Abstract:
The invention relates to an improved process for the preparation of poly- .alpha.-glutamic acids which comprises the polymerisation of tertiary .gamma .-esters of .alpha.-glutamic acid N-carboxy anhydride with appropriate solve nts and initiators, followed by acid hydrolysis of the resulting poly-.alpha .-glutamic acid-.gamma.-ester. The process is particularly advantageous in t hat it allows to carefully control the molecular weight of the resulting pol y-.alpha.-glutamic acid. The invention also relates to poly-.alpha.-glutamic acids capped at the amino terminus with carboxylic acids or amino acids and to a process for the preparation thereof.
Abstract:
Un procedimiento para la preparación de ácido poli-α-glutámico de fórmula (I)en la que el símbolo * indica un centro quiral, n es un número entre 60 y 310, de forma que el ácido poli-α-glutámico tiene un peso molecular que se encuentra en el intervalo de 8.000 a 40.000 Da,comprendiendo dicho procedimiento las etapas de:a) polimerización de un éster terciario del N-carboxi anhídrido del ácido α-glutámico de fórmula (II)en la que el símbolo * es como se definió anteriormente, y R se elige entre t-butilo, 1,1-dimetilpropilo y 1,1-dimetilbutilo, en agua o en un disolvente orgánico elegido entre: tetrahidrofurano, 1,4-dioxano, dimetilformamida,mezclas de 1,4-dioxano y DMF y de 1,4-dioxano y tetrahidrofurano, con un iniciador elegido entre terc-butóxidode potasio, metóxido de sodio, diisopropiletilamina, 1,8-diazabiciclo [5,4,0] undec-7-eno, dimetilaminopiridina y γ-terc-butil éster del ácido L glutámico, para dar un compuesto de fórmula (III)en la que * y R son como se han definido anteriormente y R' es hidrógeno cuando el iniciador se elige entre diisopropiletilamina,1,8-diazabiciclo [5,4,0] undec-7-eno, 4-dimetilaminopiridina, dimetil éster del ácido glutámico y γ-terc-butil éster del ácido glutámico, o R' es un grupo t-butilo o metilo cuando el iniciador es el terc-butóxido depotasio y metóxido de sodio, respectivamente, y seguida porb) la hidrólisis ácida de los grupos éster γ- y α- para dar un compuesto de fórmula (I).
Abstract:
The invention relates to an improved process for the preparation of poly-α-glutamic acids which comprises the polymerisation of tertiary γ-esters of α-glutamic acid N-carboxy anhydride with appropriate solvents and initiators, followed by acid hydrolysis of the resulting poly-α-glutamic acid-γ-ester. The process is particularly advantageous in that it allows to carefully control the molecular weight of the resulting poly-α-glutamic acid. The invention also relates to poly-α-glutamic acids capped at the amino terminus with carboxylic acids or amino acids and to a process for the preparation thereof.
Abstract:
The invention relates to an improved process for the preparation of poly-α-glutamic acids which comprises the polymerisation of tertiary γ-esters of α-glutamic acid N-carboxy anhydride with appropriate solvents and initiators, followed by acid hydrolysis of the resulting poly-α-glutamic acid-γ-ester. The process is particularly advantageous in that it allows to carefully control the molecular weight of the resulting poly-α-glutamic acid. The invention also relates to poly-α-glutamic acids capped at the amino terminus with carboxylic acids or amino acids and to a process for the preparation thereof.
Abstract:
The invention relates to an improved process for the preparation of poly-α-glutamic acids which comprises the polymerisation of tertiary γ-esters of α-glutamic acid N-carboxy anhydride with appropriate solvents and initiators, followed by acid hydrolysis of the resulting poly-α-glutamic acid-γ-ester. The process is particularly advantageous in that it allows to carefully control the molecular weight of the resulting poly-α-glutamic acid. The invention also relates to poly-α-glutamic acids capped at the amino terminus with carboxylic acids or amino acids and to a process for the preparation thereof.