AQA Jan 2011 Paper 4 Q5

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do not write outside the box atenolol is an example of the type of medicine called a beta blocker these medicines are used to lower blood pressure by slowing the heart rate the structure of atenolol is shown below ch h n oh ch ch ch p ch ch ch q a give the name of each of the circled functional groups labelled j and k on the structure of atenolol shown above functional group labelled j functional group labelled k marks b the h n m r spectrum of atenolol was recorded one of the peaks in the h n m r spectrum is produced by the ch group labelled p in the structure of atenolol use table on the data sheet to suggest a range of values for this peak name the splitting pattern of this peak range of values name of splitting pattern marks c n m r spectra are recorded using samples in solution the h n m r spectrum was recorded using a solution of atenolol in cdcl c i suggest why cdcl and not chcl was used as the solvent mark c ii suggest why cdcl is a more effective solvent than ccl for polar molecules such as atenolol mark wmp jan chem do not write outside the box d the c n m r spectrum of atenolol was also recorded use the structure of atenolol given to deduce the total number of peaks in the c n m r spectrum of atenolol e mark part of the c n m r spectrum of atenolol is shown below use this spectrum and table on the data sheet where appropriate to answer the questions which follow ppm e i give the formula of the compound that is used as a standard and produces the peak at ppm in the spectrum mark e ii one of the peaks in the c n m r spectrum above is produced by the ch group labelled q in the structure of atenolol identify this peak in the spectrum by stating its value mark e iii there are three ch groups in the structure of atenolol one of these ch groups produces the peak at in the c n m r spectrum above draw a circle around this ch group in the structure of atenolol shown below ch ch oh ch ch ch ch ch h n question continues on the next page mark turn over wmp jan chem do not write outside the box f atenolol is produced industrially as a racemate an equimolar mixture of two enantiomers by reduction of a ketone both enantiomers are able to lower blood pressure however recent research has shown that one enantiomer is preferred in medicines f i suggest a reducing agent that could reduce a ketone to form atenolol mark f ii draw a circle around the asymmetric carbon atom in the structure of atenolol shown below ch ch oh ch ch ch ch ch h n mark f iii suggest how you could show that the atenolol produced by reduction of a ketone was a racemate and not a single enantiomer marks f iv suggest one advantage and one disadvantage of using a racemate rather than a single enantiomer in medicines advantage disadvantage marks wmp jan chem turn over for the next question do not write on this page answer in the spaces provided turn over wmp jan chem

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