From the mother liquors of the alkaloids described previously [1-3] we have obtained an optically inactive amorphous base with mp 69-70°C (petroleum ether), mol. wt. 228 (mass spectrometrically); picrate with mp 176°C, perchlorate with mp 166-167°C, nitrate with mp 155-157°C. UV spectrum: 218, 224 (inflection), 292 nm (log ε 4.13, 4.09, 3.88). The IR spectrum has the intense band of a carbonyl group at 1710 cm⁻¹ and also bands at 1490, 1593, and 1628 cm⁻¹ which are characteristic for quinazoline bases [4]. The presence of a carbonyl group was confirmed by the preparation of the oxime with mp 177-179°C. In the mass spectrum of the alkaloid, like those of deoxypeganine and peganol [1,3], the strongest peak is that of the ion with m/e 171, and ions with m/e 143, 116, and 89 are also recorded. In the mass spectra of peganine and peganidine [2], the maximum peak is that of the ion with m/e 187. Consequently, the alkaloid is based on a 2,3-trimethylene-3,4-dihydroquinazoline system. The results of a comparison of the IR, mass, and NMR spectra of the base isolated with those of peganidine permitted the conclusion that the alkaloid differs from the latter by the absence of a hydroxy group. The base is a new one and we have called it deoxypeganidine.