3. Other Methods of Preparation

Phthalimide has been formed by heating ammonium phthalate;[1]
by heating acid ammonium phthalate;[2] by passing dry ammonia over
heated phthalic anhydride;[3] by treating phthalyl chloride with dry
ammonia;[4] by heating phthalamide;[5] by heating phthalic anhydride
with ammonium thiocyanate;[6] by heating phthalic anhydride with
urea;[7] by heating phthalic anhydride with ammonium carbonate;[1b]
by heating phthalic acid with nitriles;[2b] by fusing _o_-cyanobenzoic
acid;[3b] and by the action of potash on _o_-cyanobenzaldehyde.[4b]


[1] Jahresb. 1868, 549; Ann. 19, 47 (1836); 41, 110 (1842); 42, 220
(1842); 205, 300 (1880); 215, 181 (1882).

[2] Jahresb. 1847-1848, 590.

[3] Am. Chem. J. 3, 29 (1881).

[4] Am. Chem. J. 3, 28 (1881).

[5] Ber. 39, 2278 (1906).

[6] Ber. 19, 1398 (1886),

[7] Ber. 10, 1166 (1877); Am. Chem. J. 18, 333 (1896);
J. Am. Chem. Soc. 32, 116 (1910); Z. angew. Chem. 32, I, 301 (1919).

[1b] J. Am. Chem. Soc. 42, 1282 (1920).