Potassium acetate cyanate

Fluproquazone (97) contains a 2-quinazolinone nucleus and is found to be an analgetic agent useful in mild to moderate pain. One of the preparations involves reaetion of 2-isopropylamino-4-methyl-4 -fluoro-benzophenone (96) with potassium cyanate in hot acetic acid [27],... 

Early studies on 4(5)-aminoimidazole (25 R=H) gave a stable urea derivative (37BJ488). Thus, treatment of a solution of 4(5)-aminoimidazole (25 R = H), made slightly acidic by addition of acetic acid, with potassium cyanate gave AMmidazol-4-yl-urea (31) (8%). TV-Imidazol-4-yl-urea (31) was similarly obtained using the dihydrochloride salt of 4(5)-aminoimidazole (25 R = H) (41MI1). 

The synthesis of a C-labelled version of naratriptan (3b) is highlighted in Scheme The indole ring of naratriptan hydrochloride (3) was oxidatively cleaved using sodium periodate to give ketoformanilide 45. Cyanation of 45 with potassium [ C]cyanide in aqueous ethanol gave the intermediate amidine 46, which was reduced directly with NaBH4 in acetic acid to afford C-labelled naratriptan (3b), which was isolated as the hydrochloride salt. 

Potassium cyanate [590-28-3] M 81.1. Common impurities include ammonia and bicarbonate ion (from hydrolysis). Purified by preparing a saturated aqueous solution at 50°, neutralising with acetic acid, filtering, adding two volumes of EtOH and keeping for 3-4h in an ice bath. (More EtOH can lead to co-precipitation of KHCO3.) Filtered, washed with EtOH and dried rapidly in a vacuum desiccator (P2O5). The process is repeated [Vanderzee and Meyers JCS 65 153 1961. ... 

In conductive inks for continuous ink-jet printers salts such as lithium acetate and potassium cyanate are added to adjust the specific conductivity. 

A solution of potassium cyanate (11 mg) in water (1.36 ml) was added portionwise during 1 hour to a solution of the above hydrazide (118 mg) in a 20 1 v/v mixture of water and acetic acid (10 ml). The mixture was freeze-dried and the residue was purified by reverse-phase column chromatography (Dynamax 60 ANG, C18, 1 inch diameter) using a gradient of 10% to 40% by volume of acetonitrile in water containing 0.1% trifluoroacetic acid. There was thus obtained goserelin (100 mg, 25% yield overall), the structure of which was confirmed by mass spectroscopy. 

The structure of Co(acac)3 is a distorted octahedron, Co—O = 1.888(4) A, Z OCoO = 96.5°.355 Thermal decomposition of Co(acac)3 to Co(acac)2 has been reported, and the mass spectra of Co(acac)2,oxine and Co(acac)(oxine)2 have been studied.356 Acetic acid and [Co(CO)3L2]+ (L = bipy or phen) in alcohol-water react to form [Co(acac)L2]2+ and [Co(acac)2L] +. 357 The cis-trans isomerization of [Co(acac)2(py)X] (X = N3, N02, NCO, or CN) has been examined and the trans - cis rate is N3 > NCO > N02 > CN.358 Potassium cyanate reacts with Co(acac)2 in aqueous solution in the presence of pyridine and hydrogen peroxide to form [Co-(acac)2(NCOXpy)].358 An extension of this work to KNCS produced trans-[Co(acac)2-(SCN)(py)]. On standing this complex undergoes linkage isomerism to the isothio-cyanato analogue, whilst under reflux cis-[Co(acac)2(NCSXpy)] forms.359... 

Preparation from Hydrazine Sulfate. Sixty-five grams of hydrazine sulfate (0.5 mol) is added to a mixture of 30 g. of glacial acetic acid (0.5 mol) in 1000 ml. of water. Eighty-nine grams of potassium cyanate (1.1 mol) dissolved in 300 ml. of water is added to this solution portion-wise with constant stirring. Considerable gas evolution takes place, and the temperature rises to about 40°. The acetic acid serves to adjust the final pH to approximately 4.8. 

Ninety-nine grams of carbohydrazide (1.10 mols) is dissolved in a solution containing 120 g. of glacial acetic acid (2.00 mols) and 1000 ml. of water. To this, a solution of 81 g. of potassium cyanate (1.00 mol) in 350 ml. water is added dropwise over a period of about 2 hours. The mixture is digested at room temperature for 5 hours. The precipitate is then removed by filtration and washed very thoroughly with water, alcohol, and ether. The dry product weighs approximately 115 g. (86%) and melts with decomposition at 227 to 228°. 

Pellizzari and Roncagliolo2 prepared this compound by reaction of carbohydrazide in dilute acetic acid with 2 mols of potassium cyanate and also by condensation of carbohydrazide- A-carboxamide hydrochloride with 1 mol of cyanate. The former procedure does not give a pure product, probably because of the preferential formation of the less soluble carbohydrazide-A-carboxamide. The latter reacts wjth hydrochloric acid to form the hydrochloride, which is water-soluble. Prior condensation of carbohydrazide to form the A-carboxamide is advantageous, since the hydrochloride of this compound will undergo further reaction with cyanate to give the desired product by precipitation from water. When the procedure outlined below is followed, it is not necessary to recrystallize the carbohydrazide-A, A -dicarboxamide unless an extremely pure material is desired. 

Cobalt acetate solution When the reagent is added to a concentrated solution of potassium cyanate, a blue colouration, due to tetracyanatocobaltate(II) ions, [Co(OCN)4]2- is produced. The colour is stabilized and intensified somewhat by the addition of ethanol. 

The earliest method of this type was the old Marckwald synthesis (1] in which a suitable a-aminocarbonyl compound is cyclized with cyanate, thiocyanate or isothiocyanatc. More recent modifications have employed the acetals of the a-amino aldehyde or ketone or an a-amino acid ester. The two-carbon fragment can also be provided by cyanamide, a thioxamate, a carbodiimidc or an imidic ester. When cyanates, thiocyanates or isothiocyanates are used, the imidazolin-2-ones or -2-thiones (1) are formed initially, but they can be converted into 2-unsubstituted imidazoles quite readily by oxidative or dehydrogenative means (Scheme 4.1.1). The chief limitations of the method arc the difficulty of making some a-aminocarbonyls and the very limited range of 2 substituents which are possible in the eventual imidazole products. The method is nonetheless valuable and widely used, and typically condenses the hydrochloride of an a-amino aldehyde or ketone (or the acetals or ketals), or an a-amino-)6-ketoester with the salt of a cyanic or thiocyanic acid. Usually the aminocarbonyl hydrochloride is warmed in aqueous solution with one equivalent of sodium or potassium cyanate or thiocyanate. An alkyl or aryl isocyanate or isothiocyanate will give an A-substituted imidazole product (2), as will a substituted aminocarbonyl compound (Scheme 4.1.1) [2-4]. 

The reaction of ethyl 2-(l,2,3,4-tetrahydroisoquinolin-l-yl)acetate hydrochloride with potassium cyanate in boiling water gave 2,3,4,6,7,116-hexahydro-1 //-pyrimido[6,1 -a]isoquinoline-2,4-dione (69IJC684). 3,4,6,7-Tetrahydro-27/-pyrimido[6,l-fl]isoquinoline-2,4-dione and its 2-thioxo derivative were prepared in the reactions of l-methyl-3,4-dihydroisoquinoline with benzoyl isocyanate and ethoxycarbonyl isothiocyanate, respectively, in the presence of NEts (75CB1541). 

A number of compounds contain the K+ ion, and in many cases have the same uses as the corresponding sodium compounds. Examples in which K+ is found include potassium chloride, bromide, iodide, cyanate, nitrate, sulfate, acetate, carbonate, chlorate, chromate, dichromate, ferricyanide, cyanide, hydroxide, perchlorate, permanganate, and persulfate. In household and kitchen products, potassium chloride (KCl) substitutes for NaCl for people with sensitivity to the Na+ in ordinary table salt. As a replacement for sodium chloride, potassium chloride may be recommended to reduce high blood pressure... 

Construction of the simplest fused heterocyclic system that shows some anabolic activity starts by epoxidation of the olefin at C2 in 23-1 with peracetic acid buffered with sodium acetate (23-2) (Scheme 5.23). Reaction of this intermediate with potassium thiocyanate and phosphoric acid, essentially thiocyanic acid, leads to diaxial opening of the oxirane to form the 3a-hydroxy-2/8-cyanate 23-3. Treatment of the product with base leads to formation of the /3-thioepoxide 23-5. Formation of that product can be rationalized by assuming that the first step involves removal by base of a proton on the hydroxyl group. That alkoxide then proceeds to add to the cyano group at C2 to form a transient five-membered ring as in... 

Potassium Cyanate Molecular Sieves Methanol Acetyl Chloride Palladium(ll) Acetate... 

Sodium and potassium cyanates, provided that attention is paid to their short shelf life (Section VII, A,6), offer an attractive alternative to fusion with urea for preparing annelated pyrimidine-2,4-diones. In the Organic Syntheses preparation of quinazoline-2,4-dione, anthranilic acid and potassium cyanate in cold dilute acetic acid were converted (in 20 min) to 2-ureidobenzoic acid, which cold aqueous sodium hydroxide cyclized to the quinazolinedione in excellent overall yield.312 Alternatively, the ring of a ureidobenzoic acid may be closed with hot, dilute hydrochloric acid.257 Ring closure of similar ureides in the pyridine series has required heating at 210°-240°C, often for as long as 3 hr.249,267 An even more Jt-deficient example, 2-aminopyrazine-3-carboxylic acid, did not react with sodium cyanate in dilute acid or with boiling urethane.127... 

Potassium cyanate and methyl 3-methoxyanthranilate, left in cold, acidified aqueous solution overnight, deposited methyl 2-ureido-3-methoxy-benzoate, which, when boiled with water, cyclized to 8-methoxyquinazo-line-2,4-dione methyl 5-chloroanthranilate behaved similarly (no yields stated).257 2-Amino-3-ethoxycarbonyl-JV-methylpyridinium iodide, refluxed for 24 hr with potassium cyanate in dilute acetic acid, was converted in good yield to 8-methylpyrido[2,3-rf]pyrimidine (183).344... 

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