A formylstyrene-styrene-divinylbenzene resin. Synthesis,condensation reactions,and low-molecular-weight model compounds

A formylated resin ( 1a ) containing 4-formylphenyl groups was obtained from poly[styrene-co-divinylbenzene (2%)] by reaction with Cl₂CHOCH₃/SnCl₄ and subsequent hydrolysis of the intermediate. 1a reacted with N-methyltrimethylenediamine with the formation of azomethine groups. From the nitrogen content of the product the degree of functionalization of 1a was calculated to be 50%. Condensation reactions between 1a and N-ethylethylenediamine, cystamine, methanol, 1,2-ethanedithiol, 2,3-dimercapto-1-propanol (BAL), and 2-aminobenzene-thiol were also studied. A new chloromethylated resin was prepared from 1a and BAL in the presence of conc. hydrochloric acid (OH/Cl exchange). The formylation of 2,4-diphenylpentane yielded the low-molecular-weight model compounds 4-(1-methyl-3-phenylbutyl)benzaldehyde ( 2a ) and 2-(1-methyl-3-phenylbutyl)benzaldehyde ( 2b ) in an 87:13 mole ratio, suggesting that ca. 90% of the aldehyde groups in 1a are in para-position.