tert-Butylsulphinamide (3.0, 24 mmol) followed by titanium (IV) ethoxide (4.6 ml, 36 mmol) was added to a stirring solution of the product of Step 3 (4.56 g, 11 mmol) in dry THF (10 ml) and the resulting solution was heated to reflux for 18 hrs. The reaction was poured into a stirring solution of brine (200 ml) and then ethyl acetate (100 ml) was added and the mixture filtered through celite. The filtrate was partitioned and the aqueous layer was further extracted with ethyl acetate (2×50 ml). The combined organic extract was washed with brine, dried over MgSO4 and concentrated in vacuo, to afford N((9Z)-3-chloro-4-{(E)-2-[5-(4-fluorophenyl)-1-methyl-1H-pyrazol-3-yl]vinyl}bicyclo[4.2.1]non-3-en-9-ylidene)-2-methylpropane-2-sulfinamide (5.19 g, 99%). m/z (ES+) 474 (MH)+. Compound taken directly onto next Step.
