52328-05-9

Basic information

• Product Name: O-Methylisourea hemisulfate
• Synonyms: Bis(2-methylisouronium) sulphate;carbamimidic acid methyl ester hemisulfate;O-METHYLISOUREA HEMISULFATE;O-METHYLISOUREA HEMISULFATE SALT;O-METHYLISOUREA SULFATE;O-METHYLISOUREA SULFATE (2:1);O-METHYLPSEUDOUREA SULFATE;OMI
• CAS NO: 52328-05-9
• Molecular Formula: 2C₂H₆N₂O*H₂O₄S
• Molecular Weight: 246.24
• EINECS: 257-851-8
• Mol File: 52328-05-9.mol
• Article Data: 0

Chemical Properties

• Melting Point: 163-167 °C(lit.)
• Boiling Point: 66.9 °C at 760 mmHg
• Flash Point: 165.7 °C
• Appearance: white crystalline powder or powder
• Vapor Pressure: 2.1E-08mmHg at 25°C
• Storage Temp.: -20°C
• Solubility: H2O: 0.1 g/mL, clear
• Water Solubility: 1000 g/L (20 ºC)
• BRN: 3723107
• CAS DataBase Reference: O-Methylisourea hemisulfate(CAS DataBase Reference)
• NIST Chemistry Reference: O-Methylisourea hemisulfate(52328-05-9)
• EPA Substance Registry System: O-Methylisourea hemisulfate(52328-05-9)

Safety Data

• Hazard Codes: Xi
• Statements: 36/37/38
• Safety Statements: 24/25-36-26
• WGK Germany: 1
• F: 3
• Hazardous Substances Data: 52328-05-9(Hazardous Substances Data)

Usage

Chemical Properties

White crystals or crystalline powder

Uses

O-Methylisourea Hemisulfate was used as a reagent in the preparation of (D,L)-arginine methyl ester analogs which display antiarrhythmic actiivity. It was also used in the synthesis of ethyl [6-methyl-2-methoxy-3-(substituted phenylethanone)-4-(substituted phenyl)]-1,2,3,4-tetrahydropyrimidine-5-carboxylates which display antimicrobial activity towards mycobacterium tuberculosis, staphylococcus aureus and bacillus subtilis at varying conentration ranges.

Flammability and Explosibility

Notclassified

InChI:InChI=1/2C2H6N2O.H2O4S/c2*1-5-2(3)4;1-5(2,3)4/h2*1H3,(H3,3,4);(H2,1,2,3,4)

Synthetic route

O-methylisourea hemisulfate (52328-05-9) + 4-Chlorophenyl isothiocyanate (2131-55-7) → O-methyl-1-(p-chlorophenyl)-2-thioisobiuret (133252-65-0)

Conditions	Yield
With potassium hydroxide In acetone for 0.5h; Heating;	95%

O-methylisourea hemisulfate (52328-05-9) + 2,3,4-tri-O-acetyl-α-D-arabinopyranosyl isotyhiocyanate (62414-75-9) → C14H21N3O8S (77049-61-7)

Conditions	Yield
With triethylamine In acetonitrile for 24h; Ambient temperature;	93%

2-iminiomethylvinamidinium trichloride + O-methylisourea hemisulfate (52328-05-9) → 2-methoxy-pyrimidine-5-carbaldehyde (90905-32-1)

Conditions	Yield
With potassium hydrogencarbonate In Isopropyl acetate; water at 20℃; for 40h;	93%

O-methylisourea hemisulfate (52328-05-9) + cyclohexylamine (108-91-8) → cyclohexyl-guanidine; sulfate (6331-57-3, 14948-93-7, 62512-84-9)

Conditions	Yield
In water a) 60 deg C, 2 h, b) r.t., overnight;	91%

O-methylisourea hemisulfate (52328-05-9) + 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl isothiocyanate (14152-97-7) → C17H25N3O10S (77049-60-6)

Conditions	Yield
With triethylamine In acetonitrile for 24h; Ambient temperature;	89%

O-methylisourea hemisulfate (52328-05-9) + 2,2-diethoxy-ethanamine (645-36-3) → 2-aminoimidazole hemisulfate (1450-93-7, 36946-29-9, 42383-61-9)

Conditions	Yield
Stage #1: O-methylisourea hemisulfate; 2,2-diethoxy-ethanamine In water at 50℃; for 4h; Stage #2: With sulfuric acid In water at 100℃; for 2h; pH=2.5;	86%

O-methylisourea hemisulfate (52328-05-9) → C2H6N2O*HN5

Conditions	Yield
With barium pentazolate In methanol; water at 20℃; for 6h;	86%

O-methylisourea hemisulfate (52328-05-9) + (Z)-2-[4-(tert-Butyl-dimethyl-silanyloxy)-butyryl]-pentadec-2-enoic acid methyl ester (140175-93-5, 140175-94-6) → methyl 6-<3-<(tert-butyldimethylsilyl)oxy>propyl>-4-dodecyl-1,4-dihydro-2-methoxypyrimidine-5-carboxylate (140176-04-1)

Conditions	Yield
With sodium hydrogencarbonate In N,N-dimethyl-formamide at 60℃; for 12h;	79%

pyridine-2-carbaldehyde (1121-60-4) + O-methylisourea hemisulfate (52328-05-9) + ethyl acetoacetate (141-97-9) → C14H17N3O3

Conditions	Yield
In N,N-dimethyl-formamide at 70℃; for 3h; Inert atmosphere; Alkaline conditions;	79%

O-methylisourea hemisulfate (52328-05-9) + (E)-1-(1'-deoxy-2',3':4',5'-di-O-isopropylidene-D-xylityl)-2,3,4,4,5,5,5-heptafluoropent-2-en-1-one (698386-24-2) → 6-(1'-deoxy-2',3':4',5'-di-O-isopropylidene-D-xylityl)-5-fluoro-2-methoxy-4-(perfluoroethyl)pyrimidine

Conditions	Yield
With potassium hydroxide In dichloromethane at 20℃; for 24h;	78%

O-methylisourea hemisulfate (52328-05-9) + 4-Bromophenyl isothiocyanate (1985-12-2) → O-methyl-1-(p-bromophenyl)-2-thioisobiuret (132533-31-4)

Conditions	Yield
With potassium hydroxide In acetone Heating;	76%

5-Methylfurfural (620-02-0) + O-methylisourea hemisulfate (52328-05-9) + ethyl acetoacetate (141-97-9) → C14H18N2O4

Conditions	Yield
In N,N-dimethyl-formamide at 75℃; for 16h; Inert atmosphere; Alkaline conditions;	75.7%

Dimethyl oxalate (553-90-2) + methyl fluoroacetate (453-18-9) + O-methylisourea hemisulfate (52328-05-9) → C7H7FN2O4

Conditions	Yield
Stage #1: Dimethyl oxalate; methyl fluoroacetate With sodium methylate In toluene at 25℃; for 2h; Stage #2: O-methylisourea hemisulfate With sodium methylate In toluene at 35℃; for 8h;	70%

O-methylisourea hemisulfate (52328-05-9) + N-[3-(dimethylamino)-2-(trifluoromethyl)-2-propenylidene]-N-dimethylammonium chloride (176214-18-9) → 2-Methoxy-5-trifluoromethyl-pyrimidine

Conditions	Yield
With sodium methylate In methanol; acetonitrile for 3h; Ambient temperature;	69%

O-methylisourea hemisulfate (52328-05-9) + 2-(Benzoyloxymethylene)-4,4-(ethylenedioxy)cyclohexan-1-one (161694-48-0) → 6.6-(Ethylenedioxy)-5,6,7,8-tetrahydro-2-methoxyquinazoline (161694-49-1)

Conditions	Yield
With triethylamine In ethanol for 24h; Heating;	68%
With triethylamine In ethanol

O-methylisourea hemisulfate (52328-05-9) + (S)-1-[(10R,13S,16S,19S,22R)-19-Benzyl-13-carbamoylmethyl-22-(4-ethoxy-benzyl)-16-isopropyl-12,15,18,21,24-pentaoxo-7,8-dithia-11,14,17,20,23-pentaaza-spiro[5.19]pentacosane-10-carbonyl]-pyrrolidine-2-carboxylic acid (4-amino-butyl)-amide (99733-17-2) → (S)-1-[(10R,13S,16S,19S,22R)-19-Benzyl-13-carbamoylmethyl-22-(4-ethoxy-benzyl)-16-isopropyl-12,15,18,21,24-pentaoxo-7,8-dithia-11,14,17,20,23-pentaaza-spiro[5.19]pentacosane-10-carbonyl]-pyrrolidine-2-carboxylic acid (4-guanidino-butyl)-amide (99733-16-1)

Conditions	Yield
With sodium hydroxide In water at 0℃;	64%

(7E)-7-[(dimethylamino)methylidene]-N-methoxy-N,1-dimethyl-8-oxo-1,4,5,6,7,8-hexahydrocyclohepta[c]pyrazole-3-carboxamide (1392049-29-4) + O-methylisourea hemisulfate (52328-05-9) → N,9-dimethoxy-N,1-dimethyl-1,4,5,6-tetrahydropyrazolo[4',3':6,7]cyclohepta[1,2-d]pyrimidine-3-carboxamide (1392049-89-6)

Conditions	Yield
With potassium carbonate In acetonitrile for 16h; Reflux;	62%

ethyl 2-fluoroacetate (459-72-3) + O-methylisourea hemisulfate (52328-05-9) + oxalic acid diethyl ester (95-92-1) → C8H9FN2O4

Conditions	Yield
Stage #1: ethyl 2-fluoroacetate; oxalic acid diethyl ester With sodium methylate In toluene at 30℃; for 2h; Stage #2: O-methylisourea hemisulfate With sodium methylate In toluene at 35℃; for 8h;	62%

furfural (98-01-1) + O-methylisourea hemisulfate (52328-05-9) + ethyl acetoacetate (141-97-9) → ethyl 4-(2-furyl)-2-methoxy-6-methyl-1,4-dihydropyrimidine-5-carboxylate

Conditions	Yield
In N,N-dimethyl-formamide at 70℃; for 3h; Inert atmosphere; Alkaline conditions;	57%

O-methylisourea hemisulfate (52328-05-9) + 3,5-diamino-N-(2-aminoethyl)-6-chloropyrazine-2-carboxamide (87663-03-4) → N-(2-Guanidinoethyl)-3,5-diamino-6-chloropyrazine-2-carboxamide sulfate (147452-34-4)

Conditions	Yield
In water at 20℃; for 1.5h;	55%

allyl acetoacetate (1118-84-9) + O-methylisourea hemisulfate (52328-05-9) + 4-cyanobenzaldehyde (105-07-7) → 4-(4-cyanophenyl)-2-methoxy-6-methyl-1,4-dihydro-pyrimidine-5-carboxylic acid allyl ester (1333000-84-2)

Conditions	Yield
With sodium hydrogencarbonate In N,N-dimethyl-formamide at 70℃; Inert atmosphere;	53%

O-methylisourea hemisulfate (52328-05-9) + methyl 2-[(3,4-difluorophenyl)-methylene]-3-oxo-4-methoxybutyrate → 5-methoxycarbonyl-1,6-dihydro-2-methoxy-4-methoxymethyl-6-(3,4-difluorophenyl)pyrimidine (179482-46-3, 179482-49-6)

Conditions	Yield
With sodium hydrogencarbonate In ethanol	47%
With sodium hydrogencarbonate In ethanol

ethyl 2-cyano-4,4-diethoxybutyrate (52133-67-2) + O-methylisourea hemisulfate (52328-05-9) → 3,4-dihydro-2-methoxy-4-oxo-7H-pyrrolo<2,3-d>pyrimidine (90057-07-1)

Conditions	Yield
With sodium methylate In methanol for 4h; Heating;	46%

O-methylisourea hemisulfate (52328-05-9) + 1-isothiocyanato-4-methylbenzene (622-59-3) → O-methyl-1-(p-tolyl)-2-thioisobiuret (132533-30-3)

Conditions	Yield
With potassium hydroxide In acetone Heating;	46%

ethyl-3-(dimethylamino)-2-(phenylcarbonyl)prop-2-enoate (66129-60-0) + O-methylisourea hemisulfate (52328-05-9) → ethyl 4-phenyl-2-methoxypyrimidine-5-carboxylate (862838-05-9)

Conditions	Yield
With sodium hydrogencarbonate In 1-methyl-pyrrolidin-2-one at 80℃; for 12h;	46%

3-chloro-4H-chromen-4-one (18333-00-1) + O-methylisourea hemisulfate (52328-05-9) → 2-methoxybenzofuro[3,2-d]pyrimidine (1374216-08-6)

Conditions	Yield
With 1,10-Phenanthroline; 1,8-diazabicyclo[5.4.0]undec-7-ene; copper(I) bromide In N,N-dimethyl-formamide at 90℃; for 10h; Michael condensation; Inert atmosphere; chemoselective reaction;	46%

O-methylisourea hemisulfate (52328-05-9) + valeric acid (109-52-4) → C7H14N2O2 (847355-27-5)

Conditions	Yield
With 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine In DMF (N,N-dimethyl-formamide)	42%

benzyl 2-[(2,4-difluorophenyl)methylene]-3-oxopentanoate + O-methylisourea hemisulfate (52328-05-9) → 5-(benzyloxycarbonyl)-1,6-dihydro-2-methoxy-4-ethyl-6-(2,4-difluorophenyl)pyrimidine (191353-81-8, 191353-84-1)

Conditions	Yield
With sodium hydrogencarbonate In ethanol	42%
With sodium hydrogencarbonate In ethanol

potassium (Z)-2-cyano-2-fluoroethenolate + O-methylisourea hemisulfate (52328-05-9) → 4-amino-5-fluoro-2-methoxypyrimidine (1993-63-1)

Conditions	Yield
In methanol; water at 20℃; for 23h; Schlenk technique;	41%

O-methylisourea hemisulfate (52328-05-9) + (9E)-(+/-)-<6-(Benzoyloxymethylene)-3-methyl-7-oxobicyclo<3.3.1>non-3-en-1-yl>carbamic acid methyl ester → (11E)-(+/-)-(11-Ethylidene-5,8,9,10-tetrahydro-7-methyl-5,9-methanocyclooctapyrimidin-9-yl)carbamic acid methyl ester

Conditions	Yield
With triethylamine In N,N-dimethyl-formamide at 80℃; for 24h;	37%
With triethylamine In N,N-dimethyl-formamide

Downstream Products

• 90057-07-1 3,4-dihydro-2-methoxy-4-oxo-7H-pyrrolo<2,3-d>pyrimidine 
• 45715-47-7 N-cyclopentyl-N'-guanidine 
• 175354-56-0 2-methoxy-6-trifluoromethylpyrimidin-4-ol 
• 1993-63-1 4-amino-5-fluoro-2-methoxypyrimidine 
• 3867-74-1 butylguanidine sulfate 
• 3289-47-2 4-amino-2-methoxypyrimidine 
• 1333000-84-2 4-(4-cyanophenyl)-2-methoxy-6-methyl-1,4-dihydro-pyrimidine-5-carboxylic acid allyl ester 
• 1333015-13-6 4-(4-cyanophenyl)-2-methoxy-6-methyl-1,4-dihydropyrimidine-5-carboxylic acid methyl ester 
• 1056459-47-2 N-[amino(methoxy)methylidene]-4-[5-(3,5-dichlorophenyl)-5-trifluoromethyl-4,5-dihydroisoxazole-3-yl]-2-methylbenzoic acid amide 
• 1028725-27-0 4'-[(2-methoxy-6-oxo-4-propyl-1,6-dihydropyrimidin-5-yl)methyl]biphenyl-2-carbonitrile 
• 179482-46-3 5-methoxycarbonyl-1,6-dihydro-2-methoxy-4-methoxymethyl-6-(3,4-difluorophenyl)pyrimidine 
• 191353-81-8 5-(benzyloxycarbonyl)-1,6-dihydro-2-methoxy-4-ethyl-6-(2,4-difluorophenyl)pyrimidine 
• 186435-66-5 2-methoxy-6-amino-4-pyrimidone 
• 862838-05-9 ethyl 4-phenyl-2-methoxypyrimidine-5-carboxylate