Q6(i). C₃H₇NO with two N–methyl singlets: N,N-dimethylformamide
In the PMR (¹H) spectrum recorded at 293 K, an organic compound C₃H₇NO exhibited signals at δ 7.8 (1H, s), 2.8 (3H, s) and 2.6 (3H, s). Identify the structure of the compound and explain your answer.
Answer in brief
N,N-Dimethylformamide (DMF), HCON(CH₃)₂; the two N–CH₃ groups differ at 293 K because rotation about the C–N bond is slow.
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CoversNMRDMFrestricted rotationamide C–N bondcoalescence temperature
All parts of Question 6
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- 6(f) trans- and cis-Cyclohexane-1,2-diol from cyclohexanone4 marks
- 6(g) [1,5]-Carbon shift and Cope rearrangement4 marks
- 6(h) Four C₁₀H₁₄ isomers: the one marked by a McLafferty peak4 marks
- 6(i) C₃H₇NO with two N–methyl singlets: N,N-dimethylformamide4 marks
- 6(j) ν(C=C) of methylidenecycloalkanes and ring size4 marks