Question

1. Please provide the MS and Dept 45,90, 135 Spectra values of Benzoic Acid, 3-bromo-, methyl ester. Also discuss on how the results were obtained. 

For Ex: MS for 3-(3-methoxyphenyl) propanoic acid, will be written like this. 

MS: M/z (EI), 182 (M+2), 180 (M+), 165 (M+ -CH3), 149 (M+ - CH3-O), 135 (M+ COOH), 121 (M+- COOH-CH2), 107 (M+- COOH-CH2-CH2), 91 (M+ - COOH-CH2-CH3-O), 77(M+- COOH-CH-Ch2-Ch3-O Aromatic).

For ex the Discussion would be like this:

The molecular ion (M+) peak is at 180 m/z meaning that the molecule weight of the unknown molecule is around 180 g/ml. The spectrum has also confirmed a M+2 Peak at 182 m/z which represent the isotopes. The base peak is located at peak 135 m/z representing the loss of m-45 which is a loss of carboxylic acid meaning that this fragment is the most important one. The low peak at 165 m/z confirms the loss of the CH3 group. The peak 149 m/z which is low intensity shows the loss of ether group (OCH3, M-31). Both peaks, 121 and 107 m/z show the loss of the two CH2 groups.