Competition between cyclisation and bisimine formation in the reaction of 1,3-diaminopropanes with aromatic aldehydes

摘要: Condensation of 1,3-diamines with aldehydes or ketones gives rise to two major products, the hexahydropyrimidine and bisimine. Experimental studies reaction between a range aromatic 1,3-diaminopropane 1,3-diamino-2-propanol establish that is favoured by less nucleophilic amine presence electron withdrawing groups on aryl ring aldehyde. Calculations indicate electronic nature this substituent influences both relative thermodynamic stability final products reactivity aldehyde as an electrophile.