Urea → 5,6-Dihydrobenzo[h]quinazolin-2-ol

Participants

Reaction Steps

A mixture of alpha-tetralone (60 g, 0.41 M), urea (27 g, 0.45 M), triethylorthoformate (68 ml, 0.41 M), in methanol (80 ml) to which was then added methanesulfonic acid (100 drops) was heated at 100° C. for 30 min. then at 130° C. for 1 hr while allowing some solvent to distill off. The resulting thick suspension was cooled slurried with acetone (100 ml) and the solids isolated via filtration washing with acetone (2×80 ml). The solid was dried under reduced pressure overnight to afford 1 as a yellow solid (42.1 g as a 1:1 urea complex, 35.6% yield).

Provenance & Evidence