Propane 1,3-dibromo-: alkylation with

Alkylation of chiral MofNOblSjCf.fLh 2 with racemic 1,2-dibromo-propane or 1,2-dibromobutane gives diastereospecifically the pair of [Mo(NO)2(RS4)] enantiomers with equatorial R substituents (Eq. 17) (20). (This pair is one out of four theoretically possible pairs of diaster-eomeric enantiomers.)... 

Benzo[c]cinnoline is a weak base with a of 2.2 in water and 1.6 in 50% aqueous ethanol.Cryoscopic measurements show that it is dipro-tonated to some extent in 100% sulfuric acid. Well-defined quaternary salts result from heating benzo[c]cinnoline with alkyl halides and sul-fates. These are reported to decompose on treatment with ammonia, regenerating benzo[c]cinnoline, but apparently nucleophilic displacements of halogen by amines have been carried out on certain highly substituted examples in the synthesis of cationic dyestuffs. Quaternizations of benzo[c]cinnoline with a,a)-dibromo-propane and -butane are accompanied by hydrogen bromide elimination to give the cyclic iminium salts 40 and 41. When 40 is dehydrogenated, or merely refluxed in ethanol. 

The cyclic alkylation of l,2-phenylenebis(phosphine) in the complex (152) with 1,3-dibromo-propane under basic conditions gives a variety of phosphines after the displacement from the metal, including the bis(secondary phosphine) (153) and the R, S diastereomers of the bis(tertiary phosphines) (154) and (155) the crystal structure was determined of the square-planar complex unt/-[Ni (/, 5 )-(154) 2KCI04)2-CH2Cl2 <95MI 934-0l>. 

The conversion of active-methylene compounds into 2-alkylidene derivatives of 1,3-dithiolans by base-catalysed condensation with carbon disulphide followed by treatment with 1,2-dihalogenoalkanes has been further exemplified, and extended to the synthesis of substituted alkyl-idene derivatives of 1,3-diselenolans and 1,3-diselenans. With dimethyl malonate, carbon diselenide, and either 1,2-dibromoethane or 1,3-dibromo-propane, for example, the compounds (142) and (143), respectively, were formed. Analogously, the dithiolate anion obtained from deoxybenzoin... 

In later work Soulages modified the above method in respect of the stationary phase to permit the simultaneous determination of the lead alkyls and the scavengers. The copper column (150 cm x 0.4 cm) used was packed with 20% of 1,2,3-tris-(2-cyanoethoxy)-propane on Chromosorb P (30 to 60 mesh) precoated with 1% of potassium hydroxide and operated at 80°C with hydrogen (40 ml per min) as carrier gas. Recoveries were between 98 and 102% for each tetraalkyllead component in the range equivalent to 0.026 to 0.2 g of lead per litre. Similar results were obtained for the scavengers (dibromo- and dichloro-ethane). 

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