Ethanol → HCID 15280848, compound

Participants

Reaction Conditions

Reaction Steps

(1S, 2R, 3R, 5R)-3-(Acetoxymethyl)-5-(5,6-dichloro-1H-benzimidazol-1-yl)-1,2-cyclopentanediyl diacetate (2.00 g, 4.51 mmol) was dissolved in dry N,N-dimethylformamide (9 mL) and heated to 90° C. N-bromosuccinimide (1.62 g, 9.02 mmol) was added in four portions over 5 hours.. Volatiles were evaporated in vacuo. The residue was chromatographed on silica gel and product was eluted with 30-50% ethyl acetate-hexanes as a yellow glass (1.00 g, 43%); 1H-NMR(DMSO-d6) consistent with structure. This sample was deblocked with sodium carbonate (203 mg, 1.9 mmol) in water (3 mL)-ethanol(15 mL)-methanol(15 mL) at ambient temperature for 5 hours. The pH was adjusted to 7 with acetic acid. The solution was evaporated to dryness in vacuo and the residue was triturated with water to give white powder which was chromatographed. Elution of a silica gel column with 10-12% methanol-chloroform gave (1S, 2R, 3R, 5R)-5-(2-bromo-5,6-dichloro-1H-benzimidazol-1-yl)-3-(hydroxymethyl)-1,2-cyclopentanediol as white powder after solidification from 1:1 ethanol-methanol (410 mg, 54%), m.p. 212°-215° C.; 1H-NMR(DMSO-d6) and mass spectrum identical with those of racemate described in Example 4; [α]20589 -31.2°, [α]20578 -32.3°, [α]20546 -37.3° (c=0.260, methanol).

Provenance & Evidence