Carbonyldiimidazole with diamines

Photosensitive functions are in many cases also heat sensitive, so the preparation of photosensitive polyimides needs smooth conditions for the condensations and imidization reactions. Some chemical reactants, which can be used for polyamide preparation, have been patented for the synthesis of polyimides and polyimide precursors. For example, chemical imidization takes place at room temperature by using phosphonic derivative of a thiabenzothiazoline.102 A mixture of N -hydroxybenzotriazole and dicyclohexylcarbodiimide allows the room temperature condensation of diacid di(photosensitive) ester with a diamine.103 Dimethyl-2-chloro-imidazolinium chloride (Fig. 5.25) has been patented for the cyclization of a maleamic acid in toluene at 90°C.104 The chemistry of imidazolide has been recently investigated for the synthesis of polyimide precursor.105 As shown in Fig. 5.26, a secondary amine reacts with a dianhydride giving meta- and para-diamide diacid. The carbonyldiimidazole... 

Treatment of a chiral amine with phosgene is the cheapest way to prepare symmetrical ureas [29]. Nevertheless, due to the toxicity and reactivity of that reagent, it can advantageously be replaced by triphosgene [30] or l,l -carbonyldiimidazole [31-34] or other derivatives such as l,l -carbonyldi-2(lH)-pyridinone [35]. This procedure can be extended to thiophosgene (Scheme 1) and its thio-analogues, such as l,l -thiocarbonyldi-2(lH)-pyridinone to produce thioureas [36] chiral diamines can thus be transformed into the corresponding monoureas or monothioureas. 

Potassium cyanate, carbonic and chlorocarbonic esters, phosgene, or urea are used as cyclizing agents in the synthesis of perimidine-2-one 430 (X = X = NR, Y = O) and its derivatives from 1,8-naphthylene-diamines. Naphtho[substituted amino group in position 2 (X = Y = NH or Y = NR) are obtained on interaction of 1,8-naphthylenediamines with bromocyanogen, cyanoamide, 5-methylisothiourea, arylisothiocyanates, or dimethyltri-chloromethylamine. 

Wang (benzyloxybenzyl-OH) polystyrene resin was swollen in CH2CI2 and treated with carbonyldiimidazole (GDI) (4 equiv.) for 2 h. After filtration, the resin was washed with CH2CI2 (twice), DMF (three times), CH2CI2 (twice), and NMP (twice). Activated resin 45 was then heated for 4 h at 60 °C with a concentrated solution of the appropriate symmetrical diamine (4 equiv.) in NMP. After filtration, the resin was washed with NMP (twice), DMF (three times), CH2CI2 (twice), and MeOH (twice), and then dried in vacuo to provide 46. 

Another example of using carbonyldiimidazole derivatives for cyclization was reported by Houghten and coworkers (Scheme 9.30)." ° Starting with Boc-amino acid loaded MBHA resin 242 and after deprotection with TEA in DCM and neutralization with DIEA, 4-fluoro-3-nitrobenzoic acid 243 was attached to the resin-bound amino acid, giving resin 244. The fluoro group was substituted by different symmetrical diamines in DMF overnight to afford corresponding resin 245, the free amine of which reacted with Boc-amino acid 246 under... 

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