Phthalimide

Phthalimide

Names
IUPAC name Isoindole-1,3-dione
Other names 1,3-dioxoisoindoline Phthalimidoyl (deprotonated)
Identifiers
CAS Number	85-41-6 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:38817 Y
ChEMBL	ChEMBL277294 Y
ChemSpider	6550 Y
ECHA InfoCard	100.001.458
PubChem	6809
InChI InChI=1S/C8H5NO2/c10-7-5-3-1-2-4-6(5)8(11)9-7/h1-4H,(H,9,10,11) Y Key: XKJCHHZQLQNZHY-UHFFFAOYSA-N Y InChI=1/C8H5NO2/c10-7-5-3-1-2-4-6(5)8(11)9-7/h1-4H,(H,9,10,11) Key: XKJCHHZQLQNZHY-UHFFFAOYAS
SMILES O=C2c1ccccc1C(=O)N2
Properties
Chemical formula	C8H5NO2
Molar mass	147.13 g·mol−1
Appearance	White solid
Melting point	238 °C (460 °F; 511 K)
Boiling point	336 °C (637 °F; 609 K) sublimes
Solubility in water	<0.1 g/100 ml (19.5 °C)
Acidity (pKa)	8.3
Basicity (pKb)	5.7
Magnetic susceptibility (χ)	-78.4·10−6 cm3/mol
Related compounds
Related Amides	Maleimide
Related compounds	Phthalic anhydride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Phthalimide is the organic compound with the formula C₆H₄(CO)₂NH. It is the imide derivative of phthalic anhydride. It is a sublimable white solid that is slightly soluble in water but more so upon addition of base. It is used as a precursor to other organic compounds as a masked source of ammonia.

Phthalimide can be prepared by heating phthalic anhydride with aqueous ammonia giving 95-97% yield. Alternatively, it may be prepared by treating the anhydride with ammonium carbonate or urea. It can also be produced by ammoxidation of ortho-xylene.

Phthalimide is used as a precursor to anthranilic acid, a precursor to azo dyes and saccharin.

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". Alkyl halides can be converted to the N-alkylphthalimide:

The amine is commonly liberated using hydrazine:

Dimethylamine can also be used.

Some examples of Phthalimide drugs include Thalidomide, Amphotalide, Taltrimide & Talmetoprim.

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 flanking electrophilic carbonyl groups. Potassium phthalimide, made by reacting phthalimide with potassium carbonate in water at 100 °C or with potassium hydroxide in absolute ethanol, is used in the Gabriel synthesis of primary amines, such as glycine.