Studies on the Pyrimidine and Related Compounds. XXXVI. Infrared Spectra of 1-(and 3)-Substituted 3, 4-dihydro-2(1H)-pyrimidinone Derivatives and Some Reactions of These Compounds

Abstract

The correlation was seen between the positions of NH groups and the NH stretching pattern in infrared spectra of 1-substituted tetrahydropyrimidine derivatives and 3-substituted compounds. The measurement of the infrared spectra of these compounds in Nujol mull is useful to assign their structures. Differences in the reactivities between 1-NH and 3-NH groups were recognized by several reactions. Addition of dihydropyran to I occurred at 3-NH and the Michaeltype addition reaction proceeded giving N-1-adducts and N-1, 3-di-adducts.