This reaction mixture (which contains the free base of the compound of StepA) was added stepwise to an ice cooled, stirred suspension of 1.02 g of 50%dispersion of sodium hydride. The resulting mixture is stirred 30 min. on an ice-water bath. To this cold suspension (which contains the alkoxide ofthe compound of Step A) there was added a solution of benzyl chloride (2.48g) in DMF. The resultant mixture was stirred in an ice bath for 5 min., at room temperature for 5 min., and then in a heating bath at 85°-90° C. for 1.5 hrs. The solvent was evaporated off at reduced pressure. To the residue there was added water and the mixture wasextracted three times with a 1:1 mixture of methylenechloride and ether. The combined extracts were washed with brine, dried over Na2SO4and the solvent evaporated at reduced pressure. The oily residue was chromatographed on silica gel, using a 1:1 mixture of acetone and methylene chloride as eluant. The title compound was obtained as a yellow oil with the following PMR spectrum (DMSO-d6): 2.08(3H,s); 1.7-2.2(4H,m); 3.65-4.1(2H,m); 4.42(IH, deformed triplet); 4.70(2H,s); 6.73(IH,s); 7.30(SH,s).
