C(Cl)(=O)C(Cl)=O.CS(C)=O.[OH:11][CH2:12][C:13]1[CH:20]=[CH:19][C:16]([C:17]#[N:18])=[CH:15][N:14]=1.C(N(CC)CC)C>ClCCl>[CH:12]([C:13]1[CH:20]=[CH:19][C:16]([C:17]#[N:18])=[CH:15][N:14]=1)=[O:11]Oxalyl chloride (936 mg, 7.38 mmol) is dissolved in dichlormethane (8 ml) under an argon atmosphere and cooled to −78° C. in an acetone dry-ice bath. Dimethylsulfoxide (1.153 g, 14.76 mmol) is added dropwise and the mixture is stirred for 20 minutes at −78° C. The compound of Example 32A (900 mg, 6.71 mmol) is added dropwise as a dichloromethane (7 ml) solution. The reaction is stirred for an additional two hours at −78° C. Triethylamine (3.05 g, 30.19 mmol) is added and the reaction is kept at −78° C. for 10 minutes, then allowed to warm to room temperature. The reaction is quenched with saturated ammonium chloride solution and extracted with ethyl acetate. The ethyl acetate phase is washed with bicarbonate and brine, dried over magnesium sulphate monohydrate, filtered and concentrated to afford a yellow oil. The crude oil is purified by column chromatography on silica gel with dichloromethane as eluent.
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