2-ylidene)]bis(hydrazine-1-carboxylate)

Conditions	Yield
With N-ethyl-N,N-diisopropylamine In dichloromethane at 20℃; for 3h; Michael Addition;	100%

1,3-dimethylbarbituric acid (769-42-6) + 4-methoxy-benzaldehyde (123-11-5) + dimedone (126-81-8) + diethylamine (109-89-7) → C22H26N2O6*C4H11N

Conditions	Yield
In water at 20℃; Inert atmosphere;	100%

1,3-dimethylbarbituric acid (769-42-6) + m-bromobenzoic aldehyde (3132-99-8) + dimedone (126-81-8) + diethylamine (109-89-7) → C21H23BrN2O5*C4H11N

Conditions	Yield
In water at 20℃; Inert atmosphere;	100%

1,3-dimethylbarbituric acid (769-42-6) + 4-hydroxy-benzaldehyde (123-08-0) + dimedone (126-81-8) + diethylamine (109-89-7) → C21H24N2O6*C4H11N

Conditions	Yield
In water at 20℃; Inert atmosphere;	100%

1,3-dimethylbarbituric acid (769-42-6) + 4-methyl-benzaldehyde (104-87-0) + dimedone (126-81-8) + diethylamine (109-89-7) → C22H26N2O5*C4H11N

Conditions	Yield
In water at 20℃; Inert atmosphere;	100%

Upstream product

• 67-52-7 BARBITURIC ACID 
• 77-78-1 dimethyl sulfate 
• 6642-31-5 6-Amino-1,3-dimethylbarbituric acid 
• 96-31-1 N,N'-Dimethylurea 
• 141-82-2 malonic acid 
• 74-89-5 methylamine 
• 30914-82-0 3-methyl-6-chloro-3,4-dihydro-2H-1,3-oxazine-2,4-dione 
• 18791-02-1 2,3-dibromo-propionyl chloride 
• 4318-53-0 6-(1-methylhydrazino)uracil 
• 58378-09-9 1,3,1',3'-tetramethylhydurilic acid 
• 3158-63-2 1,3-dimethylthiobarbituric acid 
• 15486-96-1 3-Bromopropionyl chloride 
• 598-94-7 1,1-Dimethylurea 
• 1663-67-8 malonoyl dichloride 

Downstream Products

• 14305-99-8 1,3-dimethyl-5-nitro-pyrimidin-2,4,6(1H,3H,5H)-trione 
• 959833-62-6 1,3-dimethyl-5-[1-(4-methoxyphenyl)-3-oxo-3-phenylpropyl]pyrimidine-2,4,6(1H,3H,5H)-trione 
• 54890-67-4 1,3-dimethyl-5-(3-oxo-1,3-diphenylpropyl)pyrimidine-2,4,6(1H,3H,5H)-trione 
• 223718-61-4 6-(benzyloxycarbonyl)amino-1,3-dimethyl-2,4-dioxo-1,2,3,4-tetrahydro-7H-pyrano<2,3-d>pyrimidin-7-one 
• 314272-06-5 6-phenyl-1,3-dimethylfuro[2,3-d]pyrimidine-2,4(1H,3H)-dione 
• 7358-61-4 1,3,5-trimethylbarbituric acid 

Relevant articles and documents

Kinetics of Electrophilic Alkylations of Barbiturate and Thiobarbiturate Anions

Second-order rate constants (k2) of the reactions of various barbiturate anions such as the parent barbiturate, 1,3-dimethylbarbiturate, 2-thiobarbiturate, and 1,3-diethyl-2-thiobarbiturate with diarylcarbenium ions and Michael acceptors have b

Ultrasound-assisted rapid synthesis of 2-aminopyrimidine and barbituric acid derivatives

Novel, inexpensive, and relatively expeditious procedure to achieve the synthesis of different 2-aminopyrimidine and barbituric acid derivatives is presented here, starting from readily available compounds such as guanidine hydrochloride, urea, 1,3-dialkylurea, or thiourea. Under ultrasonic irradiation, base-driven (Na2CO3, NaOH, or NaOC2H5) heterocyclization reactions of the aforementioned substrates with diethyl malonate, diethyl-2-alkyl malonate, pentane-2,4-dione, or ethyl-3-oxobutanoate yielded corresponding products. Significant advantages of this sonochemical synthetic protocol with regard to the conventional thermal methods include easy reaction setup and work-up steps, reasonably mild conditions, shorter reaction times (～30 min) and comparably high product yields. The characterization of the synthesized compounds was based on melting points, FT-IR, GC-MS, 1H-NMR techniques, and the obtained data were also checked from the previously published studies.

Selective and facile oxidative desulfurization of thioureas and thiobarbituric acids with singlet molecular oxygen generated from trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxolane

An efficient and facile procedure using trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxolane has been developed for oxidative desulfurization of thioureas and thiobarbituric acids. The reactions proceeded smoothly very fast under mild conditions in basic media at room temperature to afford the respective ureas in excellent yields. Simple procedure and work up, mild conditions, high yields, short reaction times, use of highly potent and non-toxic oxidant are the main merits of the present method.