Polystyrene aminomethyl

The submitters performed the reaction using a 0.12 mmol excess of Fmoc-L-Asp-Ot-Bu, under which conditions aminomethylated polystyrene resin was required to remove the excess carboxylic acid (Note 13). The checkers modified the reaction to use 0.28 mmol excess Disperse Red 1. The initial Amberlyst-15 filtration removes this material. 

To remove carboxylic acid, the crude product is redissolved in 20 mL of methylene chloride and is shaken for 30 min with 1 g of aminomethylated polystyrene resin with a substitution of 1.02 mmol/g, available from Novabiochem (Note 3). After filtration and washing of the resin with 50 mL of methylene chloride, the filtrates were collected together in a 250-mL flask and the solvent was removed on a rotary evaporator. 

Similarly, a solid-supported imide has been reported to serve as an acylating reagent under microwave conditions by Nicewonger and coworkers [130], The starting imide was immobilized on aminomethyl polystyrene and in this case benzoyl chloride was chosen to prepare the acylating reagent (Scheme 7.111). Primary amines and piperazines were smoothly acylated at room temperature, but more hindered secondary amines required more time and higher temperatures, and anilines... 

Zikos CC, Ferderigos NG (1995) Preparation of high capacity aminomethyl-polystyrene resin. Tetrahedron Lett 36 3741-3744... 

A number of amines have been investigated for their suitability as polymerisation initiators, including aliphatic amines (such as butylamine [17] and 1,3-diaminopropane [18]), polymer supported amines (such as cross-linked aminomethyl polystyrene [CLAMPS], Fig. 1, giving rise to immobilised polyamino acids [19]) and resin-bound amines. 

For the synthesis of perfectly dendronized sohd-phase polymers (Fig. 7.4) various dendritic structures were prepared based on amide connections [6]. For example, the naturally occurring amino acid lysine was used as a building block in creating a dendritic scaffold [33]. The synthesis of symmetrical tri-branching den-drimers on aminomethyl polystyrene macrobeads was also described in literature [34]. Recently, aryl ether dendrimers were prepared on hydroxymethyl polystyrene using a Mitsunobu reaction with 3,5-bis(acetoxymethyl)phenol [35]. 

Attachment of Compound 11 onto an Aminomethylated Polystyrene Resin 1 3141 A 1% cross-linked aminomethylated polystyrene resin (0.83 mmol of amino group per gram of resin, 2.41 g, 2 mmol) was placed in an ATC Model 90 reaction vessel (capacity 200 mL) and the resin washed successively with NMP, 10% DIPEA in NMP, and NMP. Then, 11 (1.41 g, 3 mmol, 1.5 equiv), HBTU (1.14 g, 3 mmol), and HOBt (0.41 g, 3 mmol) were dissolved in NMP (20 mL) in a flask, and DIPEA (0.78 mL, 4.5 mmol) was added to the soln immediately. The mixture was introduced into the reaction vessel containing the resin within 2 min after addition of DIPEA, and the entire mixture was agitated for lh at rt. The soln was drained from the reaction vessel and the resin washed well with NMP. The completion of the coupling reaction was confirmed by a ninhydrin test. 

Figure 3.8 Reagents and conditions (i) Dean-Stark then BrCHaCOaEt, K2CO3, dibenzo-18-crown-6, acetone, 95% (ii) SOCI2, DMF (cat.), 71% (iii) EtsN, CH2CI2, 55% (iv) (Boc)20, dipea, CH2CI2, 98 % (v) NaOH, H2O, 95 % (vi) aminomethylated polystyrene, DCC, pentafluorophenol, DMAP (vii) TEA, CH2CI2. Reprinted from reference [3], with permission from Elsevier.

A dry 50 mL Schlenk reaction tube was flushed with nitrogen and charged with a mixture of 7 (527mg, l.Ommol), 1,3-dicyclohexylcarbodiimide (1.04g, 5mmol), pentafluorophenol (920 mg, 5 mmol), 4-(dimethylamino)pyridine as the catalyst and the aminomethylated polystyrene (930 mg, 1.07 mmol g ) in dry dichloromethane (20 mL). The mixture was stirred at room temperature for 24h under a N2 atmosphere. The polymer was filtrated, rinsed sequentially with CH2CI2 and acetone and dried at 50 °C in vacuo to yield the polymer-bound ligand 8 as pale yellow beads. 

Aminomethylated polystyrene (DVB I %, 1.07 mmol Trifluoroacetic acid / dichloromethane (I/I, v/v), 10mL 3-Bromopropionic acid (97 %) (158 mg, I mmol) Cesium carbonate (99.9%) (652 mg, 2 mmol) Triethylamine Benzene Acetone... 

Fig. 9. 600 MHz EXSY spectrum showing the exchange of magnetization between ammonium protons and two distinct water components in a peptidyl-water cluster bound to -aminomethyl polystyrene resin swollen in DMF-d1. Reproduced with permission from Ref. 88. Copyright 2001 American Chemical Society.

Chloromethyl polystyrene (Merrifield resin) has been prepared by chloro-methylation of polystyrene [23,27,53,54], by copolymerization of 4-chloromethylsty-rene with styrene [20,26,55,56], and by chlorination of poly(4-methylstyrene) [57,58], Aminomethyl polystyrene is most conveniently prepared by direct amidomethylation of polystyrene with (hydroxymethyl)amides or (halomethyl)amides under acidic conditions followed by hydrolysis [59-62], but it has also been prepared directly from chloromethyl polystyrene ([63,64] see also Section 10.1.1.1). 

AM-resin BAL BEMP resin Aminomethylated polystyrene Backbone amide linker Resin 2-ferf-Butylimino-2-diethylamino-l,3-dimethyl-perhydro-1,3,2-diazaphosphorine immobilized on polystyrene resin... 

A library of di- and trisubstituted 5-amino-l 77-1-benzazepine derivatives was assembled through attachment of a preformed 1-benzazepine unit to an aminomethylated polystyrene resin. The initial solution phase synthesis of the 1-benzazepine moiety was based on an intramolecular Dieckmann cyclization (type d) followed by a ketone to primary amino group transformation via reduction ( NaBH3CN) of an imine intermediate <2007JC0487>. 

Fig. 1. Preparation of TFP resin from aminomethyl polystyrene and 4-hydroxy-2,3,5,6-tetrafluorobenzoic acid.

Procedure. A 2-liter three-necked flask fitted with an overhead stirrer and thermometer was charged with DMF (1 liter) and aminomethyl polystyrene resin (Polymer Labs). Freshly prepared solutions of TFP in DMF and HOBt in DMF were sequentially added followed by DIC. The reaction mixture was stirred at room temperature for 16 h and then filtered and washed well with DMF, THF, and DCM to give the TFP resin containing ca. 10% of the undesired TFP-tetrafluorobenzoic acid ester. 

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