ethyl 2-acetyl-3-oxobutanoate

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

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

Procedure: Similar to Example 1, equimolar amounts of 3-methoxyphenylhydrazine hydrochloride and 2-acetyl-3-oxo-butyric acid ethyl ester were combined in a Solution of 50% pyridine in ethanol. The resulting solid was determined to be the named product by 1H-NMR (CDCl3, ppm): 1.38 t (3H); 2.50 s (3H); 2.52 s (3H); 3.84 s (3H); 4.32 q (2H); 6.96 m (3H); 7.3 st (1H).

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

Procedure: Similar to Example 1, equimolar amounts of 3-fluorophenylhydrazine hydrochloride and 2-acetyl-3-oxo-butyric acid ethyl ester were combined in a solution of 50% pyridine in ethanol. Analysis showed that resulting solid was the named product (m.p. 55° C.-56.1° C.). that resulting solid

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

Procedure: Similar to Example 1, equimolar amounts of m-tolylhydrazine hydrochloride and 2-acetyl-3-oxo-butyric acid ethyl ester were combined in a solution of a 50% pyridine in ethanol. The resulting oil was purified by flash chromatography to yield the named product as a solid (m.p. 46.5° C.-47.5° C.). The resulting oil was purified by flash chromatography

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

Procedure: Similar to Example 1, equimolar amounts of 3-chlorophenylhydrazine hydrochloride and 2-acetyl-3-oxo-butyric acid ethyl ester were combined in a solution of 50% pyridine in ethanol. Analysis confirmed that the resulting solid was determined to be the named product (m.p. 56° C.-57° C.).

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

Procedure: Similar to Example 1, equimolar amounts of benzylhydrazine dihydrochloride and 2-acetyl-3-oxo-butyric acid ethyl ester were combined in a solution of 50% pyridine in ethanol. The resulting oil was determined to be the named product by 1H-NMR (CDCl3, ppm): 1.35 t (3H); 2.44 s (3H); 2.45 s (3H); 4.38 a (2H); 5.25 s (2H); 7.08 d (2H); 7.29 m (3H).

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

Procedure: Similar to Example 1, equimolar amounts of cyclohexyl hydrazine hydrochloride and 2-acetyl-3-oxobutyric Acid Ethyl Ester were combined in a solution of 50% pyridine in ethanol. Analysis confirmed synthesis of the named product (m.p. 66° C.-67° C.).

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

Procedure: Similar to Example 1, equimolar amounts of (5-nitropyridin-2-yl)hydrazine and 2-acetyl-3-oxo-butyric acid ethyl ester were combined in a solution of 50% pyridine in ethanol. Analysis confirmed synthesis of the named product (m.p. 117° C.-119° C.).

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

Procedure: Similar to Example 1, 2-pyridylhydrazine (7.5 mmol, 0.8 g) and 2-acetyl-3-oxo-butyric acid ethyl ester (7.5 mmol, 1.3 g) were mixed in a solution of 50% pyridine in ethanol, then heated under reflux. The solvents were removed under vacuum and the residue purified over silica. The named product crystallized upon standing (m.p. 49° C.-50° C.). heated under reflux The solvents were removed under vacuum the residue purified over silica The named product crystallized

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

Procedure: Similar to Example 1, o-nitrophenylhydrazine (20 mmol, 3.4 g) and 2-acetyl-3-oxo-butyric acid ethyl ester (20 mmol, 3.4 g) were mixed in a solution of 50% pyridine in ethanol and heated under reflux. The solvents then were removed under vacuum, and the residue was resuspended in chloroform. The resulting mixture was washed with water and dried over NaSO4. The solids then were filtered, and the solvents removed under vacuum. A precipitate formed when the oily solid was dissolved in a solution of 20% hexane in chloroform. The solid was collected and discarded, and the filtrate was purified over silica gel. The named product was contaminated, then was further purified by recrystallization from ethanol to yield a solid having a melting point of 128° C.-130° C. heated under reflux The solvents then were removed under vacuum The resulting mixture was washed with water dried over NaSO4 The solids then were filtered the solvents removed under vacuum A precipitate formed when the oily solid The solid was collected the filtrate was purified over silica gel was further purified by recrystallization from ethanol to yield a solid

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

Procedure: Similar to Example 1, p-tolylhydrazine (10 mmol, 1.8 g) and 2-acetyl-3-oxo-butyric acid ethyl ester (10 mmol, 1.7 g) were mixed in a solution of 50% pyridine in ethanol. The solvents were removed under vacuum. The named product was purified over silica gel (m.p. 47° C.-49° C.). The solvents were removed under vacuum The named product was purified over silica gel (m.p. 47° C.-49° C.)

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

Procedure: Similar to Example 1, phenyl hydrazine (7.5 mmol, 0.8 g) and 2-acetyl-3-oxo-butyric acid ethyl ester (7.5 mmol, 1.3 g) were mixed in a solution of 50% pyridine in ethanol. The solvents were removed under vacuum and the oil resuspended in chloroform. The resulting suspension was washed with 5% sodium bicarbonate, 5% hydrochloric acid, and then brine. The organic layer was dried over NaSO4, the solids filtered, and the solvents removed under vacuum. The crude material was purified over silica gel to yield the named product as an oil. 1H-NMR (CDCl3, ppm): 1.37 t (3H); 2.51 s (6H); 4.32 q (2H); 7.42 bs (5H). The solvents were removed under vacuum The resulting suspension was washed with 5% sodium bicarbonate, 5% hydrochloric acid The organic layer was dried over NaSO4 the solids filtered the solvents removed under vacuum The crude material was purified over silica gel