- Preparation method of (S)-1 - (benzyloxycarbonyl) -5 -oxo-pyrrolidine -2 - formic acid
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The invention discloses a preparation method of (S)-1 - (benzyloxycarbonyl) -5 -oxo-pyrrolidine -2 - formic acid, which mainly solves the complexity in the original process, and is long in period and high in cost. The method specifically comprises first steps of preparing L - benzyloxycarbonyl N - glutamic acid from - L - glutamic acid and a benzyloxycarbonyl donor, second steps of intramolecular condensation cyclization N - benzyloxycarbonyl - L - glutamic acid to obtain the N -benzyloxycarbonyl - L - glutamic acid crude product. The third The crude N - benzyloxycarbonyl - L - glutamic acid crude product and the organic amine base are mixed, and the organic amine salt form is prepared by the solubility of the product in a solvent, fourth (N -) - L - (benzyloxycarbonyl) S oxopyrrolidine -1 - formic acid is prepared by desalinating -5 - benzyloxycarbonyl -2 - glutamic acid. To the method, the high-purity product is prepared, and the yield and the quality are greatly improved.
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Paragraph 0042
(2021/09/01)
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- PROCESS FOR THE PREPARATION OF POMALIDOMIDE
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The present invention relates to a process for the preparation of pomalidomide. The present invention also provides a process for the preparation of 2-(2,6-dioxopiperidin-3-yl)-4-nitro-1H-isoindole-1,3(2H)-dione, a compound of Formula II and its use for the preparation of pomalidomide. The pomalidomide may be made having a yield greater than 97% and the 2-(2,6-dioxopiperidin-3-yl)-4-nitro-1H-isoindole-1,3(2H)-dione (Formula II) may be made having a yield greater than 88%.
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Page/Page column 6-7
(2018/09/19)
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- Preparation method of deuterated intermediate
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The present invention provides a preparation method of a deuterated intermediate. The deuterated intermediate has a structure shown by a formula I; the preparation method comprises the following steps: amino groups in a raw material A and an aldehyde grou
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Paragraph 0060; 0061; 0062; 0063; 0064; 0065
(2018/11/03)
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- Efficient synthesis of (2S)-tert-butyl 2-(2-bromopropanamido)-5-oxo-5-(tritylamino)pentanoate as a precursor of PET radiotracer [18F]FPGLN
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This study describes a convenient protocol for the synthesis of (2S)-tert-butyl 2-(2-bromopropanamido)-5-oxo-5-(tritylamino)pentanoate, which can serve as an appropriate precursor of (2S)-5-amino-2-(2-[18F]fluoropropanamido)-5-oxopentanoic acid
- Liu, Shaoyu,Tang, Xiaolan,Nie, Dahong,Jiang, Shende,Tang, Ganghua
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supporting information
p. 1136 - 1141
(2017/06/09)
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- (S)-2-methyl-1,4,5,6-tetrahydromethylpyrimidine-4-carboxylic acid synthesis method
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The present invention relates to a (S)-2-methyl-1,4,5,6-tetrahydromethylpyrimidine-4-carboxylic acid synthesis method. According to the method, L-glutamine is used as a raw material, the alpha-amino of the L-glutamine is protected with a protection group, a decarbonylating agent is added, a Hofmann degradation reaction is performed to remove the carbonyl group attached to the remaining amino, the protection group is removed to obtain L-2,4-diaminobutyric acid, and finally the prepared L-2,4-diaminobutyric acid and trimethyl orthoacetate are subjected to a ring forming reaction to obtain the (S)-2-methyl-1,4,5,6-tetrahydromethylpyrimidine-4-carboxylic acid. Compared to the method in the prior art, the method of the present invention has the following characteristics that the chemical synthesis route is provided, the steps of the synthesis process are simple, the raw materials are easy to obtain, the product purity is high, and the method is suitable for large-scale industrial production.
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Paragraph 0050; 0051; 0052
(2017/08/30)
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- Preparation method of Nalpha-fluorenylmethoxycarbonyl-glutamine tert-butyl ester
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The invention discloses a preparation method of Nalpha-fluorenylmethoxycarbonyl-glutamine tert-butyl ester and mainly solves the technical problems of complexity, long period, low yield, high cost and the like of an original technology. The preparation method comprises steps as follows: step one, gln and tert-butyl acetate are mixed, and h-gln-otbu is prepared under the action of perchloric acid; or, gln and z-cl are mixed, z-gln-oh is prepared and mixed with tert-butyl acetate, z-gln-otbu is prepared and subjected to catalytic hydrogenation in methyl alcohol, and h-gln-otbu is prepared; step two, h-gln-otbu and a fmoc-group protective agent are mixed, pH value is regulated to 8-9 by an alkali compound sodium carbonate aqueous solution in the presence of an organic solvent, fmoc-gln-otbu is prepared through reaction, and a pure product of fmoc-gln-otbu is prepared through processing. With the adoption of setting of a reasonable process route, Nalpha-fluorenylmethoxycarbonyl-glutamine tert-butyl ester and an intermediate thereof are prepared, and Nalpha-fluorenylmethoxycarbonyl-glutamine tert-butyl ester is applicable to mass production.
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Paragraph 0031
(2017/01/17)
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- Solution phase synthetic approach to fellutamide B
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Abstract A convenient solution phase approach for the synthesis of fellutamide B with efficient purification techniques has been demonstrated on the molecule for the first time. The strategy involves the use of natural amino acids as starting materials and classical peptide coupling reactions. The synthesis has been achieved in 10 steps with overall yield of 26.7% making the synthesis facile.
- Yadav, Jhillu Singh,Dachavaram, Soma Shekar,Grée, René,Das, Saibal
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supporting information
p. 3999 - 4001
(2015/06/08)
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- COMPOSITIONS AND METHODS FOR PROTECTING CELLS FROM TOXIC EXPOSURES
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The present invention provides compositions and methods for protecting cells and tissues from damage associated with therapeutic treatments of cancers and other diseases and conditions where reactive oxygen species are produced. The present invention also
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Page/Page column 32
(2008/12/04)
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- Utility of tetrathiomolybdate and tetraselenotungstate: Efficient synthesis of cystine, selenocystine, and their higher homologues
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Efficient synthesis of cystine, selenocystine, and their higher homologues like homo and bishomo amino acid derivatives from natural amino acid derivatives using tetrathiomolybdate and tetraselenotungstate reagents under mild and neutral conditions is reported. The generality of the reaction has been studied by capping various groups to amino and carboxyl components of canonical amino acids.
- Bhat, Ramakrishna G.,Porhiel, Emmanuel,Saravanan, Vadivelu,Chandrasekaran, Srinivasan
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p. 5251 - 5253
(2007/10/03)
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- Chemoselective alkoxycarbonylation reagent having trifluoromethylsulfonyl-4-trifluoromethylanilide as a leaving group
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N-Benzyloxy- and N-tert-butoxycarbonyltrifluoromethylsulfonyl-4-trifluoromethylanilides were prepared and were found to be chemoselective and shelf-storable alkoxycarbonylation reagents.
- Yasuhara, Tomohisa,Nagaoka, Yasuo,Tomioka, Kiyoshi
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p. 2233 - 2234
(2007/10/03)
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- New reaction conditions using trifluoroethanol for the E-I Hofmann rearrangement
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The Hofmann rearrangement of -protected glutamine esters to N2-protected (2S)-4-[(2,2,2-trifluoroethoxy)carbonyIamino]-2-aminobutyric acid esters was successfully achieved by an electrochemical method using a trifluoroethanol (TFE)-MeCN solvent system where the TFE may play an important role in controlling the basicity caused by electrochemically generated bases.
- Matsumura, Yoshihiro,Yuki Satoh, Kimihiro Shirai,Onomura, Osamu,Toshihide, Maki
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p. 2057 - 2060
(2007/10/03)
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- 3-Alkoxycarbonyl-2-oxazolones and Their Homopolymers as Highly Preservable Amino-Protecting Reagents. tert-Butoxy-carbonylation and Benzyloxycarbonylation of Amino Groups
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Highly preservable amino protecting reagents derived from the 2-oxazolone moiety as a common activating mediator have been developed. 3-Alkoxycarbonyl-2-oxazolones serve as easily handled reagents for amino protection, including tert-butoxycarbonylation, benzyloxycarbonylation, p-methoxybenzyloxycarbonylation, methoxycarbonylation and ethoxycarbonylation.For example, high yield N-protection of α-amino acids has been smoothly performed by the use of 3-tert-butoxycarbonyl and 3-benzyloxycarbonyl-2-oxazolones in aqueous solution at room temperature.A series of homopolymers, poly(3-alkoxycarbonyl-2-oxazolone), is readily obtainable by radical-initiated chain reaction of the corresponding 4,5-unsubstituted oxazolone monomers (except for the tert-butoxy derivate, which failed to give polymeric compounds), and these were successfully used for amino protection as well.Use of the polymer reagents greatly simplifies the purification procedure, though a longer reaction time is required.Keywords - 3-alkoxycarbonyl-2-oxazolone; poly(2-alkoxycarbonyl-2-oxazolone); 3-tert-butoxycarbonyl-2-oxazolone; 3-benzyloxycarbonyl-2-oxazolone; amino protection
- Kunieda, Takehisa,Higuchi, Tsunehiko,Abe, Yoshihiro,Hirobe, Masaaki
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p. 2174 - 2181
(2007/10/02)
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