(2S)-2-amino-2,3-dimethylbutanamide

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

Procedure: 6.3 g (28.48 mmol) 5-acetoxy-6-methyl-pyridine-2,3-dicarboxylic acid anhydride and 4.1 g (31.33 mmol) 2-methyl-valinamide are stirred under nitrogen for 2 days at room temperature, and then the precipitated crystalline product is filtered off. the precipitated crystalline product is filtered off

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

Procedure: A mixture of 77 g of ethyl 2-chloromethyl-5-ethylnicotinate (0.338 mol), 44 g of α-methylvalinamide (0.338 mol) and 33.5 g of sodium bicarbonate (0.4 mol) in 60 mL dimethylsulfoxide is stirred and heated at 80° for 16 hours. The reaction is partitioned between 1:1 ethylacetate-hexane and water. The organic layer is washed thoroughly with water, dried, and concentrated in vacuo to a gum. Chromatography of this gum on silica gel using hexane-ethyl acetate mixtures as eluant affords the title product, mp 68°-72°. heated at 80° for 16 hours The reaction is partitioned between 1:1 ethylacetate-hexane and water The organic layer is washed thoroughly with water dried concentrated in vacuo to a gum

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

Procedure: A mixture of 77 g of ethyl 2-chloromethyl-5-ethylnicotinate (0.338 mol), 44 g of α-methylvalinamide (0.338 mol) and 33.5 g of sodium bicarbonate (0.4 mol) in 60 mL dimethylsulfoxide is stirred and heated at 80° for 16 hours. The reaction is partitioned between 1:1 ethylacetate-hexane and water. The organic layer is washed thoroughly with water, dried, and concentrated in vacuo to a gum. Chromatography of this gum on silica gel using hexane-ethyl acetate mixtures as eluant affords the title product, mp 68°-72°. heated at 80° for 16 hours The reaction is partitioned between 1:1 ethylacetate-hexane and water The organic layer is washed thoroughly with water dried concentrated in vacuo to a gum

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

Procedure: A mixture of 77 g of ethyl 2-chloromethyl-5-ethylnicotinate (0.338 mol), 44 g of α-methylvalinamide (0.338 mol) and 33.5 g of sodium bicarbonate (0.4 mol) in 60 mL dimethylsulfoxide is stirred and heated at 80° for 16 hours. The reaction is partitioned between 1:1 ethylacetate-hexane and water. The organic layer is washed thoroughly with water, dried, and concentrated in vacuo to a gum. Chromatography of this gum on silica gel using hexane-ethyl acetate mixtures as eluant affords the title product, mp 68°-72°. heated at 80° for 16 hours The reaction is partitioned between 1:1 ethylacetate-hexane and water The organic layer is washed thoroughly with water dried concentrated in vacuo to a gum

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

Procedure: A mixture of 77 g of ethyl 2-chloromethyl-5-ethylnicotinate (0.338 mol), 44 g of α-methylvalinamide (0.338 mol) and 33.5 g of sodium bicarbonate (0.4 mol) in 60 mL dimethylsulfoxide is stirred and heated at 80° for 16 hours. The reaction is partitioned between 1:1 ethylacetate-hexane and water. The organic layer is washed thoroughly with water, dried, and concentrated in vacuo to a gum. Chromatography of this gum on silica gel using hexane-ethyl acetate mixtures as eluant affords the title product, mp 68°-72°. heated at 80° for 16 hours The reaction is partitioned between 1:1 ethylacetate-hexane and water The organic layer is washed thoroughly with water dried concentrated in vacuo to a gum

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

Procedure: A mixture of 77 g of ethyl 2-chloromethyl-5-ethylnicotinate (0.338 mol), 44 g of α-methylvalinamide (0.338 mol) and 33.5 g of sodium bicarbonate (0.4 mol) in 60 mL dimethylsulfoxide is stirred and heated at 80° for 16 hours. The reaction is partitioned between 1:1 ethylacetate-hexane and water. The organic layer is washed thoroughly with water, dried, and concentrated in vacuo to a gum. Chromatography of this gum on silica gel using hexane-ethyl acetate mixtures as eluant affords the title product, mp 68°-72°. heated at 80° for 16 hours The reaction is partitioned between 1:1 ethylacetate-hexane and water The organic layer is washed thoroughly with water dried concentrated in vacuo to a gum

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

Procedure: 6.3 g (28.48 mmol) 5-acetoxy-6-methyl-pyridine-2,3-dicarboxylic acid anhydride and 4.1 g (31.33 mmol) 2-methylvalinamide are stirred under nitrogen for 2 days at room temperature, and then the precipitated crystalline product is filtered off. the precipitated crystalline product is filtered off

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

Procedure: 6.3 g (28.48 mmol) 5-acetoxy-6-methyl-pyridine-2,3-dicarboxylic acid anhydride and 4.1 g (31.33 mmol) 2-methylvalinamide are stirred under nitrogen for 2 days at room temperature, and then the precipitated crystalline product is filtered off. the precipitated crystalline product is filtered off

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

Procedure: 6.3 g (28.48 mmol) 5-acetoxy-6-methyl-pyridine-2,3-dicarboxylic acid anhydride and 4.1 g (31.33 mmol) 2-methyl-valinamide are stirred under nitrogen for 2 days at room temperature, and then the precipitated crystalline product is filtered off. the precipitated crystalline product is filtered off

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

Procedure: 6.3 g (28.48 mmol) 5-acetoxy-6-methyl-pyridine-2,3-dicarboxylic acid anhydride and 4.1 g (31.33 mmol) 2-methyl-valinamide are stirred under nitrogen for 2 days at room temperature, and then the precipitated crystalline product is filtered off. the precipitated crystalline product is filtered off

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

Procedure: A mixture of 2.2 g of sec-butyl 5-ethyl-2-methylnicotinate (10 mmol), 1.3 g of a-methylvalinamide (10 mmol) and 2.0 g of sulfur (62 mmol) in 2.5 g of chlorobenzene (114 wt%) is magnetically stirred at reflux temperatures for 24 hours. The reaction is cooled, diluted with methylene chloride, and filtered to remove unreacted sulfur. The filtrate is chromatographed on silica gel using 2:1 hexane-ethyl acetate as eluant to afford 2.5 g of the title product (72% yield) as a solid; recrystallization from ether-hexane gives mp 83°-87° C. at reflux temperatures for 24 hours The reaction is cooled filtered to remove unreacted sulfur The filtrate is chromatographed on silica gel using 2:1 hexane-ethyl acetate as eluant

Conditions: temp:10.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of N,N-diethyl-5,6-)methylenedioxy)phthalamic acid (3.00 g, 11.0 mmol) in tetrahydrofuran, under nitrogen at room temperature is treated with ethyl chloroformate (1.10 mL, 11.0 mmol), cooled to 10° C., treated with triethylamine (1.70 mL, 12.0 mmol), stirred for 30 minutes at 10° C., treated dropwise with a solution of α-methylvalinamide (1.43 g, 11.0 mmol) in tetrahydrofuran, stirred overnight at ambient temperatures, treated with water and concentrated in vacuo. The aqueous residue is extracted with ethyl acetate; the extracts are combined, washed with brine and saturated sodium bicarbonate, dried (MgSO4), and concentrated in vacuo to afford the title product as an amber foam 3.10 g (74.7%), identified by NMR and mass spectral analysis. stirred overnight at ambient temperatures concentrated in vacuo The aqueous residue is extracted with ethyl acetate washed with brine and saturated sodium bicarbonate dried (MgSO4) concentrated in vacuo