Dibromopentane

Bromo-l-phthalimidopentane 3 was obtained in 72-82 g yield by refluxing 92 g of 1,4-dibromopentane 1, 55.5 g of potassium phthalimide 2, and 200 mL dry acetone on a steam bath for 30 h. Compound 3 (30 g) and 42 g 6-methoxy-8-aminoquinoline 4 refluxed at 130-135 °C for 6 h, extracted with benzene to separate insoluble 6-methoxy-8-aminoquinoline hydrobromide, the residue from evaporation of the benzene was refluxed with stirring with 100 mL of an alcoholic solution of 6 g hydrazine hydrate for 4 h, the solution was concentrated, made acidic to Congo red with 8 N hydrochloric acid, filtered, and washed with boiling water. The combined filtrate and washings was concentrated, made alkaline, extracted with benzene, and distilled in vacuo to give 20.5 g primaquine 6, which was treated with 19 mL 85% phosphoric acid in absolute ethanol, formed 42.5% primaquine diphosphate. 

Scheme 45. Reaction conditions i, LDA ii, "BuBr iii, 1,4-dibromopentane iv, TMSI v, NajCOa-MeOH vi, H2-Pt02-...

The increments of Table 4.78 permit a prediction of carbon shifts in substituted alkanes. Thereby, they may provide an assignment aid which is particularly useful when proton decoupling experiments (off-resonance, gated, selective) and the application of modern pulse sequences fail because of equal multiplicities (( —CH2 —)n chains) or signal overcrowding in the i3C and iH NMR spectra. The practical use of the increments is illustrated for 1,4-dibromopentane and lysine. 

Nickelapentacycles have also been prepared by the reaction of 1,4-dihaloalkanes such as 1,4-dibromobutane or 1,4-dibromopentane with Ni(COD)(bipy) (bipy = 2,2 -bipyridyl) to afford complexes of type 71 as dark green crystalline... 

Bromo-5-phthalimido pentane is prepared by the interaction of 1, 4-dibromopentane with potassium phthalimide, which on reaction with 8-amino-6-methoxy quinoline yields the condensed product. Further treatment with hydrazine eliminates the phthalimido residue and yields the primaquine base which on reaction with a double molar quantity of phosphoric acid forms the official compoimd. 

The reaction shown, when carried out with 1,4-dibromopentane, is the first step in the synthesis of the antimalarial drug primaquine, it proceeds by an S 2 mechanism and gives a compound having the molecular formula Ci3Hi4BrN02. What is this compound ... 

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