2,3-dichlorocyclohexa-2,5-diene-1,4-dione

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1,4-Benzoquinone (2.01 g, 18.59 mmol) was dissolved in dry ether (50 mL) and dry chloroform (20 mL). The flask was placed under a constant flow of nitrogen and sulfuryl dichloride (5.02 g, 37.2 mmol) added dropwise over 15 minutes at 0° C. After 30 minutes the mixture was warmed to room temperature, stirred for another 30 minutes, returned to the ice-bath and treated with Et2O (25 mL) and conc. H2SO4 (30 mL). After 45 minutes the mixture was poured onto ice-water and extracted with further Et2O (3×75 mL). The combined organics were dried (MgSO4), filtered and concentrated to ca. 125 mL volume, whereupon silver oxide (9.96 g, 43 mmol) was added and the mixture stirred in the abscence of light for 1 hour. The mixture was filtered through celite, washing with ether and chloroform. Evaporation of the filtrate afforded an orange/yellow solid. The mixture was purified by flash chromatography, loading onto silica, eluting with a gradient of 0 to 20% EtOAc/Iso-Hexanes, holding at 9%, then re-purified by flash chromatography, loading onto silica, eluting with a gradient of 5 to 60% EtOAc/Iso-Hexanes, holding at 35%. This afforded compound x (1.15 g, 34.9%) as a bright yellow powder. added dropwise over 15 minutes at 0° C After 45 minutes the mixture was poured onto ice-water extracted with further Et2O (3×75 mL) The combined organics were dried (MgSO4) filtered was added the mixture stirred in the abscence of light for 1 hour The mixture was filtered through celite washing with ether and chloroform Evaporation of the filtrate afforded an orange/yellow solid The mixture was purified by flash chromatography eluting with a gradient of 0 to 20% EtOAc/Iso-Hexanes re-purified by flash chromatography eluting with a gradient of 5 to 60% EtOAc/Iso-Hexanes

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 1,4-benzoquinone Q-4 (2.0 g, 18.52 mmol) in diethyl ether-chloroform (4:1, 90 mL) at 0° C. and under N2 atmosphere was added sulfuryl chloride (3.0 mL, 37.0 mmol) dropwise over a period of 30 min. The reaction mixture was poured onto crushed ice, and extracted with diethyl ether (3×100 mL). Silver (I) oxide (10 g, 43.15 mmol) was added to the combined diethyl ether layers and the mixture was stirred for 1 h. After filtration, the filtrate was concentrated in vacuo to obtain crude Q-6, which was purified by column chromatography (silica gel, 10% ethyl acetate-pet. ether) to afford compound Q-6 (2.3 g, 71%) as a pale yellow solid. TLC Rf=0.6 (petroleum ether-EtOAc, 9:1); MS (ES) m/z 176 (M−H)−. The reaction mixture was poured onto crushed ice extracted with diethyl ether (3×100 mL) After filtration the filtrate was concentrated in vacuo to obtain crude Q-6, which was purified by column chromatography (silica gel, 10% ethyl acetate-pet. ether) to afford compound Q-6 (2.3 g, 71%) as a pale yellow solid

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of acetonitrile oxide was prepared by passing chlorine (10.8 grams) over 30 minutes into a stirred suspension of acetaldoxime (9 grams) and sodium bicarbonate (25.2 grams) in water at 0° C was added 2,3-dichlorobenzoquinone (17.7 grams) portionwise over 15 minutes. The mixture was stirred at 0°-5° C for 2 hours and then extracted with methylene chloride. The dried extracts were evaporated to dryness under reduced pressure and the residue recrystallized from ethanol to give the desired product as yellow crystals having a melting point of 214°-215° C. over 30 minutes extracted with methylene chloride The dried extracts were evaporated to dryness under reduced pressure the residue recrystallized from ethanol

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2,3-Dichlorobenzoquinone (22 grams) was added portionwise to a stirred solution of diazomethane (14 grams) in ether (500 milliliters) maintained at a temperature below 15° C. A pale yellow solid separated out from the solution, and this was filtered off and dried to yield the desired product having a melting point of 176°-177° C. maintained at a temperature below 15° C A pale yellow solid separated out from the solution this was filtered off dried