Diehloro

Pyrimidine, 4,6-diehloro-2,5-dimethyl-bromination, 3, 77 Pyrimidine, 2,4-diehloro-5-methyl-selenolysis, 3, 101 Pyrimidine, 2,4-diefaloro-6-methyl-alcoholysis, 3, 100 Pyrimidine, 4,6-diefaloro-2-metfayl-reaetions... 

Several doubly eharged ions are ineluded in Seheme 9.1 some have been observed experimentally. Ionization of 3,4-diehloro-l,2,3,4-tetramethyleyclobutene in Sbp5-S02 at —75 C results in an NMR spectrum attributed to the tetramethyl derivative of the cyclobutadienyl dication ... 

However, methyl 2,2,3-trichloropropionate and chlorine monofluoride form methyl 2,3 diehloro-2-fluoropropionate An additional equivalent of chlorine monofluoride selectively generates methyl 3-chloro-2,2-difluoropropionate [7i] (equation 15)... 

Oxidations of pyridopyrimidines are rare, but the covalent hydrates of the parent compounds undergo oxidation with hydrogen peroxide to yield the corresponding pyridopyrimidin-4(3 T)-ones. Dehydrogenation of dihydropyrido[2,3-(i]pyrimidines by means of palladized charcoal, rhodium on alumina, or 2,3-diehloro-5,6-dicyano-p-benzo-quinone (DDQ) to yield the aromatic derivatives have been reported. Thus, 7-amino-5,6-dihydro-1,3-diethylpyrido[2,3-d]-pyri-midine-2,4(lif,3f/)-dione (177) is aromatized (178) when treated with palladized charcoal in refluxing toluene for 24 hours. 

Taking into account the high reactivity of the ehloro atoms in 2-ehloro-3-nitro- (99a, 99d, and 99f), 7-ehloro-3-nitro- (99e and 99g), 2,7-diehloro-3-nitro- (99c), and 2-ehloro-3,6-dinitro-l,8-naphthyridines (99b), a great variety of 2- (or 7-) substituted amino produets [99, = NHCH3, N(CH3)Ph,... 

Wlien more than one oxo (hydroxy) group is present, a mixture of ehloro-hydroxy- and diehloro-naphthyridines is usually formed. Tlius, reflux of 3-nitro-l,8-naphthyridin-2,7(lH,8H)-dione (114) with phosphorus oxy-ehloride gives the three halogeno eompounds (115,116, and 117), the ratio being dependent on the reaetion time (94EJMC735). 

Cyclization of ethyl A -(2-pyridyl)-2-methyl)- and A -(5-ehloro-2-pyridyl)-malonamates in a mixture of POCI3 and PPA at 130°C gave 2-ehloro-3-methyl- and 2,7-diehloro-4/7-pyrido[l,2-n]pyrimidin-4-ones in 26 and 61% yields, respeetively (00BMC751). 

Likewise, 5-phenyl-1/7-3-benzazepin-2(3//)-ones, e.g. 32, prepared by dehydrogenation of the tetrahydro derivatives 31 with 2,3-diehloro-5,6-dieyano-l,4-benzoquinone (DDQ), on treatment with Meerwein s reagent yield the 2-ethoxy derivatives, e.g. 33, which undergo facile aminodeethoxylation with a variety of amines.211... 

No studies were located regarding cancer efFeets in animals after inhalation exposure to 3,3 -diehloro-benzidine. However, cancer effects have been observed in animal studies where 3,3 -dichlorobenzidine was administered orally or by other routes. See Seetions 2.2.2.8 and 2.5 for further information. 

No aeute-duration oral MRL was ealeulated for 3,3 -diehlorobenzidine because the available studies did not identify appropriate NOAELs or LOAELs (Ashby and Mohammed 1988 Bimer et al. 1990 Cihak and Vontorkova 1987 Ghosal and Iba 1990). No intermediate-duration oral MRL was calculated for 3,3 -dichlorobenzidine beeause the available studies did not identify relevant noncancer effects (Ito et al. 1983 Osanai 1976 Pliss 1959, 1963). No ehronie-duration oral MRL was ealeulated for 3,3 -diehloro-benzidine because there were no NOAELs identified below the lowest available serious LOAEL for convulsions and slight neuronal degeneration in dogs (Stula et al. 1978). 

Death. No deaths were reported in humans from inhalation, oral, or dermal exposure to 3,3 -diehloro-benzidine. In animals, 3,3 -dichlorobenzidine eaused no deaths in rats exposed by the inhalation route in eoneentrations as high as 23,700 mg/m for 2 hours per day for 7 days (Gerarde and Gerarde 1974). In addition, the estimated aeute oral LDjg for rats (7,070 mg/kg for the free base and 3,820 mg/kg for the dihydroehloride salt) and the minimum dermal lethal dose for male and female New Zealand albino rabbits (>8,000 mg/kg) for 3,3 -diehlorobenzidine suggested that the lethal toxieity of 3,3 -dichlorobenzidine is minimal (Gerarde and Gerarde 1974). Consequently, it is unlikely that death will oeeur in humans exposed to 3,3 -diehlorobenzidine at the levels at whieh it oeeurs at hazardous waste sites. 

Gastrointestinal Effects. Gastrointestinal upset was one of the symptoms reported by employees who worked with 3,3 -diehlorobenzidine dihydroehloride (dihydro salt of 3,3 -diehlorobenzidine) (Gerarde and Gerarde 1974). However, there is no eonelusive evidence that 3,3 -dichlorobenzidine eaused these gastrointestinal upsets since there was exposure to other chemieals as well. In addition, 3,3 -diehloro-benzidine has not been found to eause any of these effects in experimental animals. Therefore, it is unlikely that exposure to 3,3 -diehlorobenzidine at hazardous waste sites will cause gastrointestinal effeets in humans. 

Dichlorobenzidine was not deteeted in the ambient air at production facilities at deteetion limits of 0.1-5.0 ng/m (Narang et al. 1982 Riggin et al. 1983). The median concentration of 3,3 -diehloro-benzidine in waste effluents (<10 ppb), groundwater (<10 ppb), surface water (<10 ppb), and soils (<1 ppb) is very low, although significant contamination may be associated with hazardous waste sites (Staples et al. 1985). Moreover, the production and use of 3,3 -diehlorobenzidine-based dyes has decreased to zero over the last 30 years, while environmental and health regulations have been implemented to reduce the release of 3,3 -dichlorobenzidine to the environment. 

Die Reaktion von 1,2-Propandiol mit Dimethylamin unter gleichen Bedingungen liefert mit Diehloro-tris-[triphenylphosphan]-ruthenium ein Gemiseh von 2-Dimethylamino-pro-... 

This monomer polymerizes too rapidly in the presence of free radicals to copolymerize easily with most vinyl monomers. However, it readily forms copolymers with 2,3-diehloro-i,3-butadiene, which also is a monomer that polymerizes very rapidly. 

Oxalato-diethylenediamino- Diehloro-dietliyfenediamino- Dibromo-diethylcncdianiino-chromic complex. chromic complex. chromic complex . 

Cr en2pn](SCN)3.pi20, is prepared by heating m-diehloro-dicthyl-enediamino-cliromic chloride, [Cr en2Cl2]01, with propylcnediaminc monohydrate on a water-bath for some time until the mass becomes yellow. It is then cooled, treated with a little water, filtered, and a concentrated aqueous solution of ammonium thiocyanate added to the filtrate. Small yellow crystals separate, which are recrystallised from warm water. They are soluble in water and insoluble in alcohol.1... 

Of the hexaquo-salts, hexaquo-chromic chloride, [Cr(H20)6]Cl3, lia.s been most thoroughly examined it is isomeric with chloro-pentaquo-chromic chloride, [Cr(H20)5Cl]Cl2-H20, and diehloro-tetraquo-chromic chloride, [Cr(H20)4Cl2]C1.2H20. The salts differ in colour and in ioirisable acidic radicle. 

If an aqueous solution of green irans-diehloro-chloride is left to stand for one or two days the colour changes to red, and on evaporation, after addition of acetic acid, a residue is obtained from which a considerable quantity of isomeric violet eis-dichloro-chloride may be obtained. The change from cis- into iraas-salt is accomplished by evaporating several times an aqueous solution of the violet isomer after addition of hydrochloric acid and mercuric chloride. 

Cis- and frares-dithiocyanato-salts are transformed one into the other through the diehloro-salts, according to the following scheme —... 

The bromide, [Cr en2Cla]Br.H20, is obtained from the chloride by adding concentrated hydrobromic acid to a concentrated aqueous solution of the as-diehloro-chloride. It crystallises in violet needles which are less soluble in water than the chloride, and lose water at 100° C. without change of colour. 

The sulphate, [Cr en2CI 2]S04H, is obtained by decomposing cis-diehloro-diethylenediamino-chromie thiocyanate with sulphuric acid, when the acid sulphate crystallises in violet needles. 

Optical Activity in the Series.—Another type of isomerism is possible in the series, for the as-diehloro-salts present a case of molecular asymmetry similar to that observed in 1-, 2-dinitro-diethylenediamino-cobalt salts. Two configurations are possible, the one being the mirror image of the other, thus ... 

The diehloro-salts are obtained from the camphor sulphonate by the action of hydrochloric acid. 

Dibromo-diethylenediamino-chromic Salts, [Cren2Br2]R.— These, like the dichloro-salts, exist in isomeric forms, namely, violet cis-salts and green trans-salts. There should also exist, reasoning from analogy with diehloro-diethylenediamino-ehromic salts, two optically active modifications corresponding to the d- and 1-dichloro-compounds of the m-series, but so far they have not been prepared. 

Dibromo-aquo-triammino-chromic Salts, [Cr(NII3)3H2OBr2]R, are crystalline, intensely green substances which are somewhat soluble in water, giving a green liquid which soon changes to bluish red. They are assumed to belong to the trans-series, because they correspond completely in colour with the frans-diehloro- and iran. -dibromo-diethylenediamino-chromic salts.2... 

That is, a mixture of 1-, 2-diaquo-tetrammino-cobaltic chloride and 1-, 2-diehloro-tetranimino-cobaltic chloride is formed. The aquo-salt is readily soluble in water but the diehloro-salt sparingly so. The last named forms intense blue crystals which are contaminated with small quantities of the praseo-salt, from which it may be freed by transforming it into the dithionate. The dithionate is practically insoluble, but the chloride may be regenerated from it by rubbing it with ammonium chloride. The bromide, the iodide, and the nitrate have all been prepared. 

The crude substance is their recrystallised from water containing acetic acid. The compound was originally believed to exist in two isomeric forms, but Jorgensen found the crystalline form depends on the concentration of acetic acid used for crystallisation, inasmuch as rhombic leaflets separate from hot dilute acetic acid, and from hot concentrated acid the substance separates in yellow-brown needles. The complex is sparingly soluble in water, and gives no precipitate in aqueous solution with silver nitrate or potassium chromate. If treated with cold hydrochloric acid it is transformed into chloro-dinitro-triammino cobalt, [Co(NH3)3(N02)2Cl], and if warmed with concentrated hydrochloric acid gives diehloro-aquo-triammino-cobaltic chloride. 

The compound is slightly soluble in cold water and easily soluble in hot water. If heated with hydrochloric acid for a considerable time it decomposes into chloro-pentammino-cobaltic chloride and diehloro-tetrammino-cobaltie chloride. It crystallises in glistening brownish-red prisms. 

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