6-Chloropropionaldehyde diethyl acetal

Chloropropionaldehyde diethyl acetal Pipoxolan HCI a-Chloropropionyl chloride Carticaine... 

Acetalization. /5-Chloropropionaldehyde diethyl acetal can be prepared from acrolein in 88% yield by reaction of ethanol in the presence of hydrogen chloride dissolved in ether and with a 4 A molecular sieve as water scavenger.2 In the absence of a molecular sieve the yield drops to 65%. If ethanolic hydrogen chloride is used the yield is 34%.3... 

Furan dicarboxylic acid, 6, was prepared by a five-step procedure. Cold acrolein was added slowly to a stirred solution of HCl-saturated absolute ethanol at about 0° to form 3-chloropropionaldehyde diethyl acetal,(6). 

Chloropropionaldehyde diethyl acetal, purified by fractional distillation under reduced pressure (12-20 torr), was refluxed for 24 hrs. with potassium cyanide and potassium iodide in a mixture of water and ethanol giving 4,4-diethoxybutyronitrile, in 59% yield.An attempt was also made to prepare the nitrile by treating 3-chloropropionaldehyde diethyl acetal with sodium cyanide in dimethyl sulfoxide at about 150° over the course of about one hour. After stirring overnight, the reaction solution... 

Chloropropionaldehyde Diethyl Acetal. According to the literature procedure,200 g of absolute ethanol was saturated with dry hydrogen chloride (bubbled through concentrated sulfuric acid) in a 500 ml, threenecked flask, in an ice-water bath. The ethanolic solution was then transferred to a 3-liter, 3-necked flask fitted with an inlet tube, a bubbler, and a magnetic stirrer. The flask was cooled in an ice-water bath. The three-necked flask was also fitted with an efficient condenser which was connected to an exhaust bubbler. To the cold, acidified ethanol was added 112 g (2 moles) of cold acrolein from the liquid addition flask over the course of 1-2 hrs. This solution was then quickly transferred to a 2-liter separatory funnel which was sealed and placed in a refrigerator. After approximately 15 minutes, two layers had separated. The lower layer of acetal was collected and neutralized by the slow addition of powdered sodium bicarbonate. This supension was then filtered and the filtrate was washed with two 50 ml portions of ice-water and dried over 20-30 g of anhydrous potassium carbonate for 10-15 hr. The solution was finally filtered and distilled under reduced pressure, b.p. 96-136 , 12-20 torr (lit. 58-62 ,... 

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