Sodium formamidinate

Continuous polymerization in a staged series of reactors is a variation of this process (82). In one example, a mixture of chloroprene, 2,3-dichloro-l,3-butadiene, dodecyl mercaptan, and phenothiazine (15 ppm) is fed to the first of a cascade of 7 reactors together with a water solution containing disproportionated potassium abietate, potassium hydroxide, and formamidine sulfinic acid catalyst. Residence time in each reactor is 25 min at 45°C for a total conversion of 66%. Potassium ion is used in place of sodium to minimize coagulum formation. In other examples, it was judged best to feed catalyst to each reactor in the cascade (83). 

The primary synthesis of alkoxypyrimidines is exemplified in the condensation of dimethyl malonate with O-methylurea in methanolic sodium methoxide at room temperature to give the 2-methoxypyrimidine (854) (64M207) in the condensation of diethyl phenoxymalonate with formamidine in ethanolic sodium methoxide to give the 5-phenoxypyrimidine (855) (64ZOB1321) and in the condensation of butyl 2,4-dimethoxyacetoacetate with thiourea to give 5-methoxy-6-methoxymethyl-2-thiouracil (856) (58JA1664). 

In closely related studies, the molecular and crystal structures of lithium, sodium and potassium N,N -di(p-tolyl)formamidinate and N,N -di(2,6-dialkyl-phenyl)formamidinate complexes have been elucidated. These showed the anions to be versatile ligands for alkali metals, exhibiting a wide variety of binding modes. ... 

Vat dyes in general have the disadvantage that reduction to a water-soluble form is necessary before application to cellulosic textiles. Traditionally sodium dithionite in alkaline solution serves as the reducing agent. An alternative sometimes used in vat printing is thiourea dioxide, which is converted into formamidine sulphinate in alkaline solution (section 12.9.1). 

The greater stability of the pyrazine ring to oxidation compared with that of benzene enables pyrazinecarboxylic acids to be prepared by permanganate oxidation of either quinoxalines or phenazines. The pyrazine ring is more stable than the pyrimidine ring to acid and alkaline hydrolysis. Thus, pteridine is converted into 2-amino-3-formylpyrazine on treatment with dilute sulfuric acid and N-(3-formyl-2-pyrazinyl)formamidine oxime on treatment with sodium carbonate and hydroxylamine (Scheme 11).136 Aminopyrazines and... 

Because of this low oxidation-reduction potential, the number of methods available for reducing ferredoxin is limited. Apart from hydrogen gas, ferredoxin may be reduced with organic reductants, such as pyruvate or hypoxanthine in the presence of the appropriate enzymes. Ferredoxin can be reduced nonenzymically with sodium hydrosulfite (dithionite) (Tagawa and Arnon (99) Fry et al. (45)), potassium borohydride (D Eustachio and Hardy (40)), and formamidine sulfinic acid (Shashoua (90)). It can be reduced also by illuminated chloroplasts (Whatley, Tagawa, and Arnon (114)) and, under these conditions, the reduction of ferredoxin is most complete (Bachofen and Arnon (12)). 

Treatment of compound (192) with sodium hydroxide in DMSO gives the pyrimidine (196). It is most likely that this product (1%) is formed via addition of water to the C=N bond adjacent to the benzoyl group (Scheme 12). This affords the formamidine (193) which undergoes benzylic-like rearrangement to the acid (194) which cyclizes (194) - (195). Decarboxylation and N—N bond cleavage in the pyrazole moiety gives the final isolable product (196) <83CPB395i>. 

Formamidine reacts with a-hydroxyketones95 and a-haloketones62 to yield oxazoles and imidazoles. Normally the formamidine is liberated from its hydrochloride by the addition of sodium butoxide in n-butanol. It is interesting to note that in the reaction with a-hydroxyketones, the aliphatic acyloins yielded mainly imidazoles (35-68% yield), whereas the benzoins gave mainly oxazoles (67-80%).95 Unlike formamidine, acetamidine and benzamidine react with both aliphatic acyloins and with benzoins to yield imidazoles exclusively.65 Bredereck65 explains the reactions as follows ... 

When amidines or guanidines cyclize in the presence of a-functionalized carbonyl reagents they form imidazoles with a variety of 1-, 2-, 4- and 5-substituents [1, 2]. Formamldine will react with a-hydroxy- [8] or a-halogenoketones [9], to give mixtures of oxazolcs and imidazoles. Usually, the formamidine is liberated from its hydrochloride by treatment with sodium butoxide in butanol. When the two-carbon synthon is an a-hydroxyketone the aliphatic members mainly form imidazoles (35-70%), while benzoins give oxazoles (67-80%) preferentially [8], The competing pathways are shown in Scheme 4.3.1. 

When 3,4-disubstituted 4-aminoisoxazolin-5(4Af)-ones (9) are hydrogenated, and then subsequently recyclized, high yields of imidazoles (10) are obtained (Scheme 6.1.4). The starting materials can be readily made from isoxazolin-5(4Af)-ones by sequential bromination, reaction with sodium azide and conversion of azide into amino by reaction with hydrobromic acid in acetic acid. The amines are then converted into formamidine or acetamidine derivatives with DMF or dimethylacetamide under reflux in phosphoryl chloride-chloroform. Yields at this stage are 50-93%. Catalytic... 

Heterocycles Acetylacetone. N-Aminophthalimide. Boron trichloride. Dichloro-formoxime. Oicyanodiamide. Dicyclohexylcarbodiimide. Dietboxymethyl acetate. Diethyl oxalate. Diketene. Dimethylformaniide diethylacetal. Diphenyldiazomethene. Ethyl ethoxy-methylenecyanoacetate. Formaldehyde. Formamide. Formamidine acetate. Formic acid. Glyoxal. Hydrazine. Hydrazoic acid. Hydroxylamine. Hydroxylamine-O-sulfonic acid. Methyl vinyl ketone. o-Phenylenediamine. Phenylhydrazine. Phosphorus pentasullide. Piperidine. Folyphosphoric acid. Potassium diazomethanedisulfonate. Sodium ethoxide. Sodium nitrite. Sodium thiocyanate. Tetracyanoethylene. Thiosemicarbozide. Thiourea. Triethyl orthoformate. Tris-formaminomethane. Trityl perchlorate. Urea. Vinyl triphenyl-phosphonium bromide. 

Verpooten GA, Verbist L, Buntinx AP, Entwistle LA, Jones KEI, De Broe ME. The pharmacokinetics of imipenem (thienamycin-formamidin) and the renal dehydropeptidase inhibitor cilastatin sodium in normal subjects and patients with renal failure. Brit J Clin Pharmacol 1984 18 193-193. 

Fluoroheptyl acetate from l-bromo-2-fluoroheptane and sodium acetate, 46,37 Formaldoxime, 46,13 reaction with 2-bromo-4-methylbeL zenediazonium chloride, 46,14 Formamidine, from hydrogen cyanide,... 

Alternatively, the construction of these nucleosides was achieved from the alkoxyamine derivative 520 by conversion to the respective formamidine 519. Transamidination followed by boron-trifluoride-catalyzed cyclization gave the imidazoles 522. Their cyclization was effected using sodium methyl-... 

A proposed mechanism for the condensation of formamidine sulfinic acid with the dicarbonyl equivalent involves attack of the amidine nitrogen atoms on both of the electrophilic centers with loss of water. The imidazole phosphonium salt does not react directly with sodium methoxide but instead generates the reactive methylene imidazole intermediate, which is trapped by MeOH. Reactivation can be promoted in protic solvents to elongate the chain to provide cimetidine. 

Sodium methoxide 4-Aminopyrimidine ring from o-aminonitriles Formamidines from amines... 

Reductive bleaching, with either (sodium) dithionite or FAS (formamidine sulfi-nic acid) as the bleaching agent, for color value correction and brightness increase by color stripping and fiber lightening. 

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