Reaction Steps
Benzoyl chloride (0.10 ml, 0.86 mmol) was added to a solution of 3-(2-methoxy-5-(5-trifluoromethyl-1H-tetrazol-1-yl)phenyl)-1-oxa-7-azaspiro[4,5]dec-3-ene hydrochloride (Desc. 11; 0.33 g, 0.79 mmol) in pyridine (5 ml) at 0° C. The mixture was stirred at 0° C. for 11/2 hours, allowed to warm to room temperature and concentrated in vacuo. 1M Hydrochloric acid (50 ml) was added to the residue and the mixture extracted with dichloromethane (2×25 ml). The combined extracts were dried (MgSO4), concentrated and the residue purified by flash chromatography, eluting with 21/2% methanol in dichloromethane, to afford the title compound as a white foam (0.26 g, 68%), which was recrystallised from ethyl acetate/hexane, m.p. 154°-156° C.; (Found: C, 59.29; H, 4.45; N, 14.15, C24H33F3N5O3 requires C, 59.38; H, 4.57; N, 14.43%); δH (360MHz, DMSO-d6, 353K) 1.62 (1H, m), 1.75-1.85 (3H, m), 3.19 (1H, m), 3.39 (1H, br d, J 12Hz), 3.49 (1H, m), 3.80 (1H, m), 3.94 (3H, s, ArOCH3), 4.74 (1H, m, 2-CHaHB), 4.89 (1H, dd, J 12.6, 1.9Hz, 2--CHAHB), 6.52 (1H, br s, 4--CH=), 7.30 (1H, d, J 8.8Hz, 3'-H), 7.37 (5H, m, PhH), 7.55 (1H, d, J 2.6Hz, 6'-H), 7.63 (1H, dd, J 8.8, 2.6Hz, 4'-H); m/z (ES+) 486 ([M+H]+).
