dibenzyl carbonate

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

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

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

Procedure: 101.6 g of dibenzyl carbonate, 23.6 g of trimethylamine, 60.5 g of water and 20.0 g of methanol were introduced in the same reactor as used in Preparation Example 1 and heated with stirring. After the temperature in the reactor reached 150° C., the reaction was continued for 5 hours at 150° C. Trimethylbenzylammonium hydrogencarbonate was obtained in a yield of 81.0 mol % (based on trimethylamine). as used in Preparation Example 1 heated reached 150° C.

Conditions: temp:-75.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a flame-dried 50 ml three necked flask under argon atmosphere were dissolved 1.27 g (10.0 mmol) of 5,5-dimethylpyrrolidin-2-one in 10 ml of dry THF. After cooling to −75° C., a 2 M solution of lithium diisopropylamide in THF (10.5 ml, 10.5 mmol) was added dropwise maintaining the temperature below −73° C. The solution was stirred for 1 h at −75° C. Then a solution of dibenzyl carbonate (2.72 g, 11.0 mmol) in 5 ml of THF was added dropwise at −75° C., allowed to warm up to r.t. and stirred for 1 h. The reaction was quenched by addition of 5 ml of saturated ammonium chloride solution. After extraction with ethyl acetate/water, drying over sodium sulfate and concentration; the residue was loaded onto a 50 g prepacked flash chromatography column. After elution with a 10% to 70% ethyl acetate in heptane gradient, the fractions containing the desired product were collected to yield 1.07 g (41%) of the title compound as a light yellow oil, MS: m/e=262.2 (M+H+). maintaining the temperature below −73° C to warm up to r.t. stirred for 1 h The reaction was quenched by addition of 5 ml of saturated ammonium chloride solution After extraction with ethyl acetate/water drying over sodium sulfate and concentration After elution with a 10% to 70% ethyl acetate in heptane gradient the fractions containing the desired product were collected

Conditions: temp:-75.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a flame-dried 50 ml three necked flask under argon atmosphere were dissolved 1.27 g (10.0 mmol) of 5,5-dimethylpyrrolidin-2-one in 10 ml of dry THF. After cooling to −75° C., a 2 M solution of lithium diisopropylamide in THF (10.5 ml, 10.5 mmol) was added dropwise maintaining the temperature below −73° C. The solution was stirred for 1 h at −75° C. Then a solution of dibenzyl carbonate (2.72 g, 11.0 mmol) in 5 ml of THF was added dropwise at −75° C., allowed to warm up to r.t. and stirred for 1 h. The reaction was quenched by addition of 5 ml of saturated ammonium chloride solution. After extraction with ethyl acetate/water, drying over sodium sulfate and concentration; the residue was loaded onto a 50 g prepacked flash chromatography column. After elution with a 10% to 70% ethyl acetate in heptane gradient, the fractions containing the desired product were collected to yield 1.07 g (41%) of the title compound as a light yellow oil, MS: m/e=262.2 (M+H+). maintaining the temperature below −73° C to warm up to r.t. stirred for 1 h The reaction was quenched by addition of 5 ml of saturated ammonium chloride solution After extraction with ethyl acetate/water drying over sodium sulfate and concentration After elution with a 10% to 70% ethyl acetate in heptane gradient the fractions containing the desired product were collected

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

Procedure: The 2nd step is carried out analogously in further experiments B, C, and D at room temperature using the dibenzyl carbonate and hydrazine hydrate ratios given in Table 1. The amount and purity of benzyl carbazate that is obtained are likewise summarized in Table 1. is carried out analogously in further experiments B, C, and D at room temperature

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

Procedure: 101.6 g of dibenzyl carbonate, 23.6 g of trimethylamine, 60.5 g of water and 20.0 g of methanol were introduced in the same reactor as used in Preparation Example 1 and heated with stirring. After the temperature in the reactor reached 150° C., the reaction was continued for 5 hours at 150° C. Trimethylbenzylammonium hydrogencarbonate was obtained in a yield of 81.0 mol % (based on trimethylamine). as used in Preparation Example 1 heated reached 150° C.