ethyl 2-chloro-3-oxopentanoate

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

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

Procedure: Sulphuryl chloride (286 g.) was added dropwise to a solution of ethyl 3-oxopentanoate (300 g.) in chloroform (250 ml.) at 10°-15°. Following addition the mixture was stirred overnight at room temperature, heated under reflux for 0.5 hours and cooled. After washing with water, sodium bicarbonate and water, the solution was dried (sodium sulphate), concentrated, and fractionated to yield ethyl 2-chloro-3-oxopentanoate, b.p. 94°-96°/14 mm. addition the mixture heated under reflux for 0.5 hours cooled After washing with water, sodium bicarbonate and water the solution was dried (sodium sulphate) concentrated

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

Procedure: Sulphuryl chloride (286 g.) was added dropwise to a solution of ethyl 3-oxopentanoate (300 g.) in chloroform (250 ml.) at 10°-15°. Following addition the mixture was stirred overnight at room temperature, heated under reflux for 0.5 hour and cooled. After washing with water, sodium bicarbonate and water, the solution was dried (sodium sulphate), concentrated, and fractionated to yield ethyl 2-chloro-3-oxopentanoate, b.p. 94°-96°/14 mm. addition the mixture heated under reflux for 0.5 hour cooled After washing with water, sodium bicarbonate and water the solution was dried (sodium sulphate) concentrated

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

Procedure: Sulphuryl chloride (286 g.) was added dropwise to a solution of ethyl 3-oxopentanoate (300 g.) in chloroform (250 ml.) at 10°-15°. Following addition the mixture was stirred overnight at room temperature, heated under reflux for 0.5 hour and cooled. After washing with water, sodium bicarbonate and water, the solution was dried (sodium sulphate), concentrated, and fractionated to yield ethyl 2-chloro-3-oxopentanoate, b.p. 94°-96°/14 mm. addition the mixture heated under reflux for 0.5 hour cooled After washing with water, sodium bicarbonate and water the solution was dried (sodium sulphate) concentrated

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

Procedure: Ethyl 2-chloro-3-oxopentanoate (29.2 g, 0.164 mol) prepared by the method of E. A. Falco, P. B. Russell and G. H. Hitchings, J. Am. Chem. Soc 1951, 73, 3753, and ammonium formate (60 g, 0.95 mol ) were heated in 100% formic acid (180 ml ) under reflux for 5 h. The cooled mixture was diluted with water (300 ml) and diethyl ether (200 ml), then neutralised with aqueous sodium hydroxide (5M). The layers were separated and the aqueous layer extracted with more ether (4×200 ml). The combined ether layers were dried over magnesium sulphate and the solvent removed by distillation at atmospheric pressure. Vacuum distillation of the residue yielded the desired oxazole (11.2 g, 40%) b.p. 100°-106° (7 mm). This was contaminated with starting material. An analytical sample, obtained by extracting into 5M sulphuric acid, had b.p. 97°-98° (7 mm) . (Found C, 56.64; H, 6.63; N, 8.24; C8H11NO3 requires: C, 56.80; H, 6.55; N, 6.28%); m/e 169 (M+); δ (360 MHz, CDCl3) 1.27 (3H, J=7.5 Hz, ArCH2CH3); 1.40 (3H, t, J=7 Hz, CO2CH2CH3); 2.91 (2H, q, J=7.5 Hz, arCH2CH3); 4.40 (2H, q, J=7 Hz, CO2CH2CH3); 7.89 (1H, s, ArH). under reflux for 5 h The layers were separated the aqueous layer extracted with more ether (4×200 ml) The combined ether layers were dried over magnesium sulphate the solvent removed by distillation at atmospheric pressure Vacuum distillation of the residue

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

Procedure: A mixture of 7.0 grams (0.028 mole) of 3-undecylphenol (prepared in Steps A-C of this Example) and 1.1 grams (0.028 mole) of 60% sodium hydride (in mineral oil) in 100 mL of toluene was stirred for about 20 minutes, and 4.2 grams (0.028 mole) of ethyl 2-chloro-3-oxopentanoate (prepared in Step D of this example) was added dropwise during about a 12 minute period. Upon completion of addition, the reaction mixture was heated to reflux, where it was stirred for about 6.5 hours. After this time, the reaction mixture was allowed to cool to ambient temperature, where it stood for about 16 hours. The reaction mixture was then taken up in 50 mL of water and 5 mL of acetic acid. The mixture was washed with an additional 50 mL of water and then with 25 mL of an aqueous solution saturated with sodium chloride. The organic layer was dried with sodium sulfate and filtered. The filtrate was concentrated under reduced pressure, yielding 8.9 grams of ethyl 2-(3-undecylphenoxy)-3-oxopentanoate. The NMR spectrum was consistent with the proposed structure. was added dropwise during about a 12 minute period Upon completion of addition the reaction mixture was heated to reflux where it was stirred for about 6.5 hours where it stood for about 16 hours The mixture was washed with an additional 50 mL of water The organic layer was dried with sodium sulfate filtered The filtrate was concentrated under reduced pressure

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

Procedure: Ethyl 3-oxopentanoate, 20.0 grams (0.175 mole), was stirred at ambient temperature, and 23.6 grams (0.175 mole) of sulfuryl chloride was added dropwise during a 20 minute period. Upon completion of addition, the reaction mixture was stirred for about 16 hours. The reaction mixture was then distilled under reduced pressure, yielding 23.3 grams of ethyl 2-chloro-3-oxopentanoate; bp 100°-103° C. at 21mm. Upon completion of addition The reaction mixture was then distilled under reduced pressure

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

Procedure: Sulphuryl chloride (286 g.) was added dropwise to a solution of ethyl 3-oxopentanoate (300 g.) in chloroform (250 ml.) at 10°-15°. Following addition the mixture was stirred overnight at room temperature, heated under reflux for 0.5 hours and cooled. After washing with water, sodium bicarbonate and water, the solution was dried (sodium sulphate), concentrated, and fractionated to yield ethyl 2-chloro-3-oxopentanoate, b.p. 94°-96°/14 mm. addition the mixture heated under reflux for 0.5 hours cooled After washing with water, sodium bicarbonate and water the solution was dried (sodium sulphate) concentrated

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

Procedure: Sulphuryl chloride (286 g.) was added dropwise to a solution of ethyl 3-oxopentanoate (300 g.) in chloroform (250 ml.) at 10°-15°. Following addition the mixture was stirred overnight at room temperature, heated under reflux for 0.5 hours and cooled. After washing with water, sodium bicarbonate and water, the solution was dried (sodium sulphate), concentrated, and fractionated to yield ethyl 2-chloro-3-oxopentanoate, b.p. 94°-96°/14 mm. addition the mixture heated under reflux for 0.5 hours cooled After washing with water, sodium bicarbonate and water the solution was dried (sodium sulphate) concentrated

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

Procedure: Sulphuryl chloride (286 g.) was added dropwise to a solution of ethyl 3-oxopentanoate (300 g.) in chloroform (250 ml.) at 10°-15°. Following addition the mixture was stirred overnight at room temperature, heated under reflux for 0.5 hours and cooled. After washing with water, sodium bicarbonate and water, the solution was dried (sodium sulphate), concentrated, and fractionated to yield ethyl 2-chloro-3-oxopentanoate, b.p. 94°-96°/14 nm. addition the mixture heated under reflux for 0.5 hours cooled After washing with water, sodium bicarbonate and water the solution was dried (sodium sulphate) concentrated

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

Procedure: Sulphuryl chloride (286 g.) was added dropwise to a solution of ethyl 3-oxopentanoate (300 g.) in chloroform (250 ml.) at 10°-15°. Following addition the mixture was stirred overnight at room temperature, heated under reflux for 0.5 hour and cooled. After washing with water, sodium bicarbonate and water, the solution was dried (sodium sulphate), concentrated, and fractionated to yield ethyl 2-chloro-3-oxopentanoate, b.p. 94°-96°/14 mm. addition the mixture heated under reflux for 0.5 hour cooled After washing with water, sodium bicarbonate and water the solution was dried (sodium sulphate) concentrated

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

Procedure: Sulphuryl chloride (286 g.) was added dropwise to a solution of ethyl 3-oxopentanoate (300 g.) in chloroform (250 ml.) at 10°-15°. Following addition the mixture was stirred overnight at room temperature, heated under reflux for 0.5 hour and cooled. After washing with water, sodium bicarbonate and water, the solution was dried (sodium sulphate), concentrated, and fractionated to yield ethyl 2-chloro-3-oxopentanoate, b.p. 94°-96°/14 mm. addition the mixture heated under reflux for 0.5 hour cooled After washing with water, sodium bicarbonate and water the solution was dried (sodium sulphate) concentrated