4-(4-Benzyloxy-benzenesulfonyl)-1-benzyl-piperidine-4-carboxylic acid ethyl ester (5.0 g, 10.1 mmol) was dissolved in MeOH/THF (1:1, 200 ml) and stirred at room temperature for 72 hrs. At the end reaction mixture was concentrated and the product was nuetralised with con. HCl by dissolving it in water (200 mL). After the neutralization reaction mixture was concentrated to dryness. Ice cold water (100 mL) was added to the solid and filtered. The product 4-(4-Benzyloxy-benzenesulfonyl)-1-benzyl-piperidine-4-carboxylic acid was dried at 50° C. and taken to next step with out any purification. Colorless solid. MP: 66-68; Yield: 4.3 g, 91% ; MS: 466 (M+H) Starting from 4-(4-Benzyloxy-benzenesulfonyl)-1-benzyl-piperidine-4-carboxylic acid (4.65 g, 10.0 mmol) and following the procedure outlined in example 83, 1.1 g of 4-(4-Benzyloxy-benzenesulfonyl-1-benzyl-piperidine-4-carboxylic acid hydroxyamide was isolated as a colurless solid. Yield 21%; mp 89° C.; MS: 481.1 1H NMR (300 MHz, DMSO-d6): δ2.27 (m, 3H), 2.76-2.79 (m, 2H), 3.43 (m, 4H),4.30 (s, 2H), 7.14-7.17 (d,2H), 7.50-7.73 (m, 5H), 9.37 (s, 1H), 10.53 (s, 1H), 11.18 (s, 1H).
