Synthesis and FT-IR Study of Some N-Monosubstituted 2,2-Dimethylpropanamides

Abstract

In our study of behaviour of the amide bond we investigated the conformations of some N-monasubstituted 2,2-dimethy|propanamides of the general formula CH3C(CH3)2CONHR, wherein R ranges from n-alkyl (C1-C7), iso-alkyil (C3-C6), sec-butyl, allyl, cycloalkyl (C3-C6), phenyl, to 4-substituted phenyl (where the substituents are fluoro, methyl, cyano, bromo, nitro, carboxymethyl, N,N-dimethylamino, methoxy, trifluoromethyl), 2-phenylethyl, and acetophenyl. The amides were synthesized by the well-known Schotten-Baumann reaction - the acylation of the corresponding amines with 2,2-dimethylpropionyl chloride. On the basis of FT-IR data for diluted solutions (concentrations lower than 10-3 mol dm-3) of the N-monosubstituted 2,2-dimethylpropanamides in carbon tetrachloride and dichloromethane, the exact position of the N-H stretching bands was established. The conformations and structures of N-monosubstituted 2,2-dimethy/propanamides were exactly proven on the basis of spectroscopic data. These results are in good accordance with 'H NMR and MS data.

U našem proučavanju amidne veze istraživali smo konformacije nekih N-monosupstituisanih 2,2-dimetilpropanamida opšte

formule CH3C(CH3)2CONHR, u kojima se VR mijenja od n-alkil (C1-C7), izo-alkil (C3-C6), sec-butil, alil, cikloalkil (C3-C6), fenil, do

4-supstituisanog fenila, (goje su supstituenti fenoro, metil, cijano, bromo, nitro, karboksimetil, N,N-dimetilamino, metoksi, trilluorometil)

2-feniletil acetofenil. Amidi su sintetizovani dobro poznatom Schotten-Baumanovom reakcijom - acilovanjem odgovarajućeg amina sa

2,2-dimetil propionil hloridom. Na bazi FT-IR podataka za razblazene rastvore (koncentracije nize od N-monosupstituisanih 2,2-dimetilpropanamida u CCI4 i CH2Cl2, ustanovijen je tačan položaj N-H stretching vipca. Konformacije i

strukture N-monosupstituisanih 2,2-dimetilpropanamida su egzaktno dokazane na bazi spektroskopskih podataka. Rezultati se dobro

slažu sa 'H NMR I MS podacima.