Exercises for chapter

Deduce a structure for the product C9HJ3N3 produced by reacting pyridine with the potassium salt of Me2N(CH2 2NH2. 

Deduce structures for the product formed by (i) reacting 2-chloropyridine with (a) hydrazine — C3H2N3, (b) water — C3H5NO (ii) 4-nitropyridine heated with water at 60°C — C5H5NO. 

Deduce structures for the products formed in turn by reacting 4-chloropyri-dine with (i) sodium methoxide — C H NO, A, this with iodomethane — C HjqINO, then this heated at 185°C — C H NO, isomeric with A. 

Treatment of 4-bromopyridine with NaNH2 in NH3 (liq.) gives two products (isomers, C5H N2) but reaction with sodium methoxide gives a single product, C H NO. What are the products and why is there a difference  

Write structures for the products to be expected in the following sequences (i) 4-diisopropylaminocarbonyl pyridine with LDA then with benzophe-none, then with hot acid — Cj9Hj3N02 (ii) 2-chloropyridine with LDA then iodine — C3H3CII (iii) 3-fluoropyridine with LDA then with acetone 

Suggest a structure for the final, monocyclic product of the following sequence quinolizinium bromide with LiAlH4 and then H2/Pd giving C9H13N. 

Write down the structures of the intermediates in the following synthesis of the quinolizinium cation 2-methylpyridine was reacted with LDA, then EtO(CH2)2-CH = 0 to give C11H27NO2 which was heated with HI (— C9H 2NO I ) this 

Which indolizines would be foimed from the following combinations (i) 2-picoline with (a) BrCHjCO.Me/NaHCOj, (b) MeCHBrCHO/NaHCOa (ii) What would be the products if the 2-picoline was replaced by 2-aminopyridine  

Deduce the structures of intermediates and final product in the following sequence 5-methoxy-2-methylpyridine reacted with KNH2//-AmONO C7H8N2O2 then this with Zn/AcOH — C7H10N2O, and finally this with HC02Me/PPE (polyphosphate ester) — CgH8N20. 

Imidazo[l,5-a]pyridine, on reaction with aqueous HNO2 gave 3-(pyridin-2-yl)-1,2,4-oxadiazole. Suggest a mechanism. What product would be obtained by reaction of indolizine with nitrous acid  

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In the exercises for Chapter 2 we suggested calculations for several materials, including Pt in the cubic and fee crystal structures and ScAl in the CsCl structure. Repeat these calculations, this time developing numerical evidence that your results are well converged in terms of sampling k space and energy cutoff. 

In the exercises for Chapter 2, we suggested you compute the lattice constants, a and c, for hexagonal Hf. Repeat this calculation using an approach that optimizes the supercell volume and shape within your calculation. Is your result consistent with the result obtained more laboriously in Chapter 2 How large is the distortion of c/a away from the ideal spherical packing value ... 

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