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 Phthalimide Powder | |
| Names | |
|---|---|
| Preferred IUPAC name 1H-Isoindole-1,3(2H)-dione | |
| Other names 1,3-dioxoisoindoline Phthalimidoyl (deprotonated) | |
| Identifiers | |
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3D model (JSmol) | |
| ChEBI | |
| ChEMBL | |
| ChemSpider |
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| ECHA InfoCard | 100.001.458 |
| UNII | |
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| Properties[1] | |
| C8H5NO2 | |
| Molar mass | 147.133 g·mol−1 |
| Appearance | White solid |
| Melting point | 238 °C (460 °F; 511 K) |
| Boiling point | 336 °C (637 °F; 609 K) sublimes |
| <0.1 g/100 ml (19.5 °C) | |
| Acidity (pKa) | 8.3 |
| Basicity (pKb) | 5.7 |
| −78.4×10−6 cm3/mol | |
| Related compounds | |
RelatedAmides | Maleimide |
Related compounds | Phthalic anhydride |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Phthalimide is theorganic compound with the formula C6H4(CO)2NH. It is theimide derivative ofphthalic anhydride. It is asublimable white solid that is slightly soluble in water but more so upon addition ofbase. It is used as a precursor to other organic compounds as a masked source ofammonia.[2]
Phthalimide is used as a precursor toanthranilic acid, a precursor toazo dyes andsaccharin.[2]
Alkyl phthalimides are useful precursors to amines in chemical synthesis, especially in peptide synthesis where they are used "to block both hydrogens and avoid racemization of the substrates".[4] Alkyl halides can be converted to the N-alkylphthalimide:
The amine is commonly liberated using hydrazine:
Dimethylamine can also be used.[5]
Some examples of phthalimide drugs includethalidomide,amphotalide,taltrimide,talmetoprim, andapremilast. With a trichloromethylthio substituent, a phthalimide-derived fungicide isFolpet.
It forms salts upon treatment with bases such as sodium hydroxide. The high acidity of the imido N-H is the result of the pair of flankingelectrophilic carbonyl groups.Potassium phthalimide, made by reacting phthalimide withpotassium carbonate in water at 100 °C or withpotassium hydroxide in absolute ethanol,[6] is used in theGabriel synthesis of primary amines, such asglycine.
Phthalimide can be prepared by heatingphthalic anhydride with alcoholic ammonia giving 95–97% yield. Alternatively, it may be prepared by treating the anhydride withammonium carbonate orurea. It can also be produced byammoxidation ofo-xylene.[2]
Phthalimide can also be prepared fromphthalic acid by the following process:
Carboxylic acids when reacted with ammonia give ammonium salts, which in turn give amides when strongly heated.
Kladnoite is a natural mineral analog of phthalimide.[7] It is very rarely found among a few burningcoal fire sites.
Phthalimide has low acute toxicity withLD50 (rat, oral) of greater than 5,000 mg/kg.[2]
