4-(Chlorosulfonyl)benzoic acid → Benzoic Acid

Participants

Reaction Steps

To a solution of N-(9-Amino-1,2-dihydro-1-oxobenzo[f]quinazolin-3-yl)pivalamide (1.38 g, 4.5 mmoles) in dry pyridine (10 ml) was added 4-(chlorosulfonyl)benzoic acid (5.0 g, 22.6 mmoles) at room temperature under a nitrogen atmosphere. After stirring for 3 days, the pyridine was removed under reduced pressure to leave a gummy brown residue which was suspended in water (30 ml), filtered, washed with water and dried to give 4-((N-(1,2-dihydro-1-oxobenzo[f]quinazolin-3- yl)pivalamide)-9-yl)amino)sulfonyl)benzoic acid (1.65 g). The foregoing material was dissolved in anhydrous 5% HCl/methanol (30 ml) and heated to 500 C with stirring under a nitrogen atmosphere for 27 hrs. Upon cooling, a fine precipitate formed which was then filtered, washed with methanol and dried to give methyl 4-(((3-Amino- 1,2-dihydro-1-oxobenzo[f]quinazolin-9-yl)amino)sulfonyl)benzoate as an off-white solid. (0.41 g, 27%) 1HNMR(DMSO-d51 200MHz) δ: 3.82(s, 3H, OCH3); 7.36(dd, J=8.8, 2.Hz, 1H, Ar); 7.39(d, J=8.8 Hz, 1H, Ar); 7.90(d, J=8.8 Hz, 1H, Ar); 7.98-8.11(m, 6H, Ar); 8.17(d, J=9.1 Hz, 1H, Ar); 9.33(d, J=2 Hz, 1H, Ar); 11.00(br s, 1H, NH). Anal. Calculated for C20H16N4 05S.3/5CH3 0H: C, 51.53; H, 4.07; Cl, 7.38; N, 11.67; S, 6.68. Found: C, 51.28; H, 3.80; Cl, 7.65; N, 11.90; S, 6.75.

Provenance & Evidence