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While nitrosation of 6-substituted 2, 4-dimethylpyrimidines with ethyl nitrite in liquid ammonia occurred preferentially at the 4-methyl group to give the corresponding pyrimidine-4-aldoximes, the same reaction of 1, 2, 4-trimethyl-6-oxo-1, 6-dihydropyrimidine (IV) afforded 1, 4-dimethyl-6-oxo-1, 6-dihydropyrimidine-2-aldoxime. Acylation of IV with ethyl benzoate and diethyl oxalate under basic conditions also gave α-(1, 4-dimethyl-6-oxo-1, 6-dihydro-2-pyrimidinyl) acetophenone and ethyl 3-(1, 4-dimethyl-6-oxo-1, 6-dihydro-2-pyrimidinyl) pyruvate, respectively.

Benzoylation of 2, 4-dimethyl-(Ia), 2, 4, 6-trimethyl-pyrimidine (Ib), 2, 4-dimethyl-quinazoline (Ic), 2, 4-dimethyl-(Id), 2, 4, 6-trimethyl-pyridine (Ie), and 2, 4-dimethyl-quinoline (If) with ethyl benzoate under basic conditions were performed. In analogy with the nitrosation with ethyl nitrite, methyl groups on the 4-position of IIa-f were preferentially benzoylated to give 4-phenacyl derivatives. Structures of all the products were determined by chemical derivatization.

The microwave spectrum of ethyl nitrite shows the presence of three rotational isomers. Two rotamers correspond to text-decoration:underlinecis, trans[τ1(ON—OC)= 0°, τ2(CC—ON)= 180°] and text-decoration:underlinecis, gauche(τ1= 0°, τ2= 80°) structures. Relative intensities show the text-decoration:underlinecis, gauche to be less stable by 238 ± 50 cm–1. A third rotamer, less stable than the text-decoration:underlinecis, trans by 81 ± 20 cm–1, has been assigned a text-decoration:underlinetrans, gauche structure (τ1= 180°, τ2= 90°). Internal rotation about the C—O bond in the text-decoration:underlinecis isomer has been studied through relative intensities of spectra in excited torsional states. For the text-decoration:underlinetrans isomer, a precise barrier height of 137 ± 7 cm–1 separating the two equivalent gauche forms has been derived from vibration–rotation interactions in the v= 1, C—O torsional state spectra of both text-decoration:underlinetrans, gauche CH3CH2ONO and CD3CD2ONO. Dipole moments for the three rotamers are also reported.