Sodium reaction with chlorine

Dichloropyridazine 1-Oxide produces both isomers with alkoxides. However, the ratio is dependent on the size of the alkoxy group. In the reaction with sodium methoxide 80% of 6-chloro-3-methoxypyridazine 1-oxide and 7.5% of 3-chloro-6-methoxypyridazine 1-oxide are formed. Similar results are also obtained with sodium ethoxide, while sodium propoxide affords only 6-chloro-3-propoxypyridazine 1-oxide. Amines react similarly, while only chlorine at the 3-position can be substituted with an azido group to give 3-azido-6-chloropyridazine 1-oxide. 

The dechlorination of the C-3 and C-5 position of the pyrazinone system was described to be fast under microwave irradiation [29]. Contrary to the reported de-chlorination [26] via palladium-catalyzed reaction with sodium formate 100 °C for 2-4 h and at the C-5 position in 2-3 days, a dramatic rate enhancement was observed under microwave irradiation (Scheme 12). The mono-reduction at C-3 was performed at 190 °C in DMF in merely 5 min, and the reduction of C-5, starting from the mono-reduction product, was performed in n-butanol in 55 min to afford the fois-reduction product in good overall yield. 

When chlorine reacted with sodium diethyl dithiophosphate in the presence of an organic solvent, the desired compound was obtained in good yield. The reaction of phosphorus pentachloride on the sodium salt resulted in the same product. Thiophos-phoryl chloride is a probable by-product of this reaction. It was later found that diethyl dithiophosphoric acid could be chlorinated in an organic solvent without the intermediate preparation of the sodium salt. 

Of great importance was the discovery by Johnson et al. (185) of the stereospecific synthesis of optically active sulfonimidoyl chlorides, which are key substrates for making new types of sulfonimidoyl compounds. The method involves chlorination of readily available chiral sulfinamides with chlorine or A/-chlorobenzotriazole. Scheme 12 summarizes the synthesis of (-)-(/ )-A/-methylphenylsulfonimidoyl chloride 163 from (+HS>N-methyl benzenesulfinamide 164 and its reactions with sodium phenoxide and dimethylamine. 

Diclofenac Diclofenac, 2-[(2,6-dichlorophenyl)-amino]-phenylacetic acid (3.2.42), is synthesized from 2-chIorobenzoic acid and 2,6-dichloroaniline. The reaction of these in the presence of sodium hydroxide and copper gives iV-(2,6-dichlorophenyl)anthranyIic acid (3.2.38), the carboxylic group of which undergoes reduction by lithium aluminum hydride. The resulting 2-[(2,6-dicholorphenyl)-amino]-benzyl alcohol (3.2.39) undergoes further chlorination by thionyl chloride into 2-[(2,6-dichlorophenyl)-amino]-ben-zylchloride (3.2.40) and further, upon reaction with sodium cyanide converts into... 

Various organic dihalides are employed in a reaction with sodium polysulfide to produce organic polysulfides (Thiokols). Ethylene dichloride, from the direct chlorination of ethylene, dichloroethyl formal, and /3,0 -dichlorodiethyl ether are the principal dihalides that have been employed in the process (44). These elastomeric polymers have been commercially available for a number of years, and many applications have been developed for them. They have excellent oil resistance and one of their principal uses has been in hose and tank linings in which that property is required. 

If the ketone has a methyl group containing chlorine, the reaction can take the other possible pathway, and the chlorofluoromcthane can hydrolyze, because of the variable stability of the chlorine-substituted methyl carbanions in alkali. l-Chloroheptafluorobutan-2-one (8), 1,1-di-chlorohexafluorobutan-2-one (9), and l,l,l-trichloropentafluorobutan-2-one (10) on reaction with sodium hydroxide give sodium pentafluoropropanoate (11).174... 

RR SiCr, Na+ (equation (7)). The propagation step (equation (8)), which is rapid but nevertheless rate determining, is the reaction of anion-terminated chains with dichlorosi-lane to add one silicon unit and produce a chlorine-ended chain. The latter is thought to be reduced rapidly to the anionic form by reaction with sodium. The polysilane chains will alternately be terminated with silyl anions or Si-Cl. This is consistent with evidence from chemical derivatization that both may be present in the products of the reaction. ... 

The naphthalimide ring system has the drawback of low effectiveness, which is mainly attributable to the low molar extinction coefficient. The industrial synthesis of alkoxynaphthalimides begins with acenaphthene. Chlorination and subsequent oxidation with dichromate give the corresponding naphthalic acids [116], which are converted to the anhydrides on drying. Mild reaction with methyla-mine, followed by reaction with sodium methoxide or sodium ethoxide, gives, e.g., 64 or 65. 

Chemical reactions Formation of trihalomethanes in treated water due to the presence of free chlorine Preservation with sodium thiosulfate to destroy excess chlorine cold storage... 

Kinetic studies of the substitution reaction of 2-chloro-l-methylpyridinium iodide with phenoxides are consistent with the SnAt mechanism, with rate-determining nucleophilic attack.38 The effects of a variety of ring substituents on the reactivities of 2-fluoro- and 2-chloro-pyridines in reactions with sodium ethoxide in ethanol have been examined. The results were discussed in terms of the combination of steric, inductive, and repulsive interactions.39 Substitution in 2,4,6-trihalopyridines normally occurs preferentially at the 4-position. However, the presence of a trialkylsilyl group at the 3-position has been shown to suppress reaction at adjacent positions, allowing substitution at the 6-position.40 Methods have been reported for the introduction and removal of fluorine atoms for polyfluoropyridines. Additional fluorine atoms were introduced by metallation, chlorination, and then fluorodechlorination, while selective removal of fluorine was achieved by reduction with either metals or complex hydrides or alternatively by substitution by hydrazine followed by dehydrogena-tion-dediazotization.41... 

The reaction of 0,jV,-dimethyllythranidine (77) with phosphoryl chloride in pyridine followed by catalytic hydrogenation gave a crystalline chloro compound (83) as a major product and an amorphous dichloroderivative (84). Both products underwent hydrogenolysis of the chlorine atom with sodium in iso- and //-propyl alcohol, respectively, to yield bisdcoxy-CUV-dimethyllythranidine (85). 

Another herbicide, 2,4,5-trichlorophenoxyacetic acid, is synthesized by starting with the chlorination of benzene to give 1,2,4,5-tetrachloroben-zene, which reacts with caustic to give 2,4,5-trichlorophenol. Conversion to the sodium salt followed by reaction with sodium chloroacetate and acidification gives 2,4,5-trichlorophenoxyacetic acid. Agent Orange is a 1-to-l mixture of the butyl esters of 2,4,5-trichlorophenoxyacetic acid and 2,4,-dichlorophenoxyacetic acid. 

Methylchromones and chromone-2-carbaldehyde are converted to 3-chlorochromones in good yield upon reaction with sodium hypochlorite (Scheme 49). The selective substitution of chlorine at C-3 is considered to involve the addition of NaO Cl1 to the C(2)-C(3) double bond followed by elimination of NaOH <1998SC3827>. 

When trichloropyrazine is treated with ammonia under pressure, 2-amino-3,5-dichloropyrazine (101) is formed.273 This, on reaction with sodium methoxide, gives the 3-methoxy derivative (104). When trichloropyrazine is allowed to react with aqueous ammonia at 80° for 15 hours, the 3-chlorine is displaced to give compound 100. The latter... 

A 20% transformation of the phylloporphyrin 43 into the chlorin 44 with sodium ethoxide at 185°C was reported (29LA(471)146). The structure of 44 was proved correct by X-ray crystallography (69MI1). Obviously, a steric interaction between peripheral substituents causes the driving force for the reaction, which otherwise is difficult to understand. 

Chlorine dioxide is manufactured on site as the gas cannot be stored in compressed form it is explosive under pressure. Several methods are used to generate chlorine dioxide. The most common method involves the reaction of chlorine gas with sodium chlorite to form chlorine dioxide and sodium chloride ... 

When we compare vinyl chloride CH2=CHC1 with ethyl chloride CH3—CH2C1, there appears to be a very important difference in the properties of the C—Cl bond. The chlorine atom in the first case is unreplaceable or at least replaceable with extreme difficulty, for example by hydroxyl (saponification), a process which proceeds very readily with ethyl chloride. Vinyl chloride also appears to be less reactive in the reaction with sodium vapour in the dilute flame, that is the activation energy is higher. 

The 2,6-dichloropyrogallol structure (7), which is produced by chlorination of the syringyl nucleus (3), is thereafter transformed to a colored material of unknown structure on reaction with sodium sulfite. 

The mechanism of displacement of chlorine and bromine by fluoride from the side chain of these systems is of interest. It has been suggested that an Sn2 type of displacement of fluorine from 3-trifluoromethylquinoline occurs in reactions with sodium eth-oxide [141] (Figure 9.55), and a similar process could account for the displacements of chloride or bromide by fluoride from 9.54A that were indicated in Figure 9.54. 

SAFETY PROFILE MHdly toxic by ingesdon and inhalation. Human mutation data reported. Flammable. Strongly exothermic reaction with sodium dimethylsulfinate. When heated to decomposition it emits toxic fumes of F" and Cr. See also CHLORINATED HYDROCARBONS, AROMATIC and FLUORIDES. 

The bulk material may ignite or explode in storage. Traces of water may initiate the reaction. A rapid exothermic decomposition above 175°C releases oxygen and chlorine. Moderately explosive in its solid form when heated. Explosive reaction with acetic acid + potassium cyanide, amines, ammonium chloride, carbon or charcoal + heat, carbon tetrachloride + heat, N,N-dichloromethyl-amine + heat, ethanol, methanol, iron oxide, rust, 1-propanethiol, isobutanethiol, turpentine. Potentially explosive reaction with sodium hydrogen sulfate + starch + sodium carbonate. Reaction with acetylene or nitrogenous bases forms explosive products. 

---