Dimethylformamide-Sodium acetate

Type 4A sieves. A crystalline sodium aluminosilicate with a pore size of about 4 Angstroms, so that, besides water, ethane molecules (but not butane) can be adsorbed. This type of molecular sieves is suitable for drying chloroform, dichloromethane, diethyl ether, dimethylformamide, ethyl acetate, cyclohexane, benzene, toluene, xylene, pyridine and diisopropyl ether. It is also useful for low pressure air drying. The material is supplied as beads, pellets or powder. 

Reaction of 1,3-dicarbonyl compounds with IVJV-dimethylformamide dimethyl acetal followed by malonamide in the presence of sodium hydride gives 5,6-disubstituted 1,2-dihydro-2-oxopyridine-3-carboxamides, whereas reaction of the intermediate enamines with cyanothioacetamide or cyanoacetamide in the presence of piperidine provides 2-thioxopyridine-3-carboxamides and 4,5-disubstituted l,2-dihydro-2-oxopyridine-3-carboxamides, respectively <95S923>. P-Enaminonitriles 14 react with p-ketoesters and alkyl malonates, in the presence of stoichiometric amounts of tin(IV) chloride, to afford 4-aminopyiidines 15 and 4-amino-2-pyridones 16 <95T(51)12277>. 

Triazinethiones have been used frequently for the syntheses of triazino-triazines in the literature. Reaction of 6-methyl-5-[substituted styryl]-2/7-[l,2,4]triazine-3-thiones 39 with thiourea or acetylthiourea in dimethylformamide (DMF) led to the formation of N,N -disubstituted thioureas 40. Heating the compound 40b with glacial acetic acid and fused sodium acetate under reflux led to the formation of the compounds 4,7-dimethyl-8-[2-ethenylfuran]-2-thioxo-l,3,5-triazino[5,6- ][l,2,4]triazine 22 (Scheme 6) <2003PS279>. 

The coupling of Naphtol AS or its phenyl-substituted derivatives with diazonium salts from variously substituted anilines in aqueous alkaline solution (section 4-11) gave incomplete reactions and impure products in some instances, probably because these coupling components have inadequate solubility in aqueous media. Pure dyes in ca. 90% yields were obtained by reaction in dimethylformamide in the presence of sodium acetate. Metallisation of these o,o -dihydroxyazo ligands with sodium chromium salicylate or a cobalt(II) salt gave metal-complex dyes in 80-100% yields [22]. Specific structural isomers of these complexes were identified by i.r., n.m.r., Raman and UV/visible spectroscopy [23]. 

Reacting this with sodium methoxide leads to the formation of an epoxide— 9-(2, 3 -anhydro- 8-luxofuranosyl)adenine (36.1.9). Finally, heating this epoxide with sodium acetate or benzoate opens the epoxide ring in the dimethylformamide-water system to make the corresponding dihydroxy derivative, vidarabine [12,13]. 

Aluminum foil, Iodine powder. Carbon disulfide, 1,4,6,9-Tetrabromodiamantane, Sodium bisulfite. Hydrochloric acid. Methanol, Acetonitrile, Acetone, Sodium hydroxide. Magnesium sulfate. Potassium permanganate. Toluene Methylene chloride, 2-Bromomethanol, Trioxane, Aluminum chloride. Magnesium sulfate, Nitroform, Acetone, Sodium bicarbonate. Hexane, Silver nitrate. Acetonitrile 1,2-Dichloroethane, HexamethyldisUane, Iodine, Cyclohexane, 1,3-Dioxolane, Nitroform, Methylene chloride, Dimethylformamide, Sodium sulfate. Hydrochloric acid. Magnesium sulfate. Nitric acid. Sulfuric acid Sulfuryl chloride. Acetic anhydride. Nitric acid. Sodium bicarbonate. Sodium sulfate Nitric acid. Sulfuric acid, Malonamide Nitric acid. Sulfuric acid, Cyanoacetic acid Sulfuric acid, Acetasalicyclic acid. Potassium nitrate Nitroform, Diethyl ether, 1-Bromo-l-nitroethane, Sodium sulfuate... 

Similar treatment of the C-heteroarylhydrazonoyl bromide 28c with sodium acetate in glacial acetic acid gave the hydrazide 305 in 85% yield. Heating 305 in dimethylformamide in the presence of bases afforded 4-acetyl-7-bromo-2-(5-bromo-2-thienyl)-4//-l, 3,4-benzoxadiazine 306 in 6% yield [72JCS(P1)2915]. 

Diallyl sulfate, 2437 f 1,1-Dichloroethylene, 0691 l,4-Dicyano-2-butene, 2304 Diisocyanatomethane, Dimethylformamide, 1076 f Diketene, Acids, or Bases, or Sodium acetate, 1437... 

Primary trialkylboranes were directly converted into carboxylic acids by the oxidation with pyridinium dichromate in dimethylformamide, sodium dichromate in aqueous sulfuric acid, or chromium trioxide in 90% aqueous acetic acid (Equation (106)).509... 

A reactor was charged with N,N-dimethylformamide dimethyl acetal (700 mmol) and pyruvaldehyde dimethyl acetal (700 mmol), heated to 110°C 4 hours, cooled to 85 °C, and thiourea (636.4 mmol) and sodium methoxide (700 mmol) dissolved in 160 ml methyl alcohol added. Thereafter, the mixture stirred 4 hours. The mixture was cooled to 65 °C and 1-bromopropane (700mmol) added over 15 minutes. After 1 hour, 100ml EtOAc was added and the mixture heated to 95 °C. The solvents were distilled off, 120 ml water added, the mixture stirred 10 minutes at 50°C, cooled, concentrated, and the product isolated as a yellow oil. NMR data supplied. 

The isothiocyanates are transformed into thiocarbamates by reaction with alcohols or into the acetamides by reaction with acetic acid or anhydride and sodium acetate. These transformations have also been applied to the preparation of unsaturated aminosugars73,74. Thus, suprafa-cial rearrangement of ethyl 2.3,4-trideoxy-6-0-methanesulfonyl-4-thiocyan ato-a-D-t/ireo-hex-2-enopyranoside to the 2-isothiocyanatc occurs in refluxing toluene (1 h), whereas the erythro-epimer needs to be heated in dimethylformamide for 6 hours73. This difference in reactivity might be due to an unfavorable anomeric effect and C-6 in an axial orientation in the transition state of the errr/iro-epimer, respectively. 

O-p-tolylsulfonyl-a-D-xylopyranoside (197), obtainable therefrom, was transformed by sodium acetate in N,N-dimethylformamide into methyl 4-acetamido-4-deoxy-a-D-ribopyranoside (198a) by inversion at C-3. The )S-D anomer of 198 is obtainable from methyl 2,3-0-isopropylidene-4-O-p-tolylsulfonyl-a-L-lyxopyranoside by inversion at C-4 to the corresponding 4-azido-4-deoxy-D-Wbo compound. ... 

OLEFINS N,N-Dimethylformamide dimethyl acetal. Iron pentacarbonyl. 0-4-Methylphenyl chlorothioformate. Naphthalene-Sodium. Potassium hexachloro-tungstate. Sodium methylsulflnylmetbyl-ide. Sodium sulfide. p-Tolucnesulfonyl-hydrazine. Trimethyl phosphite. Ttiphen-ylphosphine. 

Abbreviations conform to Tarr s nomenclature F, formic acid A, acetic acid fA, trifluoroacetic acid KNm, dimethylformamide mSO, methylsulfoxide MOH, methanol EOH, ethanol MCN, acetonitrile M5KN, N-methyl-pyrrolidone 6N, pyridine N, ammonia ENm, dimethylethylamine M6N, N-methylpiperidine M6NO, N-methylmorpholine E6NO, N-ethylmorpholine ENip, diisopropylethylamine eN, triethylamine fmK, hexafluoroacetone (hydrate) cit, citric acid W, water NaA, sodium acetate eN+, tetraethylammonium MNT, methylthiocarbamyl NT, phenylthiocarbamyl MNGS, methylisothiocyanate ONCS, phenylisothiocyanate NPN-TNdab, N-aminopropyl-N -p-dimethylaminoazobenzene thiourea. 

Coates and Shaw have published the complete details of their successful synthesis of calerene (476). After much experimentation these workers found that reaction of the monopyrrolidine enamine of 2-methylcyclohexane-l,3-dione (477) with pent-3-en-2-one in the presence of acetic acid, sodium acetate, and dimethylformamide afforded the two diketones (478) and (479) in the ratio 1 1 in 27 % yield. Monothioketalization of this mixture followed by desulphura-tion and ethoxycarbonylation gave the two j8-keto-esters (480) and (481) which could be separated by column chromatography. N.m.r. spectra indicated that the former existed predominantly as the keto-tautomer while the latter was mainly in the enol form. Treatment of (480) with methyl-lithium followed by dehydration gave the isopropylidene ketone (482). Reaction of (482) with... 

Amino-5-chloromethyl-3-cyanopyrazine on treatment with potassium acetate in propan-2-ol at 80-90° gave 5-acetoxymethyl-2-amino-3-cyanopyrazine(542),and 2-amino-6-chIoro-5-chloromethyl-3-cyanopyrazine with anhydrous sodium acetate in dimethylformamide gave 2-acetoxymethyl-5-amino-3-chloro-6-cyanopyrazine (874). 

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