Pyridines phosphorus chlorides

Phosphorus trichloride, Aluminum chloride. Methyl chloride, Methylene chloride, Hydrochloric acid, Isopropyl alcohol, Toluene, Pyridine, Calcium chloride Sodium cyanide, Carbon tetrachloride, Ethyl alcohol,... 

Among the procedures tried were thionyl chloride and pyridine, phosphorus pentachlo-ride, triphenyiphosphine dibromide in N, N-dimethylformamide, triphenylphosphine and carbon tetrachloride, tris(dimethylamino)phosphine and bromine, o-phenylenephosphoro-chloridite and bromine, tris(dimethylamino)phosphine and carbon tetrachloride, and tri-n-octylphosphine and carbon tetrachloride. 

Dehydration Alumina (see also Dihydropyrane, preparation). Boric acid. Boron triSuoride. N-Bromoacetamide-Pyridine-SOj. Dicyclohexylcarbodiimide. Diketene. Dimethylform-amide-Thionyl chloride. Dimethyl sulfoxide. Ethylene chlorophosphite. Florisil. Girard s reagent. Hydrobromic acid. Iodine. Mesyl chloride-Sulfur dioxide. Methyl chlorosulfite. Methylketene diethylacetal. Naphthalene-d-sulfonic acid. Oxalic acid. Phenyl isocyanate. Phosgene. Phosphorus pentoxide. Phosphoryl chloride. Phthalic anhydride. Potassium bisulfate. Pyridine. Thionyi chloride. Thoria. p-Toluenesulfonic acid. p-Toluenesulfonyl chloride. Triphenylphosphine dibromide. 

Dehydration Alumina. Alumina-Pyridine-Diluent (sand). Dicyclohexylcarbodiimide. N,N-Diethyl-l-propynylamine. Dimethyl sulfoxide. Diphenylcarbodiimide. Iodine. Methoxya-cetylene. Oxalic acid. Phenylcyanate. Phosphorus pentoxide-t-Amine. Phosphoryl chloride-Phosphoric acid-Phosphorus pentoxide. Phosphoryl chloride-Pyridine. Thionyl chloride. 

About a decade ago 6-APA and 7-ADCA were mainly produced by chemical deacylation of penicillin G, penicillin V or phenylacetyl 7-ADCA, the last of which was derived from chemical ring expansion of oxidized penicillin G. As a result of the fact that these processes were rather complex and employed hazardous reagents, for example pyridine, phosphorus pentachloride, nitrosyl chloride and dichlorome-thane, alternative processes have been developed. Penicillin amidases (E. C. 3.5.1.11) catalyze the hydrolysis of the linear amide bond in penicillin molecules producing both the P-lactam nucleus, 6-APA and the corresponding side chain without affecting the P-lactam amide bond in the four-membered ring. Based on their substrate specificity the penicillin amidases are grouped into three classes[591 ... 

Optically active phosphorus(iii) acid esters PhR P (OR ) have recently been prepared for the first time by the reaction of a chiral phosphorus chloride and an alcohol or thiol in the presence of an optically active amine, in this case (-)-NN-dimethyl-(l-phenylethyl)amine. (See also Refs. 449 and 450). A kinetic investigation shows that phosphorous acid and chloral react to give 2,2,2-trichloro-l-hydroxyethyl phosphonate at a much lower rate than the corresponding reaction with dimethyl hydrogen phosphite. Phosphorus trichloride and dialkyl phosphites (R0)2P(0)H have been shown to react at low temperature in the presence of pyridine, producing tris(dialkoxyphosphoryl)phosphines [(RO)2P(0)]3P. ... 

HIDROXILAMINA (Spanish) (7803-49-8) A powerful reducing agent. Aqueous solution is a base. Contact with water or steam causes decomposition to ammonium hydroxide, nitrogen, and hydrogen. Contaminants and/or elevated temperatures above (reported at 158°F/70°C and 265°F/129°C) can cause explosive decomposition. Moisture in air or carbon dioxide may cause decomposition. Violent reaction with oxidizers, strong acids, copper(II) sulfate, chromium trioxide, potassium dichromate, phosphorus chlorides, metals calcium, sodium, zinc. Incompatible with carbonyls, pyridine. Forms heat-sensitive explosive mixtures with calcium, zinc powder, and possibly other finely divided metals. Aqueous solution incompatible with organic anhydrides, acrylates, alcohols, aldehydes, alkylene oxides, substituted allyls, carbonyls, cellulose nitrate, cresols, caprolactam solution, epichlorohydrin, ethylene dichloride, glycols, isocyanates, ketones, nitrates, phenols, pyridine, vinyl acetate. Attacks aluminum, copper, tin, and zinc. 

PHOSPHORUS CHLORIDE (10025-87-3) Fumes in moist air. Contact with water, steam, or alcohols produces hydrochloric acid, phosphoric acid, and phosphine gas, which is pyrophoric, with possible ignition or explosion (may be a delayed reaction). Contact with air produces corrosive fumes. Violent reaction with carbon disulfide, 2,6-dimethylpyridine-iV-oxide, dimethyl sulfoxide, ferrocene l,l -dicarboxylic acid, pyridine, zinc powder. Reacts, possibly violently, with acids, alkali metals, alkalis, combustible materials, dimethyl for-mamide, organic matter, zinc powder. Incompatible with acetic anhydride, yV,V-dimethyl formamide, 2,5-dimethylpyrrole, sodium. Rapid corrosion of steel and most metals, except lead, occurs in the presence of moisture. 

Pyridine phosphorus oxide chloride o-Chloro-N-heterocyclics... 

Many alcohols undergo dehydration at 0°C when treated with phosphorus oxychloride (POCI3) in the basic solvent pyridine. (Phosphorus oxychloride is the acid chloride of phosphoric acid, with chlorine atoms in place of the hydroxyl groups of phosphoric acid.)... 

Phosphorus pentachloride has often been used to remove amido side chains in the cephalosporin and penicillin series (Fechtig et al., 1968 Chauvette et al., 1971, 1972). This reaction proceeds through imino chlorides which are subsequently hydrolyzed to amines. Researchers at Lilly laboratories found (Lunn et al., 1974) that reaction of cephamycin diesters 428 and 429 with phosphorus pentachloride in pyridine-methylene chloride for 1 hr at 25°C also formed imidoyl chlorides (430). To exploit the interesting observation that alcohols are capable of converting imidoyl chlorides directly to amines, 430 was treated with methanol and subsequently with phenoxyacetyl chloride (pyridine). 7-Amido-7-methoxy-cephalosporins were isolated in 40% yield as a mixture of C-7 epimers (433 and 434). These materials can be distinguished from each other by the H-NMR signal of the C-6 proton. The ratio of 7a- to 7p-methoxy... 

Trifluoroacetic anhydride is a most effective catalyst for the direct esterification of carboxylic acids by primary, secondary, and tertiary alcohols. Esterification proceeds under mild conditions via a mixed anhydride but is not successful with carboxylic acids of very low pKa and hydroxy acids when the reagent promotes lactonisation or polymerization [23, 24]. Dibasic acids may be esterified if they do not readily form cyclic anhydrides. Reagents such as trifluoromethane sulphonic anhydride [25], acetyl chloride [26], pyridine/p-toluene-sulphonyl chloride [27], sulphury chloride [28], thionyl chloride [29], and pyridine/phosphorus oxychloride [30] probably act in a similar way to trifluoracetic anhydride as reagents for direct esterification. 

Pyridine phosphorus oxide chloride 2-Ghloropyridines from 2-pyridones s. U, 608... 

Pyridine phosphorus oxide chloride Ring contraction of l,3-S,S-heterocyclics with formation of chlorides from alcohols Alcohols from chlorides... 

Phosphorus trichloride reacts readily with three equivalents of an alcohol e.g, ethanol, in the presence of a tertiary amine such as pyridine, dimethyl-aniline, or diethylaniline, to form triethyl phosphite and hydrogen chloride, the latter being immediately neutralised by the tertiary amine. 

A thioamide of isonicotinic acid has also shown tuberculostatic activity in the clinic. The additional substitution on the pyridine ring precludes its preparation from simple starting materials. Reaction of ethyl methyl ketone with ethyl oxalate leads to the ester-diketone, 12 (shown as its enol). Condensation of this with cyanoacetamide gives the substituted pyridone, 13, which contains both the ethyl and carboxyl groups in the desired position. The nitrile group is then excised by means of decarboxylative hydrolysis. Treatment of the pyridone (14) with phosphorus oxychloride converts that compound (after exposure to ethanol to take the acid chloride to the ester) to the chloro-pyridine, 15. The halogen is then removed by catalytic reduction (16). The ester at the 4 position is converted to the desired functionality by successive conversion to the amide (17), dehydration to the nitrile (18), and finally addition of hydrogen sulfide. There is thus obtained ethionamide (19)... 

Nitric acid works Paraffin oil (kerosene) works Petrochemical works Petroleum works Phosphorus works Picric acid works Producer gas works Pyridine works Selenium works Smelting works Sulfate of ammonia works and chloride of ammonia works... 

Methoxy-5//-pyrido[2,3-c]azepin-9(8//)-one (4) on chlorodehydroxylation with phosphoryl chloride in A,A, -dimethylaniline yields a mixture (20 %) of the chlorc)-6-methoxypyrido[2,3-c -azepines5and6.192 An unseparablemixture (3 7) of 5H- and 7ff-pyrido[2,3-c]azcpine-9-thione 7 and 8 is obtained on treating the pyridoazepinone 4 with phosphorus pentasulfide in warm pyridine. 

Trinitrochlorobenzene (piciyl chloride) in pyridine-A -mcthylpyrrolidi-none (NMP) solutions were later used for the preparation of polyesters from dicarboxylic acids and diphenols or aliphatic diols,309 but better results have been obtained with sulfonyl chlorides and phosphorus compounds. 

Carbon-phosphorus double bonds are also formed in addition reactions of tris(trimethylsilyl)phosphine 1692 (which can be readily prepared from white phosphorus, sodium, and TCS 14 [13a,b,c]) to give oxazohum fluorides 1691 which then give the azaphospholes 1694, via 1693 [3, 14]. On addition of 1692 to 1695, the diazaphosphole 1696 [3, 15] is prepared, whereas l,3-azaphospholo[l,2a]pyridines 1698 [16] are formed from 1692 and 1697, and 1,3-thiaphospholes 1700 are formed from the dithiohum fluorides 1699 [17]. l,3-Benzodiphospholyl anions 1703 are generated by reaction of acid chlorides with the dihthium salts 1701, via 1702 [18] (Scheme 11.3). 

The factors affecting the preparation of the cyclic chlorophosphazenes from phosphorus pentachloride and ammonium chloride continue to receive attention. For example, the yields and reaction times for the preparation of the series, (NPCla) ( — 3—7), varied with the fineness of the ammonium chloride, the nature and volume of the solvent, and added catalysts such as phosphoryl chloride. A procedure, giving due consideration to these factors, was described for the preparation of N3P3CI6 in good yield (88% of cyclic products) and in a relatively short time (2J h). The cyclic chlorophosphazenes can be obtained in even shorter times ca. 10 min) by addition of four moles of pyridine to remove the hydrogen chloride formed ... 

In a 500-cc. three-necked flask, fitted with a mechanical stirrer, thermometer, separatory funnel, and calcium chloride tube, are placed 96 g. (56.5 cc., 0.36 mole) of redistilled phosphorus tribromide (b.p. 174-175°/740 mm.) and 50 cc. of dry benzene. From the separatory funnel, 15 g. of dry pyridine is added with stirring over a period of fifteen minutes. The flask is then surrounded by an ice-salt mixture, and the contents are cooled to — 5°. A mixture of 102 g. (1 mole) of redistilled tetrahydrofur-furyl alcohol (b.p. 79-80°/20 mm.) and 5 g. of dry pyridine (total pyridine, 20 g., 0.25 mole) is added slowly from the dropping funnel with stirring over a period of four hours. During this time the internal temperature is kept at —5° to —3°. Stirring is continued for one hour longer, and the cooling bath is then allowed to warm up to room temperature. 

Phosphorus, white Phosphoryl chloride Air, oxidants of all types, halogens, metals Carbon disulfide, AtA -dimethylformamide, 2,5-dimethylpyrrole, 2,6-dimethyl-pyridine 1-oxide, dimethylsulfoxide, water, zinc... 

B. l-Eihyl-3-(3-dinuthylamino)propylcarbodiimide hydrochloride. A suspension of 34.6 g. (0.300 mole) of pyridine hydrochloride (Note 7) in 280 ml. of methylene chloride is prepared in a 1-1. Erlenmeyer flask. To this is slowly added 46.5 g. (0.300 mole) of l-ethyl-3-(3-dimethylamino)propylcarbodiimide. The resulting solution is diluted with anhydrous ether (Note 8) and stored at 0-5° for 16-20 hours. The crystalline product is collected by filtration in a dry atmosphere (Note 9), washed with a little anhydrous ether, and dried under reduced pressure over phosphorus pentoxide. The yield is 50.5-55.5 g. (88-96.5%), m.p. 104-109° (Notes 10 and 11). This material is sufficiently pure for most purposes. 

The 2-chloroethyl group, which is often an effective toxo-phore, was then attached to phosphorus through oxygen. No reaction appeared to take place between ethylene chlorohydrin and diethyl phosphorochloridate in the absence of a tertiary base. In the presence of pyridine, however, which removed the hydrogen chloride formed, a smooth reaction took place at 0° with the formation of diethyl 2-chloroethyl phosphate,... 

Triaryl esters can be prepared by a variety of methods. For example, by allowing 3 mol. of the phenol to react with 1 mol. of phosphorus oxychloride for several hours. Organic bases such as aniline, dimethylaniline and pyridine have been used to neutralize the hydrogen chloride formed in the reaction.3 Alternatively, the phenols may be converted into the sodium phenoxides4 and then allowed to react with phosphorus oxychloride. 

Triphenyl phosphite can be prepared by the gradual addition of phosphorus trichloride to a mixture of phenol and pyridine.6 It is claimed that magnesium chloride can be used in place of pyridine.7... 

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