Methyl L-pyroglutamate synthesis
- Product Name:Methyl L-pyroglutamate
- CAS Number:4931-66-2
- Molecular formula:C6H9NO3
- Molecular Weight:143.14
98-79-3
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$5.00/25g
4931-66-2
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$10.00/5g
Yield:4931-66-2 92.8%
Reaction Conditions:
with sulfuryl dichloride;sodium carbonate in methanol;ethyl acetate
Steps:
14.a 14a.
14a. (S)-Pyroglutamic Acid Methyl Ester Sulfuryl chloride (388 mL, 5.31 mol) was added dropwise to methanol (930 mL), protected from moisture and cooled in an ice bath to keep the temperature under 15° C. When the addition was complete and the temperature had fallen to 4° C., (S)-pyroglutamic acid (301 g, 2.33 mol, Sigma Chemical Co.) was added in one portion. The ice bath was allowed to melt and the reaction mixture was stirred at ambient temperature for 16 hours. The solvent was removed on a rotary evaporator leaving 471 g of the crude product as a thick oil. Ethyl acetate (4 L), sodium carbonate (100 g), and 2M aqueous sodium carbonate (150 mL) were added, and the mixture was stirred vigorously for 1 hour. The organic layer was decanted from the semi-solid inorganic residue, and the residue was extracted with ethyl acetate. The organic fractions were combined and reduced on the rotary evaporator to give 343 g of thick yellow oil. The crude ester was vacuum distilled at 143°- 145° C. and 0.35 torr to afford the title product (309.6 g, 92.8 % yield) as a colorless oil.
References:
Abbott Laboratories US5424444, 1995, A
67-56-1
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149-87-1
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$6.00/25g
4931-66-2
264 suppliers
$10.00/5g
