The present disclosure belongs to the field of chemical synthesis, and in particular relates to an ammonium carboxylate compound, a crystalline form and an amorphous form, and a preparation method thereof. The present disclosure prepares the compound and the crystalline form I and its single crystal, amorphous form and crystalline form II thereof. The compound, the crystalline forms, the single crystal and the amorphous form can stably exist and exhibit good solid forms, suitable for medicine-making. Furthermore, these products possess high purity and less single impurity. Moreover, the preparation methods of the present disclosure are easy to implement due to the simple processes with mild reaction conditions, and could produce products of high yield and high purity without complex purification steps. Furthermore, the preparation methods may facilitate safety, environmental protection, and industrial production.

The present disclosure belongs to the field of chemical synthesis, and in particular relates to an ammonium carboxylate compound, a crystalline form and an amorphous form, and a preparation method thereof. The present disclosure prepares the compound and the crystalline form I and its single crystal, amorphous form and crystalline form II thereof. The compound, the crystalline forms, the single crystal and the amorphous form can stably exist and exhibit good solid forms, suitable for medicine-making. Furthermore, these products possess high purity and less single impurity. Moreover, the preparation methods of the present disclosure are easy to implement due to the simple processes with mild reaction conditions, and could produce products of high yield and high purity without complex purification steps. Furthermore, the preparation methods may facilitate safety, environmental protection, and industrial production.

The present disclosure belongs to the field of chemical synthesis, and in particular relates to an ammonium carboxylate compound, a crystalline form and an amorphous form, and a preparation method thereof. The present disclosure prepares the compound and the crystalline form I and its single crystal, amorphous form and crystalline form II thereof. The compound, the crystalline forms, the single crystal and the amorphous form can stably exist and exhibit good solid forms, suitable for medicine-making. Furthermore, these products possess high purity and less single impurity. Moreover, the preparation methods of the present disclosure are easy to implement due to the simple processes with mild reaction conditions, and could produce products of high yield and high purity without complex purification steps. Furthermore, the preparation methods may facilitate safety, environmental protection, and industrial production.

The invention relates to a process for the preparation of Melphalan (4-[bis(2-chloroethyl)amino]-L-phenylalanine of formula (I)

##STR00001## said process comprising the reaction of a 4-amino-L-phenylalanine protected at the carboxy and amino aminoacidic groups with an agent able to convert the aromatic amino group into a group of formula: —N(CH.sub.2CH.sub.2OS(O).sub.nO.sup.−).sub.2, wherein n is 1 or 2 followed by conversion of the —N(CH.sub.2CH.sub.2OS(O).sub.nO.sup.−).sub.2 group into a —N(CH.sub.2CH.sub.2Cl).sub.2 group.

The invention also provides novel intermediates useful for the preparation of Melphalan.

The invention relates to a process for the preparation of Melphalan (4-[bis(2-chloroethyl)amino]-L-phenylalanine of formula (I)

##STR00001## said process comprising the reaction of a 4-amino-L-phenylalanine protected at the carboxy and amino aminoacidic groups with an agent able to convert the aromatic amino group into a group of formula: —N(CH.sub.2CH.sub.2OS(O).sub.nO.sup.−).sub.2, wherein n is 1 or 2 followed by conversion of the —N(CH.sub.2CH.sub.2OS(O).sub.nO.sup.−).sub.2 group into a —N(CH.sub.2CH.sub.2Cl).sub.2 group.

The invention also provides novel intermediates useful for the preparation of Melphalan.

The present disclosure is directed synthetic methods for the preparation of 4-valyloxybutyric acid. The synthetic methods described herein employ a diverse array of protecting group strategies and reaction conditions. Additionally, the present disclosure is directed to compounds useful as synthetic intermediates in the preparation of 4-valyloxybutyric acid.

The present disclosure is directed synthetic methods for the preparation of 4-valyloxybutyric acid. The synthetic methods described herein employ a diverse array of protecting group strategies and reaction conditions. Additionally, the present disclosure is directed to compounds useful as synthetic intermediates in the preparation of 4-valyloxybutyric acid.

The present disclosure is directed synthetic methods for the preparation of 4-valyloxybutyric acid. The synthetic methods described herein employ a diverse array of protecting group strategies and reaction conditions. Additionally, the present disclosure is directed to compounds useful as synthetic intermediates in the preparation of 4-valyloxybutyric acid.

The present disclosure is directed synthetic methods for the preparation of 4-valyloxybutyric acid. The synthetic methods described herein employ a diverse array of protecting group strategies and reaction conditions. Additionally, the present disclosure is directed to compounds useful as synthetic intermediates in the preparation of 4-valyloxybutyric acid.

The present disclosure is directed synthetic methods for the preparation of 4-valyloxybutyric acid. The synthetic methods described herein employ a diverse array of protecting group strategies and reaction conditions. Additionally, the present disclosure is directed to compounds useful as synthetic intermediates in the preparation of 4-valyloxybutyric acid.