Benzaldehyde → HCID 54221010, compound

Participants

Reaction Steps

6-nitro-1,2,3,9-tetrahydro-pyrrolo[2,1-b]quinazoline-9-one, m.p. 196°-197° C. (3.7 g), prepared according to the Example 2, was reacted with benzaldehyde (2 g) in methanol (100 ml) in the presence of sodium methoxide (1.74 g) under stirring at room temperature for 16 hours and then at 60° C. for 4 hours. After concentration in vacuo of the suspension, the precipitate was filtered and washed with water until neutral: crystallization from CH2Cl2 -methanol gave 3-benzylidene-6-nitro-1,2,3,9-tetrahydro-pyrrolo[2,1-b]quinazoline-9-one, m.p. 255°-257° C. (3.5 g), which was reacted with SnCl2.2H2O (25 g) in 37% HCl (15 ml) and acetic acid (45 ml) under stirring at 60° C. for 3 hours. After cooling the precipitate was filtered and washed with water and then suspended under stirring in 2.5% aqueous NaHCO3 : the product was filtered, washed with water until neutral and then crystallized from ethanol to give 1.6 g of 6-amino-3-benzylidene-1,2,3,9-tetrahydro-pyrrolo[2,1-b]quinazoline-9-one, m.p. 268°-270° C., NMR (DMSO-d6) δppm: 3.23 (bt) (2H, C-2 protons), 4.11 (t) (2H, C-1 protons), 6.07 (bs) (2H, --NH2), 6.73 (m), (2H, C-5 and C-7 protons), 7.33-7.76 (m) (5H, phenyl protons), 7.68 (bs) (1H, =CH--), 7.83 (d) (1H, C-8 proton).

Provenance & Evidence