Dimethylformamide → HCID 18703164, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of product (1e) (6.79 g), dimethylformamide (60 cc), 4-(2,2-dimethoxyethyl)-5,6-dioxo-3-thioxoperhydro-1,2,4-triazine (1.68 g) and N,N-diisopropylethylamine (1.25 cc) is heated at 60° C., under nitrogen, for 4 hours, whilst stirring. The mixture is diluted with ethyl acetate (250 cc), washed with water (3×125 cc) and a saturated solution of sodium chloride (2×125 cc), dried over sodium sulphate and filtered and the filtrate is concentrated to dryness at 20° C. under 20 mm Hg (2.7 kPa). The residue obtained after this treatment is chromatographed on a column of Merck silica gel (0.06-0.2) (125 g) (diameter of the column: 3 cm, height: 43 cm). Elution is carried out with a 50/50 (by volume) cyclohexane/ethyl acetate mixture (1.5 liters) and ethyl acetate (1 liter), 100 cc fractions being collected. Fractions 16 to 21 are concentrated to dryness at 25° C. under 20 mm Hg (2.7 kPa); this yields the E form of the syn isomer of 2-benzhydryloxycarbonyl-7-{2-[(2-t-butoxycarbonylprop-2-yl)-oxyimino]-2-(2-tritylaminothiazol-4-yl)-acetamido}-3-55 2-[4-(2,2-dimethyloxyethyl)-5,6-dioxo-1,4,5,6-tetrahydro-1,2,4-triazin-3-yl]-thiovinyl}-8-oxo-5-thia-1-azabicyclo-[4.2.0]-oct-2-ene-5-oxide (product 1f) (5.5 g) in the form of a hard brown foam.

Provenance & Evidence