5-(diethylamino)pent-3-yn-2-ol

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: To a solution of 4.3 g α-oxo-2-thiopheneacetic acid in dichloromethane was added 0.5 ml pyridine, and 6.75 g thionyl chloride was then added dropwise under ice cooling. The mixture was heated under reflux for seven hours and concentrated under reduced pressure, diethyl ether was added to the residue, the insoluble matters were filtered off, and the filtrate was concentrated under reduced pressure. The oily substance thus obtained (4.1 g) was added dropwise to an etheral solution of 4.5 g 5-diethylamino-3-pentyn-2-ol under ice cooling, and the mixture was stirred for 18 hours under cooling with water and basified with an aqueous solution of potassium carbonate. The separated etheral layer was collected, washed with water, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The oily residue was purified by silica gel column chromatography (Wako Gel C-200; ethyl acetate), giving 2.48 g of the objective compound as oil. was then added dropwise under ice cooling The mixture was heated under reflux for seven hours concentrated under reduced pressure, diethyl ether was added to the residue the insoluble matters were filtered off the filtrate was concentrated under reduced pressure The oily substance thus obtained (4.1 g) The separated etheral layer was collected washed with water dried over anhydrous magnesium sulfate concentrated under reduced pressure The oily residue was purified by silica gel column chromatography (Wako Gel C-200; ethyl acetate)

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

Procedure: To a solution of 4.3 g α-oxo-2-thiopheneacetic acid in dichloromethane was added 0.5 ml pyridine, and 6.75 g thionyl chloride was then added dropwise under ice cooling. The mixture was heated under reflux for seven hours and concentrated under reduced pressure, diethyl ether was added to the residue, the insoluble matters were filtered off, and the filtrate was concentrated under reduced pressure. The oily substance thus obtained (4.1 g) was added dropwise to an etheral solution of 4.5 g 5-diethylamino-3-pentyn-2-ol under ice cooling, and the mixture was stirred for 18 hours under cooling with water and basified with an aqueous solution of potassium carbonate. The separated etheral layer was collected, washed with water, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The oily residue was purified by silica gel column chromatography (Wako Gel C-200; ethyl acetate), giving 2.48 g of the objective compound as oil. was then added dropwise under ice cooling The mixture was heated under reflux for seven hours concentrated under reduced pressure, diethyl ether was added to the residue the insoluble matters were filtered off the filtrate was concentrated under reduced pressure The oily substance thus obtained (4.1 g) The separated etheral layer was collected washed with water dried over anhydrous magnesium sulfate concentrated under reduced pressure The oily residue was purified by silica gel column chromatography (Wako Gel C-200; ethyl acetate)

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

Procedure: To a solution of 4.3 g α-oxo-2-thiopheneacetic acid in dichloromethane was added 0.5 ml pyridine, and 6.75 g thionyl chloride was then added dropwise under ice cooling. The mixture was heated under reflux for seven hours and concentrated under reduced pressure, diethyl ether was added to the residue, the insoluble matters were filtered off, and the filtrate was concentrated under reduced pressure. The oily substance thus obtained (4.1 g) was added dropwise to an etheral solution of 4.5 g 5-diethylamino-3-pentyn-2-ol under ice cooling, and the mixture was stirred for 18 hours under cooling with water and basified with an aqueous solution of potassium carbonate. The separated etheral layer was collected, washed with water, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The oily residue was purified by silica gel column chromatography (Wako Gel C-200; ethyl acetate), giving 2.48 g of the objective compound as oil. was then added dropwise under ice cooling The mixture was heated under reflux for seven hours concentrated under reduced pressure, diethyl ether was added to the residue the insoluble matters were filtered off the filtrate was concentrated under reduced pressure The oily substance thus obtained (4.1 g) The separated etheral layer was collected washed with water dried over anhydrous magnesium sulfate concentrated under reduced pressure The oily residue was purified by silica gel column chromatography (Wako Gel C-200; ethyl acetate)