Benzoic acid, 4-amino-, 1,1-dimethylethyl ester → tert-Butyl 4-[N-((6RS)-2-(2,2-dimethylpropionyloxymethyl)-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[g]quinazolin-6-yl)amino]benzoate

Participants

Reaction Steps

A suspension of 2-(2,2-dimethylpropionyloxymethyl)-3,4,7,8-tetrahydro-6H-cyclopenta[g]quinazolin-4,6-dione (0.47 g, 1.50 mmol) in anhydrous methanol (33 ml) and anhydrous CH2Cl2 (5 ml) was treated with tert-butyl 4-aminobenzoate (0.34 g, 1.78 mmol) followed by decaborane (0.07 g, 0.58 mmol) and the mixture stirred at room temperature under argon for 18 h. The solvent was removed in vacuo and the residue purified by column chromatography (50 g of silica gel) eluting with 30% ethyl acetate in CH2Cl2 to yield the desired product as a white solid (0.43 g, 58%); m.p. 231° C.; 1H-NMR (CDCl3) δ 1.26 (s, 9H, CMe3), 1.58 (s, 9H, CO2CMe3), 2.00 (m, 1H, 7-H), 2.72 (m, 1H, 7-H), 3.08 (m, 2H, 8-H), 5.10 (s, 2H, 2-CH2), 5.15 (m, 1H, 6-H), 6.67 (d, J=8.8 Hz, 2H, 3′-H, 5′-H), 7.58 (s, 1H, 9-H), 7.87 (d, J=8.8 Hz, 2H, 2′-H, 6′-H), 8.24 (s, 1H, 5-H); MS (FAB, m/z): Found 491 [(M+H)+, 25%], 514 [(M+Na)+, 100%]; Found C, 68.37; H, 6.86; N, 8.35. C28H33N3O5 requires C, 68.41; H, 6.77; N, 8.55%.

Provenance & Evidence