- Method for preparing cysteamine hydrochloride
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The invention relates to a method for preparing cysteamine hydrochloride. The method comprises the following steps: 1, reacting carbon disulfide with sodium sulfide in alcohol to obtain sodium thiocarbonate; 2, fully reacting 2-aminoethyl sulfate sodium salt or 2-chloroethylamine hydrochloride with the sodium thiocarbonate prepared in the step 1; 3, continuing to add hydrochloric acid for a reaction to obtain first-stage cysteamine hydrochloride mother liquor; 4, cooling and crystallizing the cysteamine hydrochloride mother liquor obtained in the step 3 to crystallize sodium sulfate and/or sodium chloride generated in the reaction in the step 2, and carrying out filtering after crystallization to obtain a filtrate which is second-stage cysteamine hydrochloride mother liquor; 5, carrying out reduced-pressure distillation on the second-stage cysteamine hydrochloride mother liquor obtained in the step 4, and carrying out cooling and crystallizing to obtain a cysteamine hydrochloride solid, wherein a ratio of the 2-aminoethyl sulfate sodium salt to the 2-chloroethylamine hydrochloride is 1: 1. Through further optimization, yield is further increased, and the mass yield can reach 95% interms of sodium sulfide.
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Paragraph 0032; 0035-0038
(2020/03/09)
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- Synthesis and antiproliferative activities of conjugates of paclitaxel and camptothecin with a cyclic cell-penetrating peptide
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Cell-penetrating peptide [WR]5 has been previously shown to be an efficient molecular transporter for various hydrophilic and hydrophobic molecules. The peptide was synthesized using Fmoc/tBu solid-phase chemistry, and one arginine was replaced with one lysine to enable the conjugation with the anticancer drugs. Paclitaxel (PTX) was functionalized with an esterification reaction at the C20 hydroxyl group of PTX with glutaric anhydride and conjugated with the cyclic peptide [W(WR)4K(βAla)] in DMF to obtain the peptide-drug conjugate PTX1. Furthermore, camptothecin (CPT) was modified at the C(20)-hydroxyl group through the reaction with triphosgene. Then, it was conjugated with two functionalized cyclic peptides through a formyl linker affording two different conjugates, namely CPT1 and CPT2. All the conjugates showed better water solubility as compared to the parent drug. The cytotoxicity assay of the drugs and their conjugates with the peptides were evaluated in the human breast cancer MCF-7 cell line. PTX inhibited cell proliferation by 39% while the PTX-peptide conjugate inhibited the proliferation by ~18% after 72 h incubation. On the other hand, CPT, CPT1, and CPT2 reduced the cell proliferation by 68%, 39%, and 62%, respectively, in the MCF-7 cell lines at 5 μM concentration after 72 h incubation.
- El-Sayed, Naglaa Salem,Shirazi, Amir Nasrolahi,Sajid, Muhammad Imran,Park, Shang Eun,Parang, Keykavous,Tiwari, Rakesh Kumar
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- Method for synthesizing cysteamine hydrochloride from sodium tetrathiocarbonate
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Disclosed is a method for synthesizing cysteamine hydrochloride from sodium tetrathiocarbonate. The method comprises the following steps of heating and refluxing carbon disulfide and sodium sulfate solution into a reactor for reaction to obtain sodium tetrathiocarbonate solution; dropwise adding sodium 2-aminoethyl sulfate solution or 2-chloroethylamine hydrochloride with a concentration of 25-30%into the sodium tetrathiocarbonate solution at 40-50 DEG C within 1.5-2.5 h, half an hour later, increasing the temperature to 58-62 DEG C for further reaction unital the sodium tetrathiocarbonate solution turns colorless; adding in hydrochloric acid for reaction, of which the produced carbon disulfide can be recycled; performing reduced-pressure distillation and concentration and then cooled crystallization on the reacted solution to obtain the crystal of sodium sulfate or sodium chloride and the filter liquor of cysteamine hydrochloride aqueous solution; performing reduced-pressure distillation on the cysteamine hydrochloride aqueous solution to remove all water, and then cooling the solids down to obtain the finished cysteamine hydrochloride. The method for synthesizing the cysteaminehydrochloride from the sodium tetrathiocarbonate simplifies the processes and saves the production costs, and the prepared cysteamine hydrochloride is high in yield and purity.
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Paragraph 0030; 0033-0036
(2019/04/17)
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- PROCESS FOR THE PREPARATION OF A SULFUR-AMINE
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The present invention relates to a process for the synthesis of cysteamine or a salt thereof.
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Paragraph 0040; 0041
(2018/05/03)
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- Synthesis of mercaptoethylammonium chloride in alkaline medium
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A new way synthesis of mercaptoethylammonium chloride is reported. Using NaOH replace HCl, the results present that the target product can be made in alkaline medium and the velocity of new way is much faster than the tradition one, which is hydrolyzed at high pressure. 1H NMR and IR characterized the structure of the product.
- Xiao, Feng,Tan, Shiyu,Zou, Xiaobing
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experimental part
p. 3247 - 3248
(2012/08/29)
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- Synthesis of cysteamine hydrochloride by high pressure acidolysis of 2-mercaptothiazoline
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The synthesis of cysteamine hydrochloride by high pressure acidolysis of 2-mercaptothiazoline was investigated and the result showed that the high pressure acidolysis can significantly increase the reaction rate as well as the product yield. Characterization by melting point, purity analysis, IR and 1H NMR proved that the synthesized product is cysteamine hydrochloride with purity as high as 98.9 %. The reaction pressure and molar ratio between the reactants were demonstrated to have significant impacts on the product yield. The optimum conditions for the acidolysis reaction obtained via a group of orthogonal experiments are: reaction pressure, 0.3 MPa; mole ratio between 2-mercaptothiazoline to HCl (20 wt %), 1:5; reaction time, 7 h. Under the optimum conditions, the yield of cysteamine hydrochloride can reach 95.6 %.
- Cui, Ying,Tan, Shiyu,Luo, Ziping,Dong, Lichun
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experimental part
p. 3221 - 3227
(2010/11/05)
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- Preparation of addition salts of cysteamine with acids
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Addition salts of cysteamine with acids are prepared by reacting aziridine with an organic sulfur compound of oxidation state -2 and with a ketone and then subjecting the thiazolidine formed as an intermediate to acid hydrolysis, by a process in which aziridine and the ketone are reacted with ammonium hydrogen sulfide or with a metal hydrogen sulfide with the addition of a moderately strong or strong acid at from -10° to +100° C. and a pH which is greater than or equal to 8.5 is maintained.
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- PHARMACOLOGICALLY ACTIVE AMINOALKYLPHENYL COMPOUNDS AND THEIR USE
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Compounds of the general formula: STR1 and physiologically acceptable salts, and hydrates, N-oxides and bioprecursors of such compounds and such salts in whichR 1 and R 2, which may be the same or different, represent hydrogen or lower alkyl, cycloalkyl, aralkyl or lower alkenyl groups, or lower alkyl groups interrupted by an oxygen atom or a group STR2 in which R 4 represents hydrogen or lower alkyl; or R 1 and R 2 may, together with the nitrogen atom to which they are attached form a heterocyclic ring which may contain the hetero functions--O--and STR3 R 3 represents hydrogen, lower alkyl, alkenyl or alkoxyalkyl; X represents--O--,--S--or--CH 2--or STR4 where R 5 is hydrogen or lower alkyl; Y represents =S, =O, =NR 6 or =CHR. sub.7 ;in which R 6 represents hydrogen, nitro, cyano, lower alkyl, aryl, arylsulphonyl or lower alkylsulphonyl; R 7 represents nitro, lower alkylsulphonyl or arylsulphonyl; m is an integer from 2 to 4 inclusive; n is zero, 1 or 2; and Alk denotes a straight or branched alkylene chain of 1 to 6 carbon atoms. The compounds have therapeutic activity.
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- Mitomycin derivatives
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Novel mitomycin derivatives are characterized by a substituent on the C6 -methyl group. The mitomycin derivatives exhibit anti-tumor and antibacterial activity and have low toxicity.
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- Granular cysteamine hydrochloride and method for production thereof
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Molded particles of cysteamine hydrochloride obtained by preparing cysteamine hydrochloride powder having a water content of not more than 1% by weight and compression molding said cysteamine hydrochloride under a pressure of not less than 50 atmospheres, and granules of cysteamine hydrochloride obtained by melting cysteamine hydrochloride powder and cooling and solidifying the resultant molten cysteamine hydrochloride, and manufacture thereof.
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- Synthesis and Insecticidal Activity of Oxazaphospholidines, Oxathiaphospholanes, and Thiazaphospholidines
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Fifty-five new five-membered cyclic organophosphorus compounds including oazaphospholidines, thiazaphospholidines, and oxathiaphospholanes were synthesized, which have substituents at 4- or/and 5-positions besides at the 2-position.The thiazaphospholidines showed the highest insecticidal activity followed by oxathiaphospholanes and oxazaphospholidines.The position preference of substituents in insecticidal activity was most obvious in the oxazaphospholidines.It was preferable for insecticidal activity to have the substituent near the more basic atom: the 4-position for thiazaphospholidine and oxazaphospholidine, the 5-position for oxathiaphospholane, with the exception of 4- or 5-phenyl oxazaphospholidine.
- Wu, Shao-Yong,Hirashima, Akinori,Takeya, Ryuko,Eto, Morifusa
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p. 2911 - 2918
(2007/10/02)
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- INHIBITORS OF HUMAN LEUCOCYTE ELASTASE. PEPTIDES INCORPORATING AN &α-AZANORVALINE RESIDUE OR A THIOMETHYLENE LINKAGE IN PLACE OF A PEPTIDE BOND
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Peptides containing an α-azanorvaline residue at the C-terminus and N- group at the N-terminus have been made as inhibitors of human leucocyte elastase.A number of analogues with an amide bond replaced by a thiomethylene group have also been prepared.The analogues were tested against leucocyte elastase using MeO-Suc-Ala-Ala-Pro-Val-p-nitroanilide as a substrate and the results were obtained as IC50 values.Both types of analogues inhibited the leucocyte elastase; the most potent of these was N--L-valyl-L-prolyl-α-azanorvaline phenyl ester ( 2 ) ( IC50 0.28 μM, Ki 0.02 μM ).
- Dutta, Anand S.,Giles, Michael, B.,Gormley, James J.,Williams, Joseph C.,Kusner, Edward J.
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p. 111 - 120
(2007/10/02)
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- REACTIONS OF AZIRINES WITH SULFUR NUCLEOPHILES. 4. TREATMENT OF 2H-AZIRINE WITH MERCAPTOSUBSTITUTED ACIDS. REACTIONS OF AZIRIDINYL ALKYL SULFIDES WITH CARBOXYLIC ACIDS AND ACYL CHLORIDE DERIVATIVES
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Treatment of 2H-azirines with mercaptosubstituted acids and their derivatives leads to β-ketoamides and 2-aziridinyl alkyl sulfides, respectively. 2-Aziridinyl alkyl sulfides, in turn, react with carboxylic acids to give β-ketoamides and substituted ethanethiol derivatives.Acylation of 2-aziridinyl alkyl sulfides with acyl halides generates a variety of products, depending on the reaction conditions; either products derived from cleavage and isomerization of the aziridinyl ring or (1-acylaziridinyl-2) alkyl sulfides are obtained.
- El'kinson, R.S.,Eremeev, A.V.
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p. 161 - 166
(2007/10/02)
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- Process for producing 2-mercaptoethylamine hydrohalides
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A process for producing 2-mercaptoethylamine hydrohalides of the general formula STR1 wherein R1, R2, R3 and R4 are identical or different, and each represents a hydrogen atom, a lower alkyl group, a hydroxy-substituted lower alkyl group or a phenyl group, and X represents a halogen atom, which comprises reacting a 2-mercaptothiazoline of the general formula STR2 wherein R1, R2, R3 and R4 are as defined above, with a 2-halogenoethylamine hydrohalide of the general formula STR3 wherein R1, R2, R3, R4 and X are as defined above, in the presence of water.
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