Table 2.
Benzoquinoid type ions in the spectra of derivatives or para-aminobenzoic acids.
| Compound | m/z (Rel. %) | Ion structure |
|---|---|---|
| 4-Aminobenzoic acid, N-methoxycarbonyl- | 108 (10) | HO+=C6H4=NH |
| 4-Aminobenzoic acid, N-ethoxycarbonyl- | 108 (18) | |
| 4-Aminobenzoic acid, N- n-propyloxycarbonyl- | 108 (13) | |
| 4-Aminobenzoic acid, N-isopropyloxycarbonyl- | 108 (15) | |
| Methyl 4-(methoxycarbonylamino)benzoate | 122 (19) | CH3O+=C6H4=NH |
| Methyl 4-(ethoxycarbonylamino)benzoate | 122 (17) | |
| Methyl 4-(n-propyloxycarbonyl amino)benzoate | 122 (13) | |
| Methyl 4-(isopropyloxycarbonylamino)benzoate | 122 (10) | |
| Methyl 4-(trifluoroacetylamino)benzoate | 122 (8) | |
| Methyl 4-(pentafuoropropionylamino)benzoate | 122 (9) | |
| Methyl 4-(heptafluorobutyrylthio)benzoate | 122 (14) | |
| Methyl 4-(acetylamino)benzoate | 122 (3) | |
| Trifluoroacetyl 4-(trifluoroacetylamino)benzoyl anhydride | 176 (.8) | CF3O+=C6H4=NH |
| Pentafluoropropionyl 4-(pentafluoropropionylamino) benzoyl anhydride | 226 (.5) | C2F5O+=C6H4=NH |
| Heptafluorobutyryl 4-(heptafluorobutyrylamino) benzoyl anhydride | 276 (.5) | C3F7O+=C6H4=NH |