Question

Identify the compound: molecular mass 113; gives a positive hydroxamate test, which indicates the presence of either an acyl chloride or an ester; ir: 2237, 1733, 1200 cm–1; 1h nmr: δ 1.33 (3h, t, j = 7 hz), δ 3.45 (2h, s), δ 4.27 (2h, q, j = 7 hz).

Answer 1

It took a bit longer to solve this problem. I am attempting it to the best of my knowledge. If you have any question please feel free to ask.I concluded the structure below on the basis of following information,

1) On the basis of molecular mass i concluded that molecules with odd molecular mass contain odd number of nitrogen atoms, so I included only one nitrogen in structure.

2) The signal at around 2237 cm-1 in IR indicates the presence of carbon triple bond carbon or nitrile group. I selected nitrile because in selection of carbon triple bond carbon the nitogen should have 2 protons (-NH2) which should give a singlet peak around 6-7 ppm in NMR which is not present in data.

3) I selected ethoxide, because the CH3 group which is more shielded (1.33 ppm) as compare to CH2 gives signal in upfield while CH2 directly attached to oxygen id deshielded and give signal in downfield (i.e 4.27 ppm).
4) The signal for a singlet peak and 2 protons was assigned to CH2 group between carbonyl group and nitrile group because it is deshielded (3.45 ppm) because it is attached to two electron withdrawing groups.
Hope I have correctly elucidated the data.