Phosphorus oxide phosgene

Acidic reagents seem to offer milder conditions. Dehydration reactions forming cyanides can be performed with phosgene [1049-1052], diphosgene [1053-1055], triphosgene [1056], phenyl chloroformate [1057], oxalyl chloride [1058, 1059], tri-chloroacetyl chloride [1060-1062], acetic anhydride [1063-1074], TFAA [1075-1082], phosphorus oxides [1083-1088], phosphorus oxychloride [1089-1098], phosphorus pentachloride [1099], triphenylphosphine/haloalkanes [1100-1103], thionyl chloride [1104-1118], p-tosyl chloride [1119-1124], triflic anhydride [1125-1127], chlorosulfonyl isocyanate [1128], the Burgess reagent [1129], phenyl chloro-thionoformate [1130], cyanuric chloride [1131-1134], carbodiimides [1135, 1136], CDC [1137], PyBOP [1138], AlCU/Nal [1139], and acetonitrile/aldehyde [1140], and by pyrolysis [1141]. 

Liquid aliphatic halides are obtained alcohol-free by distillation from phosphorus pentoxide. They are stored in dark bottles to prevent oxidation and, in some cases, the formation of phosgene. 

Guanidines have been prepared by the reaction between an amine, or an amine salt, and a host of other reagents, such as a thiourea in the presence of lead or mercuric oxide [83, 157, 158], carbodi-imides [140, 174, 175],calcium cyanamide [176, 177], isonitrile dichlorides [178—180], chloroformamidines [181], dialkyl imidocarbonates [182], orthocarbonate esters [183], trichloro-methanesulphenyl chloride [184], and nitro- or nitroso-guanidines [185-188]. Substituted ureas can furnish guanidines, either by treatment with amines and phosphorus oxychloride [189], or by reaction with phenylisocyanate [190] or phosgene [191]. 

Ketone Method. In the ketone method, die central carbon atom is derived from phosgene. A diarylketone is prepared from phosgene and a tertiary arylamine and then condenses with another mole of a tertiary arylamine (same or different) in the presence of phosphorus oxychloride or zinc chloride. The dye is produced directly without an oxidation step. Thus, ethyl violet CT Basic Violet 4, is prepared from 4.4 -bis(diethy]amino)benzophenone with diethylaniline in the presence of phosphorus oxychloride. This reaction is very useful for the preparation of unsymmetrical dyes. 

Phosphorus oxychloride reacts with ethylene oxide in the presence of aluminum chloride to give tris-2-chloroethyl phosphate, a valuable plasticizer (75). Phosgene reacts with ethylene oxide and other alkylene oxides to form esters of chlorocarbonic acid (76) (see Carbonic and carbonochloridic esters). 

There are two general routes to arylsulfonyl chlorides. The first involves the conversion of an already sulfur-substituted aromatic compound to the sulfonyl chloride. Thus arylsulfonic acids or their alkali metal salts yield sulfonyl chlorides by treatment with a variety of chlorinating agents such as phosphorus pentachloride, thionyl chloride, phosgene, and chlorosulfonic acid. Alternatively, substituted thiophenols or aryl disulfides can be oxidized by chlorine-water to the sulfonyl chloride.6... 

Qiloroacetyl cliloride is manufactured by reaction of cliloroacetic acid with chlorinating agents such as phosphorus oxychloride, phosphorus trichloride, sulfuryl cliloride, or phosgene (42—44). Various catalysts have been used to promote the reaction. Qiloroacetyl cliloride is also produced by chlorination of acetyl cliloride (45—47), the oxidation of 1,1-dichloroethene (48,49), and the addition of chlorine to ketene (50,51). Dicliloroacetyl and trichloroacetyl cliloride are produced by oxidation of tricliloroethylene or tetrachloroethylene, respectively. 

Note Carbon-, sulfur-, nitrogen-, and phosphorus-containing solvents will evolve oxides of their constituent elements, including CO, on combustion, and these gases are toxic and probably irritants if a fire involving such materials is encountered. Some chlorinated solvents can form phosgene (carbonyl chloride) in fires. 

The maiin domain of oxidation with dimethyl sulfoxide is the conver-sionofprimary alcoholsinto aldehydes andofsecondaryalcoholsintoketones. These reactions are accomplished under very mild conditions, sometimes at temperatures well below 0 °C. The reactions require the presence of acid catalysts such as acetic anhydride [713, 1008, 1009], trifluoroacetic acid [1010], trifluoroacetic anhydride [1011, 1012, 1013], trifluorometh-anesulfonic acid [1014], phosphoric acid [1015, 1016], phosphorus pentox-ide [1006, 1017], hydrobromic acid [1001], sulfur trioxide [1018], chlorine [1019, 1020], A -bromosuccinimide [997], carbonyl chloride (phosgene) [1021], and oxalyl chloride (the Swem oxidation) [1022, 1023, 1024], Dimethyl sulfoxide also converts sufficiently reactive halogen derivatives. into aldehydes or ketones [998, 999] and epoxides to a-hydroxy ketones at -78 °C [1014]. 

Although of little global significance on Earth, this reaction is of tremendous importance on Venus. Oxides of phosphorus have been detected, by the Soviet Vega probes, in the Venusian lower cloud level, and are believed to be products of hypergenesis and, possibly, volcanic activity [50a]. Phosgene is icnown to be formed in the Venusian clouds by... 

Gent-dichlorides can be obtained from ketones that are not capable of conversion into an enol form by using phosgene in the presence of an organic phosphorus compound [316], For example, PhjC=0 was converted into PhjCClj in the presence of one of a wide variety of phosphine or phosphine oxide catalysts between 100 and 190 C. Further, PhC(0)C(0)Ph, when treated with COClj in the presence of PPhjO at 130-140 C, resulted in the conversion of one of the CO groups into a CClj moiety. PhC(0)-4-C 4C(0)Ph reacted in the... 

The relatively stable carbon-phosphorus bond is resistant to cleavage by phosgene in a way that is similar to a carbon-carbon bond in a hydrocarbon chain. The phosphorus atom, in its formal oxidation state of +3 in an organic compound, however, may react by virtue of its unshared electron pair. 

New Jersey adopted a Toxic Catastrophe Prevention Act in 1986, which requires risk assessment by companies.167 The Kanawha Valley Hazardous Assessment Project in West Virginia developed worst-case scenarios for 12 chemical plants in the area.168 The chemicals studied included acrylonitrile, vinylidene chloride, butyl isocyanate, methylene chloride, chlorine, phosphorus trichloride, hydrogen sulfide, methyl isocyanate, phosgene, ethylene oxide, sulfur trioxide, and others... 

The 5-(acylhydrazono)-5,6-dihydro-4//-l, 3,4-oxadiazine (167) on treatment with phosgene yields the l,3,4-oxadiazolyl-6//-l,3,4-oxadiazine (168), while with phthaloyl chloride, under similar conditions, the spiro compound (169) is produced. However, with thionyl chloride and with phosphorus oxychloride, ring formation involving N-3 is observed to yield the thiatriazolo[5,4-d][l,3,4]-oxadiazine 3-oxide (170) and the l,2,4-triazolo[4,5-. 

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