New domino-reaction for the synthesis of N⁴-(5-aryl-1,3-oxathiol-2-yliden)-2-phenylquinazolin-4-amines and 4-[4-aryl-5-(2-phenylquinazolin-4-yl)-1,3-thiazol-2-yl]morpholine

The model morpholine-1-carbothioic acid (2-phenyl-3H-quinazolin-4-ylidene) amide (1) reacts with phenacyl bromides to afford N⁴-(5-aryl-1,3-oxathiol-2-yliden)-2-phenylquinazolin-4-amines (4) or N⁴-(4,5-diphenyl-1,3-oxathiol-2-yliden)-2-phenyl-4-aminoquinazoline (5) by a thermodynamically controlled reversible reaction favoring the enolate intermediate, while the 4-[4-aryl-5-(2-phenylquinazolin-4-yl)-1,3-thiazol-2-yl]morpholine (8) was produced by a kinetically controlled reaction favoring the C-anion intermediate. ¹H nmr, ¹³C nmr, ir, mass spectroscopy and x-ray identified compounds (4), (5) and (8).