Advanced Pharmaceutical Analysis 13 C NMR Examples Lecture 7 58 Advanced Pharmaceutical Analysis 13 C NMR Examples Check 3 Dr. Baraa Ramzi

Example 1 A compound with the formula C3H6O2 gives the following proton-decoupled and off-resonance-decoupled spectra. Determine the structure of the compound.

Example 1 C3H6O2 IHD=1

Example 1 C3H6O2 Looks like carboxylic acid IHD=1

Example 2 Following are proton-decoupled 13C spectra for three isomeric alcohols with the formula C4H10O. An off-resonance analysis yields the multiplicities shown; s = singlet, d = doublet, t = triplet, and q = quartet. Identify the alcohol responsible for each spectrum and assign each peak to an appropriate carbon atom or atoms.

Example 2 (A) C4H10O IHD=0

Example 2 (B) C4H10O IHD=0

Example 2 (C) C4H10O IHD=0

Example 3* The following spectrum is of an ester with formula C5H8O2. Multiplicities are indicated. Draw the structure of the compound and assign each peak.

Example 3 C5H8O2 IHD=2

Example 4 Following are the 1H and 13C spectra for each of four isomeric bromoalkanes with formula C4H9Br. Assign a structure to each pair of spectra.

Example 4 (B) IHD=0

Example 4 (C) IHD=0

Example 4 (D) IHD=0

Example 5 Following are the 1H and 13C spectra for each of three isomeric ketones with formula C7H14O. Assign a structure to each pair of spectra.

Example 5 (A) IHD=1

Example 5 (B) IHD=1

Example 5 (C) IHD=1

Example 6 The proton NMR spectrum for a compound with formula C5H12O2 is shown below. The normal carbon-13 NMR spectrum has three peaks. The DEPT-135 and DEPT-90 spectral results are tabulated. Draw the structure of this compound.

Example 6 IHD=0

Example 7 * The proton NMR spectrum for a compound with formula C5H10O is shown below. The normal carbon-13 NMR spectrum has three peaks. The DEPT-135 and DEPT-90 spectral results are tabulated. Draw the structure of this compound.

Example 7 IHD=1

Example 8 The proton NMR spectrum for a compound with formula C5H10O3 is shown below. The normal carbon-13 NMR spectrum has four peaks. The infrared spectrum has a strong band at 1728 cm−1. The DEPT-135 and DEPT-90 spectral results are tabulated. Draw the structure of this compound.

Example 8 IHD=1

Example 9 The proton NMR spectrum for a compound with formula C9H8O is shown below. The normal carbon-13 NMR spectrum has five peaks. The infrared spectrum has a strong band at 1746 cm -1 . The DEPT-135 and DEPT-90 spectral results are tabulated. Draw the structure of this compound.

Example 9 IHD=6

Example 10 * The proton NMR spectrum for a compound with formula C10H12O2 is shown below. The infrared spectrum has a strong band at 1711 cm−1. The normal carbon-13 NMR spectral results are tabulated along with the DEPT-135 and DEPT-90 information. Draw the structure of this compound. 2 pssibilities

Example 10 IHD=5

Example 11 The proton NMR spectrum of a compound with formula C7H12O3 is shown. The infrared spectrum displays strong bands at 1720 and 1738 cm−1 . The normal carbon-13 and the DEPT experimental results are tabulated. Draw the structure of this compound.

Example 11 IHD=2

Example 12 The proton NMR spectrum is shown for a compound with formula C5H9NO4. The infrared spectrum displays strong band at 1750 cm−1. The normal carbon-13 and the DEPT experimental results are tabulated. Draw the structure of this compound.

Example 12 IHD=2

Example 13 The proton NMR spectrum of a compound with formula C6H5NCl2 is shown. The normal carbon-13 and the DEPT experimental results are tabulated. The infrared spectrum shows peaks at 3432 and 3313 cm-1 and a series of medium-sized peaks between 1618 and 1466 cm-1. Draw the structure of this compound.

Example 13 IHD=4 Test them + position

Example 14 A compound has the chemical formula of C4H8O determine its structure using provided spectra.

Example 14 C4H𝟖O IHD=1

Example 14 C4H𝟖O IHD=1

Example 14 C4H𝟖O IHD=1

Example 15 A compound has the chemical formula of C4H6NBr determine its structure using provided spectra.

Example 15 C4H6NBr IHD=2

Example 15 C4H6NBr IHD=2

Example 15 C4H6NBr IHD=2

Example 16 A compound has the chemical formula of C5H8O determine its structure using provided spectra.

Example 16 C5H𝟖O IHD=2

Example 16 C5H𝟖O IHD=2

Example 16 C5H𝟖O IHD=2