Phthalimide, potassium salt

Yield.—Almost theoretical M.P. 118°. (B., 19,2991 0. S., XIII., 82.) Reaction CXXV. Action of Alkyl Halides on Phthalimide (Potassium Salt). —When an alcoholic solution of phthalimide is treated with the theoretical quantity of caustic potash dissolved in alcohol, a crystalline compound—potassium phthalimide—separates out (see p. 427). 

EINECS 214-046-6 HSDB 5781 N-Potassiophthallmide N-Potassium phthalimide NSC 167070 Phthalimide, potassium salt Potassium phthalimidate Potassium phthalimide. 

Phthalimide with a of 8 3 can be quantitatively converted to its potassium salt with potassium hydroxide The potassium salt of phthalimide has a negatively charged nitrogen atom which acts as a nucleophile toward primary alkyl halides m a bimolecu lar nucleophilic substitution (Sn2) process... 

Alkylation of phthalimide The Gabriel synthesis (Section 22 8) The potassium salt of phthalimide reacts with alkyl hal ides to give N alkylphthalimide deriva fives Hydrolysis or hydrazinolysis of this derivative yields a primary alkylamine... 

Each of the following dihaloalkanes gives an N (haloalkyl)phthahmide on reaction with one equivalent of the potassium salt of phthalimide Write the structure of the phthahmide denvative formed m each case and explain the basis for your answer... 

Gabriel synthesis (Section 22 8) Method for the synthesis of primary alkylamines in which a key step is the formation of a carbon-nitrogen bond by alkylation of the potassium salt of phthalimide... 

Imides (e.g. phthalimide) can be purified by conversion to their potassium salts by reaction in ethanol with ethanolic potassium hydroxide. Hie imides are regenerated when the salts are hydrolysed with dilute acid. Like amides, imides readily crystallise from alcohols and, in some cases (e.g. quinolinic imide), from glacial acetic acid. 

Phthalimide, potassium [ 1H Isomdole-l,3(2//)-dione, potassium salt], 96 Phth-Gly.Gly-OEt [Glycine, N [(1,3-dihydro-1,3-dioxo-2//-isoindol-2-yl)acelyl], ethyl ester], 93 a-Pinene [Bicyclo 3.1.1]hept 2-ene,... 

Photolysis, apparatus for, 55, 17 Phthalimide, N-amino- [ 1//-Isoindole-1,3-(2//)-dione, 2-amino-, 55, 115 Potassium rew-butoxide [2-Propanol, 2-methyl-, potassium salt], 55,12, 13 Potassium iodide, 55, 71 Potassium permanganate [Permanganic acid, potassium salt], 55,68 Propane, 2,2 dimethyl 1 phenyl, 55, 112 Propane, 2 isocyano-2-methyl-, 55, 96... 

Gabriel synthesis is used for the preparation of primary amines. Phthalimide on treatment with ethanolic potassium hydroxide forms potassium salt of phthalimide which on heating with allqrl halide followed by alkaline hydrolysis produces the corresponding primary amine. Aromatic primary amines cannot be prepared by this method because aryl halides do not undergo nucleophilic substitution with the anion formed by phthalimide. 

On the preparative side, template reactions are again useful for example, the template condensation of phthalimide (or its potassium salt) with malonic acid or arylacetic acids in the presence of zinc or cadmium acetate has been shown to result in the formation of [ML] (H2L = tetrabenzoporphyrin or maso-tetraaryltetrabenzoporphyrin).1134,1135... 

An alternative reagent equivalent for the amide anion synthon is the potassium salt of phthalimide which can only react with one molecular proportion of alkyl halide. The resulting JV-alkylphthalimide is then cleaved to the primary amine (the Gabriel synthesis). The preliminary preparation of potassium phthalimide (from a solution of phthalimide in absolute ethanol and potassium hydroxide in 75% ethanol) may be avoided in some cases by boiling phthalimide with the halide in the presence of anhydrous potassium carbonate. The cleavage of the JV-substituted phthalimide is best effected by reaction with hydrazine hydrate and then heating the reaction mixture with hydrochloric acid. The insoluble phthalylhydrazide is filtered off, leaving the amine hydrochloride in solution from which the amine may be liberated and isolated in the appropriate manner. 

The phthalimidoalkylsulfanylcarboxylic acid 592 was easily available from the corresponding chloro-iV-(pro-pyl)phthalimide 589 and methyl mercaptopropionate ester 590 and subsequent hydrolysis of ester 591 were obtained. Under standard irradiation conditions at 300 nm in acetone/water, the potassium salt of 592 cyclized with concomitant extrusion of C02 to give the isoindolothiazocine 561 in low yield (15 %) (Scheme 117). 

Another example of ring enlargement is provided by the aminomethylation of the potassium salt of N-hydroxy-phthalimide (Fig. 70), whieh affords the Mannich base 198 of dihydro-benzoxazine-dione, instead of the O-Mannich base of N-hydroxy-phthalimide, as previously proposed. -... 

The benzenedisulfonic acids are of little interest, except that benzene-1,3-disulfonic acid is a source of 1,3-dihydroxybenzene (see Chapter 4). The benzene dicarboxylic acids are more important. Benzene-1,2-dicarboxylic acid (phthalic acid, 8) can be converted into phthalic anhydride (9), which is a typical acid anhydride, reacting with amines and alcohols and also taking part in Friedel-Crafts reactions. Phthalimide (10), produced by reaction of the anhydride with ammonia, is weakly acidic and forms a potassium salt with ethanolic potassium hydroxide. 

The Gabriel method of making primary amines (Scheme 2.33) rests on the fact that the imide hydrogen of phthalimide is rendered acidic by the two carbonyl groups. It therefore forms a potassium salt, which is a powerful nucleophile and may be alkylated. Hydrolysis of the amide generates the primary amine. The cleavage of the phthalimide may be carried out with hydrazine (H NNHj). 

The reaction is accomplished by simply heating together phthalic anhydride and ammonium carbonate. Phthalimide then hydrolyzes with potassium hydroxide yielding the potassium salt of phthalamidic acid and this acid amide compound undergoes the Hofmann reaction (pp. 148, 685) with bromine (or chlorine) and potassium hydroxide by which one of the carboxyl groups is replaced by the amino group yielding amino benzoic acid or anthranilic acid. 

Potassium phthalimide (phthalimide K salt) [1074-82-4] M 185.2, m >300 . The solid may contain phthalimide and K2CO3 from hydrolysis. If too much hydrolysis has occurred (this can be clv rlfpd by... 

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