- An improved synthesis of the antiulcer drug ranitidine from N-[2-[[[5- (hydroxymethyl)-2-furanyl]-methyl]-thio]-ethyl]-N'-methyl-2-nitro-1,1- ethenediamine
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An improved synthesis of the antiulcer drug ranitidine from N-[2-[[[5- (hydroxymethyl)-2-furanyl]-methyl]-thiol]-ethyl]-N'methyl-2-nitro-1,1- ethenediamine is reported.
- Aasen, Arne Jorgen,Skramstad, Jan
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- New method for synthesizing ranitidine
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The invention discloses a new method for synthesizing ranitidine. The method comprises the steps of synthesizing vinylidene chloride, synthesizing 1, 1-dichloro-2-nitroethylene, carrying out a ring-closing reaction, carrying out a ring-opening reaction in presence of a desiccant, and synthesizing the ranitidine. The method adopts an anhydrous environment in the preparation process of a ring-opening product, thus avoiding the interference with the reaction and the generation of impurities due to the presence of water, reducing the post-treatment work and increasing the utilization rate of the raw materials. The preparation method provided by the invention effectively increases the reaction yield of the ring-opening product, improves the purity of the ring-opening reaction, and reduces the reaction time; therefore, the yield and purity of the product ranitidine are improved, the production cost is lowered, and the method is more beneficial to industrial production.
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Paragraph 0034; 0039-0044; 0047; 0052-0057; 0059; 0064-0069
(2018/12/14)
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- Ranitidine oral preparation for treating new indications of erosive esophagitis
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The invention discloses a ranitidine and a preparation method thereof, as well as a ranitidine preparation, a compound preparation and a preparation method thereof. The ranitidine has a low impurity content, high stability, and the preparation method is simple; the ranitidine preparation and the compound preparation prepared therefrom have high bioavailability and safety. The ranitidine, the ranitidine preparation and the compound preparation provided by the invention can effectively treat and maintain the treatment of erosive esophagitis.
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Paragraph 0240; 0241; 0242; 0243; 0244-0247; 0274; 0287
(2018/11/22)
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- Novel synthesis method for high-stability ranitidine bismuth citrate
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The invention discloses a novel synthesis method for high-stability ranitidine bismuth citrate. The method includes the steps of: 1) preparing a raw material solution; 2) performing a reaction to prepare ranitidine; 3) purifying the ranitidine; 4) performing a salt forming reaction; 5) discolorizing and sterilizing a product; and 6) producing a ranitidine bismuth citrate finish product. The novel synthesis method, through reasonable process design, can increase the quality and stability of ranitidine, thereby improving the pharmacologic property and stability of the ranitidine bismuth citrate. The novel synthesis method is low in raw material cost, has gentle process conditions, is good in controllability and yield, and is suitable for industrial production.
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Paragraph 0016
(2018/01/12)
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- Critical Influence of 5-Hydroxymethylfurfural Aging and Decomposition on the Utility of Biomass Conversion in Organic Synthesis
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Spectral studies revealed the presence of a specific arrangement of 5-hydroxymethylfurfural (5-HMF) molecules in solution as a result of a hydrogen–bonding network, and this arrangement readily facilitates the aging of 5-HMF. Deterioration of the quality of this platform chemical limits its practical applications, especially in synthesis/pharma areas. The model drug Ranitidine (Zantac) was synthesized with only 15 % yield starting from 5-HMF which was isolated and stored as an oil after a biomass conversion process. In contrast, a much higher yield of 65 % was obtained by using 5-HMF isolated in crystalline state from an optimized biomass conversion process. The molecular mechanisms responsible for 5-HMF decomposition in solution were established by NMR and ESI-MS studies. A highly selective synthesis of a 5-HMF derivative from glucose was achieved using a protecting group at O(6) position.
- Galkin, Konstantin I.,Krivodaeva, Elena A.,Romashov, Leonid V.,Zalesskiy, Sergey S.,Kachala, Vadim V.,Burykina, Julia V.,Ananikov, Valentine P.
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p. 8338 - 8342
(2016/07/19)
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- Synthesis of ranitidine (Zantac) from cellulose-derived 5-(chloromethyl)furfural
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The biomass-derived platform chemical 5-(chloromethyl)furfural is converted into the blockbuster antiulcer drug ranitidine (Zantac) in four steps with an overall 68% isolated yield. The Royal Society of Chemistry.
- Mascal, Mark,Dutta, Saikat
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supporting information; experimental part
p. 3101 - 3102
(2011/12/15)
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- ANHYDROUS TABLET OF RANITIDINE HYDROCHLORIDE WITH DOUBLE-LAYER COATING AND ITS COMPOSITION
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The invention concerns an anhydrous tablet containing anhydrous ranitidine hydrochloride, coated by a double-layer coating, its composition and the relevant process of preparation. The anhydrous tablet of the invention is characterized by the direct dry tabletting, without using water, of a mixture consisting of the active ingredient anhydrous ranitidine hydrochloride, in the crystalline form "allomorphous Form 1" having a particular purity and stability, and by a global amount of other excipients and adjuvant substances or inert vehicles less than the weight of the active ingredient. Moreover, the anhydrous tablet of the invention is characterized by a high percentage of disintegrating substance in the tabletting mixture and by a special two-layer coating.
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Page/Page column 7
(2008/06/13)
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- PROCESS FOR PRODUCTION OF ALKANESULFONIC ACID
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The present invention relates to a process for the production of alkanesulfonic acid. More particularly, the present invention relates to a process for the production of alkanesulfonic acid from alkyl mercaptan effluents generated in chemical industries. The process of the invention comprises the oxidation of the entire alkyl mercaptan generated as an effluent in the chemical industries to serve two concomitant purposes: (1) complete removal of obnoxious odour, and (2) value addition by the production of alkanesulfonic acids selectively in quantitative yields.
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- Process for production of alkanesulfonic acid
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The present invention relates to a process for the production of alkanesulfonic acid. More particularly, the present invention relates to a process for the production of alkanesulfonic acid from alkyl mercaptan effluents generated in chemical industries. The process of the invention comprises the oxidation of the entire alkyl mercaptan generated as an effluent in the chemical industries to serve two concomitant purposes: (1) complete removal of obnoxious odour, and (2) value addition by the production of alkanesulfonic acids selectively in quantitative yields.
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- A new method for the synthesis of ranitidine.
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An improved synthesis of the antiulcer drug Ranitidine from an oxazolidine derivative is reported.
- Lipnicka, Urszula,Jasztold-Howorko, Ryszard,Witkiewicz, Krystyna,Machon, Zdzislaw
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p. 121 - 125
(2007/10/03)
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- Processes for preparing ranitidine
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The present invention relates to a novel method for preparing ranitidine and pharmaceutically acceptable salts thereof.
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- Carboxylic acid derivatives
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The invention relates to salts formed between ranitidine and a complex of zinc with a carboxylic acid selected from tartaric acid, citric acid and alkyl citric acids, and to solvates of such salts. The salts and solvates thereof are useful in the treatment of gastro-intestinal disorders, such as peptic ulcer disease and non-ulcer dyspepsia.
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- Preparation of substituted ethenes
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A potassium salt useful in the production of N-substituted-1-alkylthio-2-nitroethenamines is produced by the reaction of the dipotassium salt of nitrodithioacetic acid with certain straight chain alkylamines, thereby converting only one of the KS-groups to an alkylamine group. The resulting monopotassium salt may be alkylated to produce the required N-substituted-1-alkylthio compound which may be reacted with a suitable amine to produce the histamine H2 -antagonist ranitidine.
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- Process for the preparation of a furan derivative
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The invention relates to a process for the preparation of ranitidine of formula (I) STR1 which comprises reacting a thiol of formula (II) STR2 with an alkylating agent of formula (III) STR3 The ethyleneimino derivative of formula (III) is a novel compound.
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- Process for the preparation of a furan derivative
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Ranitidine is prepared by treating an aldehyde of formula (II) STR1 with dimethylamine and a reducing agent which is capable of effecting reductive alkylation to introduce the group Me2 NCH2 -- but which does not reduce the nitroethene group. The reaction is carried out in a suitable solvent, preferably in the presence of an acid or followed by treatment with an acid. Suitable reducing agents include, diborane, aluminium hydride and alkali or alkaline earth metal borohydrides. The aldehyde (II) may be generated in situ from an acetal of formula (III) STR2 where R1 and R2 are both alkyl groups or R1 OCHOR2 forms a cyclic acetal.
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- Intermediates in the preparation of ranitidine
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The invention relates to a process for the preparation of ranitidine of formula (I) STR1 which comprises reacting a thiol of formula (II) STR2 with an alkylating agent of formula (III) STR3 where L is a leaving group, preferably halogen. The invention also relates to novel intermediates, the thiol of formula (II) STR4 in the form of a stable acid addition salt, and the isothiourea of formula (IV) STR5 and stable acid additions salts thereof.
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- Process for the preparation of a furan derivative
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Ranitidine is prepared by reacting a compound of formula (II) STR1 with aziridine. The reaction may be carried out in the absence of a solvent or preferably in the presence of a solvent such as water or an alkanol at elevated temperature.
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- Process for the preparation of a furan derivative
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Ranitidine is prepared by reacting cystamine of formula (II) STR1 either with a nitroethenamine of formula (III) STR2 where L is a leaving group such as alkylthio, e.g. methylthio, or with a compound of formula (IV) STR3 where L is a leaving group as defined above, followed by reaction with methylamine, to give a disulphide of formula (V) STR4 which is then reacted with 5-[(dimethylamino)methyl]-2-furanmethanol under acid conditions.
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- Aminoalkyl furan derivatives
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Compounds of the general formula I: STR1 and physiologically acceptable salts thereof and N-oxides and hydrates, in which R1 and R2 which may be the same or different represent hydrogen, lower alkyl, cycloalkyl, lower alkenyl, aralkyl or lower alkyl interrupted by an oxygen atom or a group STR2 in which R4 represents hydrogen or lower alkyl or R1 and R2 may, together with the nitrogen atom to which they are attached, form a heterocyclic ring which may contain other heteroatoms selected from O and STR3 R3 is hydrogen, lower alkyl, lower alkenyl or alkoxyalkyl; X is --CH2 --, O or S; Y represents = S, = O, = NR5 or = CHR6 ; Alk denotes a straight or branched alkylene chain of 1 to 6 carbon atoms; R5 is H, nitro, cyano, lower alkyl, aryl, alkylsulphonyl, or arylsulphonyl; R6 represents nitro, arylsulphonyl or alkylsulphonyl; M is an integer from 2 to 4; and N is 1 or 2; or when X = S, or --CH2 --, n is zero, 1 or 2. These compounds have H2 -antagonist activity. Intermediates in the production thereof are also provided.
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