sodium;ethyl carbonate

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

Procedure: The organic pyrocarbonates may be prepared by reacting alkali metal organic carbonate, e.g., sodium ethyl carbonate, with organic halocarbonate, e.g., ethyl chlorocarbonate (ethyl chloroformate). The organo groups of the organic carbonate and halocarbonate are chosen to correspond to the organo groups desired for the pyrocarbonate. For example, sodium ethoxide, which can be prepared by dissolving sodium metal in a toluene solution of ethyl alcohol, is carbonated with carbon dioxide to prepare sodium ethyl carbonate. Thereafter, the sodium ethyl carbonate is reacted with ethyl chloroformate to form diethyl pyrocarbonate and sodium chloride. The chloride salt is filtered and the pyrocarbonate recovered by distillation.

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

Procedure: The dialkyl pyrocarbonates may be prepared by reacting alkali metal alkyl carbonate, e.g., sodium ethyl carbonate, with alkyl halocarbonate, e.g., ethyl chlorocarbonate (ethyl chloroformate). The alkyl groups of the alkyl carbonate and halocarbonate are chosen to correspond to the alkyl group desired for the pyrocarbonate. For example, sodium ethoxide, which can be prepared by dissolving sodium metal in toluene solution of ethyl alcohol, is carbonated with carbon dioxide to prepare sodium ethyl carbonate. Thereafter, the sodium ethyl carbonate is reacted with ethyl chloroformate to form diethyl pyrocarbonate and sodium chloride. The chloride salt is filtered and the pyrocarbonate recovered by distillation.

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

Procedure: The organic pyrocarbonates may be prepared by reacting alkali metal organic carbonate, e.g., sodium ethyl carbonate, with organic halocarbonate, e.g., ethyl chlorocarbonate (ethyl chloroformate). The organo groups of the organic carbonate and halocarbonate are chosen to correspond to the organo groups desired for the pyrocarbonate. For example, sodium ethoxide, which can be prepared by dissolving sodium metal in a toluene solution of ethyl alcohol, is carbonated with carbon dioxide to prepare sodium ethyl carbonate. Thereafter, the sodium ethyl carbonate is reacted with ethyl chloroformate to form diethyl pyrocarbonate and sodium chloride. The chloride salt is filtered and the pyrocarbonate recovered by distillation.

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

Procedure: The organic pyrocarbonates may be prepared by reacting alkali metal organic carbonate, e.g., sodium ethyl carbonate, with organic halocarbonate, e.g., ethyl chlorocarbonate (ethyl chloroformate). The organo groups of the organic carbonate and halocarbonate are chosen to correspond to the organo groups desired for the pyrocarbonate. For example, sodium ethoxide, which can be prepared by dissolving sodium metal in a toluene solution of ethyl alcohol, is carbonated with carbon dioxide to prepare sodium ethyl carbonate. Thereafter, the sodium ethyl carbonate is reacted with ethyl chloroformate to form diethyl pyrocarbonate and sodium chloride. The chloride salt is filtered and the pyrocarbonate recovered by distillation.

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

Procedure: To a solution of 1-chloroethyl 5-(2,4-difluorophenyl)salicylate (5.0 g) in about 40 ml of DMF is added portionwise 3.0 g of sodium ethyl carbonate. The reaction is stirred at room temperature and then concentrated in vacuo. The concentrate is partitioned between ether/ethyl acetate and acidified water. The organic layer is separated and the aqueous layer is again extracted with ether, the organic layers are pooled and washed with water followed by drying and concentration to the crude product. After further purification by chromatography as described in Example 1, the product is crystallized from hexane to afford pure 1-(ethoxycarbonyloxy)ethyl 5-(2,4-difluorophenyl)salicylate. concentrated in vacuo The concentrate is partitioned between ether/ethyl acetate The organic layer is separated the aqueous layer is again extracted with ether washed with water by drying concentration to the crude product After further purification by chromatography the product is crystallized from hexane

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

Procedure: The organic pyrocarbonates may be prepared by reacting alkali metal organic carbonate, e.g., sodium ethyl carbonate, with organic halocarbonate, e.g., ethyl chlorocarbonate (ethyl chloroformate). The organo groups of the organic carbonate and halocarbonate are chosen to correspond to the organo groups desired for the pyrocarbonate. For example, sodium ethoxide, which can be prepared by dissolving sodium metal in a toluene solution of ethyl alcohol, is carbonated with carbon dioxide to prepare sodium ethyl carbonate. Thereafter, the sodium ethyl carbonate is reacted with ethyl chloroformate to form diethyl pyrocarbonate and sodium chloride. The chloride salt is filtered and the pyrocarbonate recovered by distillation.

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

Procedure: The dialkyl pyrocarbonates may be prepared by reacting alkali metal alkyl carbonate, e.g., sodium ethyl carbonate, with alkyl halocarbonate, e.g., ethyl chlorocarbonate (ethyl chloroformate). The alkyl groups of the alkyl carbonate and halocarbonate are chosen to correspond to the alkyl group desired for the pyrocarbonate. For example, sodium ethoxide, which can be prepared by dissolving sodium metal in toluene solution of ethyl alcohol, is carbonated with carbon dioxide to prepare sodium ethyl carbonate. Thereafter, the sodium ethyl carbonate is reacted with ethyl chloroformate to form diethyl pyrocarbonate and sodium chloride. The chloride salt is filtered and the pyrocarbonate recovered by distillation.