C([N:5]1[CH2:9][CH2:8][N:7]([CH2:10][C:11]2[CH:16]=[CH:15][C:14]([N+:17]([O-:19])=[O:18])=[CH:13][CH:12]=2)[S:6]1(=[O:21])=[O:20])(C)(C)C>ClCCl.FC(F)(F)C(O)=O>[N+:17]([C:14]1[CH:15]=[CH:16][C:11]([CH2:10][N:7]2[CH2:8][CH2:9][NH:5][S:6]2(=[O:21])=[O:20])=[CH:12][CH:13]=1)([O-:19])=[O:18]A solution of the product from Step 1 (1.5 g) in anhydrous dichloromethane (10 ml) and trifluoroacetic acid (10 ml) was allowed to stand at room temperature for 48 hours. Solvents were removed under vacuum and the remaining residue was azeotroped with methanol (1×25 ml) and crystallised from ethyl acetate-hexane to give 966 mg (78%) of the title compound as a pale yellow solid; mp 115°-117° C.; δH (250 MHz, CDCl3) 8.23 (2H, d, J=8.8 Hz, Ar--H), 7.57 (2H, d, J=8.8 Hz, Ar--H), 4.38 (1H, br t, --NH--), 4.29 (2H, s, Ar--CH2 --), 3.54 (2H, q, J=6.6 Hz, --CH2 --NH--), 3.34 (2H, t, J=6.6 Hz, --CH2 --).
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