Phthalimides —

The polyimides from these dianhydrides and various diamines were synthesized by the two-step procedure in NMP, and the polyimides were obtained by thermal imidation (100°C/1 h, 200°C/1 h, 300°C/1 h) (Eq. 7). The properties of pol)rimides from 4,4 -ODA and PDA were compared with those of polpmides from s-BPDA (m = 0) and 3,3 ,4,4 -p-terphenyl tetracarboxylic dianhydride (m = 1) (Table 7.6). 

The CTE values of PI-m-PDAs were lower than those of Pl-m-4,4 -ODA, because of their rigid linear structures. This rigid linear structure is thought to be indispensable for the polyimides with low CTE [51,52], and the CTE values decreased with increasing m in these polyimides (PI-m-4,4 -ODAand PI-m-PDA). However, the CTE values for polyimides have been reported to be dependent on the method for film preparation [53,54]. For example, partially 

Almost aU the polyimides from other diamines showed similar thermal properties. The Tg values were hardly dependent on m (Table 77). The decrements in E at Tg decreases with increasing m, and E s above the Tg increase on curing above Tg. The valves of the above the Tg for the polyimides were in order of PI-2-Ar PI-3-Ar PI Ar. 

The CTE values of PI-m-3ether were not higher than those of PI-m-4,4 -ODA due to the more flexible rotational ether linkages, but the values decreased with increasing m. The values were drastically lowered by annealing, and crystallization had a great influence on CTE. 

The extent of water absorption is about 2.5% for Kapton-type poly-imide, and 0.4% for poly (ethylene terephthalate). As the ester 

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It is prepared by the action of sodium hydroxide and sodium hypochlorite on phthalimide (Hofmann reaction). When heated with soda lime it gives aniline. 

They are formed by heating dibasic acids or their anhydrides with ammonia. The hydrogen atom of the NH group is acidic and can be replaced by a metal. Mild hydrolysis breaks the ring to give the half amide of the acid. See succinimide and phthalimide. 

Prepared by stirring phthalimide with cold concentrated ammonia solution. Hydrolysed to phlhalic acid with dilute acids. Dehydration with ethanoic anhydride gives first n-cyano-benzamide and then phthalonitrile. 

Treatment with PCI5 gives phthalyl chloride reduction with zinc and ethanoic acid or NaOH gives phthalide. Fusion with urea gives phthalimide. 

When treated with alkaline hypochlorite solution anthranilic acid is obtained. This reaction, the first stage in the indigo synthesis, is the most important commercial outlet for phthalimide. 

Ammonium acetate CH3COONH4 Acetamide CH CONHj Acetonitrile CH CN Phthalimide C,H,(CO),NU Acetanilide C H,NHCOCH,... 

Phthalcin reaction. Fuse together very gently in a dry test-tube 01 g. of phthalimide, O l g. of phenol and 2 drops of cone. HjSO, Cool, add waier and then NaOH solution in excess. A red coloration is produced which is decolorised by acids. (Note. Succinimide gives no definite coloration in these circumstances.)... 

N-Substituted phthalimides. Phthalic anhydride reacts with primary amines only to yield N-substituted phthaUmides ... 

Benzylamine may be obtained by the Gabriel synthesis, which depends upon the use of potassium phthalimide. The latter upon heating with benzyl... 

The independent preparation of potassium phthabmide (from a solution of phthalimide in absolute ethanol and potassium hydroxide in 75 per cent, ethanol) may be avoided in many cases by boiling phthalimide with the halide in the presence of anhydrous potassium carbonate. The N-substituted phthalimide (I) is frequently cleav with difficulty this is often facilitated by reaction with hydrazine hydrate to give an intermediate product, which is easily decomposed by hydrochloric acid to 3deld the insoluble hydrazide of phthaUc acid (II) and the primary amine (III) ... 

Benzylatnine. Warm an alcoholic suspension of 118-5 g. of finely-powdered benzyl phthalimide with 25 g. of 100 per cent, hydrazine hydrate (CAUTION corrosive liquid) a white, gelatinous precipitate is produced rapidly. Decompose the latter (when its formation appears complete) by heating with excess of hydrochloric acid on a steam bath. Collect the phthalyl hydrazide which separates by suction filtration, and wash it with a little water. Concentrate the filtrate by distillation to remove alcohol, cool, filter from the small amount of precipitated phthalyl hydrazide, render alkaline with excess of sodium hydroxide solution, and extract the liberated benzylamine with ether. Dry the ethereal solution with potassium hydroxide pellets, remove the solvent (compare Fig. //, 13, 4) on a water bath and finally distil the residue. Collect the benzylamine at 185-187° the 3ueld is 50 g. 

P-Phenylethylamine. Prepare p-phenylethyl phthalimide as above by substituting P phenylethyl bromide (Section 111,37) for benzyl... 

Anthranilic acid. This substance, the ortho amino derivative of benzoic acid, may be conveniently prepared by the action of sodium hypobromite (or sodium hypochlorite) solution upon phthalimide in alkaline solution at 80°. The ring in phthalimide is opened by hydrolysis to phthalamidic acid and the latter undergoes the Hofmann reaction (compare Section 111,116) ... 

Phthalide. In a 1 litre bolt-head flask stir 90 g. of a high quality zinc powder to a thick paste with a solution of 0 5 g. of crystallised copper sulphate in 20 ml. of water (this serves to activate the zinc), and then add 165 ml. of 20 per cent, sodium hydroxide solution. Cool the flask in an ice bath to 5°, stir the contents mechanically, and add 73-5 g. of phthalimide in small portions at such a rate that the temperature does not rise above 8° (about 30 minutes are required for the addition). Continue the stirring for half an hour, dilute with 200 ml. of water, warm on a water bath imtil the evolution of ammonia ceases (about 3 hours), and concentrate to a volume of about 200 ml. by distillation vmder reduced pressure (tig. 11,37, 1). Filter, and render the flltrate acid to Congo red paper with concentrated hydrochloric acid (about 75 ml. are required). Much of the phthalide separates as an oil, but, in order to complete the lactonisation of the hydroxymethylbenzoic acid, boil for an hour transfer while hot to a beaker. The oil solidifles on cooling to a hard red-brown cake. Leave overnight in an ice chest or refrigerator, and than filter at the pump. The crude phthalide contains much sodium chloride. RecrystaUise it in 10 g. portions from 750 ml. of water use the mother liquor from the first crop for the recrystaUisation of the subsequent portion. Filter each portion while hot, cool in ice below 5°, filter and wash with small quantities of ice-cold water. Dry in the air upon filter paper. The yield of phthalide (transparent plates), m.p. 72-73°, is 47 g. 

Phthalonitrile may be prepared by the following series of reactions from phthalimide —... 

Phthalamide. Mix 200 g. of phthalimide (Section IV,169) with 600 ml. of concentrated ammonia solution in a 1 litre beaker and stir mechanically for 24 hours. Filter off the micro-crystalline cake of phthalamide and dry at 100°. The yield is 200 g., m.p. 220° (decomp.). 

Nitro compounds. Nitromethane Nitrobenzene ni-Dinitrobenzene. Amides and imides. Acetamide re-Caproamide Acetanilide Benz-anilide Phthalimide. 

Supplement 1953 3103-3241 Carbonyl compounds a-Pyrrolidone, 236. Tropinone, 259. Succinimide, 369. Isatin, 432. Phthalimide, 458. 

The carbonyiation of o-diiodobenzene with a primary amine affords the phthalimide 501 [355,356]. Carbonyiation of iodobenzene in the presence of (9-diaminobenzene (502) and DBU or 2,6-lutidine affords 2-phenylbenzimida-zole (503)[357, The carbonyiation of aryl iodides in the presence of pentaflnor-oaniline affords 2-arylbenzoxazoles directly, 2-Arylbenzoxazole is prepared indirectly by the carbonyiation of (9-aminophenol[358j. The optically active aryl or alkenyl oxazolinc 505 is prepared by the carbonyiation of the aryl or enol triflates in the presence of the opticaly active amino alcohol 504, followed by treatment with thionyl chloride[359]. 

Carbamates are allylated in the presenee of strong bases in DMSO or HMPA[197], Phthalimide (320) and succimide are allylated with the allyl-isoureu 321 at room temperature or the allylic acetate 322 at 100 C[I98.I99], Di-/-butyl iminodicarbonate is used as a nitrogen nucleophile[200]. 

Phthalimide has been piepaied in 95% yield by heating the com pound foimed on reaction of phthalic anhydiide (Section 20 5) with excess ammo nia This compound has the moleculai foimula C8H10N2O3 What is its stiuctuie ... 

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... 

Among compounds other than simple alkyl halides a halo ketones and a halo esters have been employed as substrates m the Gabriel synthesis Alkyl p toluenesul fonate esters have also been used Because phthalimide can undergo only a single alkyl ation the formation of secondary and tertiary amines does not occur and the Gabriel synthesis is a valuable procedure for the laboratory preparation of primary amines... 

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