Annotate the NMR spectra. Assign the hydrogens to the structure of methyl 3-nitrobenzoate.

An amine of unknown structure contains one nitrogen and nine carbon atoms. The 13C-NMR spectrum shows only five signals, all between 20 and 60 ppm. Three cycles of Hofmann elimination sequence [(1) CH3I; (2) Ag2O, H3O; (3) heat] give trimethylamine and 1,4,8-nonatriene. Propose a structural formula for the amine.

Propose a synthesis for 3,5-dibromo-2-hydroxybenzoic acid (3,5-dibromosalicylic acid) from phenol.

Name the following compounds A and B. How could you distinguish these two molecules by using 1H NMR and IR techniques? Propose an analytical technique to determine the iron content of these compounds. Calculate the mass percentages of C and H of compound B (C: 12.01 g/mol; H: 1.008 g/mol; Fe: 55.845 g/mol).

How would you use IR and ¹H-NMR spectroscopy to distinguish between these two isomeric compounds? For IR, consider the absorption of the carbonyl group. For ¹H-NMR, consider the number of signals observed. Select the IR frequency and number of NMR signals that is diagnostic for either isomer a or isomer b. Isomer A: cyclopentanecarboxamide Isomer B: 6-hydroxyhexanenitrile IR: ¹H-NMR: cm-1. a-4 a-5 b-3 b-4 b-5 b-6 signals a-1680 a-1690 a-1735 a-1810 a-2250 b-1650 b-1690 b-1710 b-2250 24

As a method for the synthesis of cinnamaldehyde (3-phenyl-2-propenal), a chemist treated 3-phenyl-2-propen-1-ol with K2Cr2O7 in sulfuric acid. The product obtained from the reaction gave a signal at δ5 in its 13C NMR spectrum. Alternatively, when the chemist treated 3-phenyl-2-propen-1-ol with PCC in CH2Cl2, the 13C NMR spectrum of the product displayed a signal at δ193.8. (All other signals in the spectra of both compounds appeared at similar chemical shifts.) (a) Which reaction produced cinnamaldehyde? (b) What was the other product?