Table 3.
Benzoquinoid type ions in the spectra of derivatives of para-hydroxybenzoic acids.
| Compound | m/z (Rel. %) | Ion structure |
|---|---|---|
| 4-(Trifluoroacetyloxy)benzoic acid | 109 (10) | HO+=C6H4=O |
| 4-Hydroxybenzoic acid, N-methoxycarbonyl- | 109 (10) | |
| 4-Hydroxybenzoic acid, N-ethoxycarbonyl- | 109 (4) | |
| 4-Hydroxybenzoic acid, N-n-propyloxycarbonyl- | 109 (3) | |
| 4-Hydroxybenzoic acid, N-isopropyloxycarbonyl- | 109 (1) | |
| Methyl 4-(methoxycarbonyloxy)benzoate | 123 (8) | CH3O+=C6H4=O |
| Methyl 4-(ethoxycarbonyloxy)benzoate | 123 (5) | |
| Methyl 4-(n-propyloxycarbonyloxy)benzoate | 123 (7) | |
| Methyl 4-(isopropyloxycarbonyloxy)benzoate | 123 (6) | |
| Methyl 4-(trifluoroacetyloxy)benzoate | 123 (5) | |
| Methyl 4-(pentafluoropropionyloxy)benzoate | 123 (10) | |
| Methyl 4-(heptafluorobutyryloxy)benzoate | 123 (15) | |
| Methyl 4-(acetyloxy)benzoate | 123 (3) | |
| Trifiuoroacetyl 4-(trifluoroacetyloxy)benzoyl anhydride | 177 (1) | CF3O+=C6H4=O |
| Pentafluoropropionyl 4-(pentafluoropropionyloxy) benzoyl anhydride | 227 (.5) | C2F5O+=C6H4=O |
| Heptafluorobutyryl 4-(heptafluorobutyryloxy) benzoyl anhydride | 277 (0.4) | C3F7O+=C6H4=O |