“…The precipitate formed was collected by filtration and washed with hot water. Recrystallisation from methanol led to the analytically pure products 7b -d; their 1 H and 13 C nmr spectral data are listed in Tables 2 and 3, respectively. 8-(4-Chlorophenyl)-6-phenyl-9H-pyrimido [4,5-b] [1,4] The general procedures for the preparation of the 6-amino-1,3dimethyl-5-(3-oxo-1,3-diaryl-1-propenylamino)-1,2,3,4-tetrahydropyrimidine-2,4-diones 8a, c, f, the respective 6,8-diaryl-2,3,4,7tetrahydro-1,3-dimethyl-1H-pyrimido [4,5-b] [1,4]diazepine-2,4diones 9a, c, f and their mass spectra are described in the literature [2]. The 1 H nmr spectra of 9a, c, f are listed in Table 2.…”