99464-81-0Relevant articles and documents
A Simple Conversion of 1-Chloroethyl Carbonates to Fluoroformates: Value in the Preparation of Tertiary Alkyl Fluoroformates
Dang, Vu Anh,Olofson, R. A.,Wolf, Patrick R.,Piteau, Marc D.,Senet, Jean-Pierre G.
, p. 1847 - 1851 (1990)
When the economical and easily available 1-chloroalkyl carbonates (RCHClOCO2R') are heated neat or in solution with KF in the pesence of 18-crown-6 catalyst, they fragment to aldehydes (RCHO) and fluoroformates (FCO2R').If the system is evacuated during reaction and either or both products are removed as formed, then the process is driven to completion and fluoroformates are isolated in good yield.The new methodology (which exemplifies an unusual conversion of an ester to an acid halide) is especially valuable in the synthesis of important tertiary alkyl fluoroformates and benzyl fluoroformate (with R as CH3 in the carbonate): tert-butyl fluoroformate (BOC-F, 84percent yield), tert-amyl fluoroformate (83percent), 1-adamantyl fluoroformate (76percent), benzyl fluoroformate (60percent).Boc-F previously has been recommended as a superior reagent for the preparation of Boc-amino acids, but earlier routes to this reagent have been expensive and impractical.When R in the carbonate reactant is Cl3C, the reaction proceeds cleanly without the 18-crown-6 catalyst (Boc-F in 79percent yield).This latter variation is most useful on a small industrial scale.
BENZIMIDAZOLE COMPOUND, PROCESS FOR PRODUCING THE SAME, AND USE THEREOF
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Page 30, (2010/02/07)
The present invention relates to a compound represented by the following formula wherein each symbol is as defined in the specification, or a salt thereof, which has superior stability to acid and which is a prodrug of 2-[[[3-methyl-4-(2,2,2-trifluoroethoxy)-2-pyridyl]methyl]sulfinyl]-1H-benzimidazole. This compound (1) shows a superior anti-ulcer activity, a gastric acid secretion-suppressive action, a mucosa-protecting action, an anti-Helicobacter pylori action and the like in living organisms, (2) shows low toxicity, (3) shows superior stability to acid (which obviates the need to formulate an enteric-coated preparation, thereby lowering the cost, and reduces the size of preparation to facilitate swallowing for patients having difficulty in swallowing), (4) shows faster absorption than enteric-coated preparations (rapid expression of gastric acid secretion-suppressive action), and (5) is sustainable.
Process for the preparation of carbamates, thiocarbamates and ureas
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, (2008/06/13)
The invention relates to a process for preparing carbamic acid derivatives of formula: STR1 in which R1 or R2 denotes a hydrogen atom or a substituted or unsubstituted, saturated or unsaturated aliphatic, cycloaliphatic or heterocyclic radical, or R1 and R2 together form a ring, and Y denotes OR, SR, STR2 groups, R being a substituted or unsubstituted, saturated or unsaturated aliphatic or cycloaliphatic radical, or a substituted or unsubstituted aromatic radical, R3 and R4 denote a hydrogen atom or an aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic radical or together form a ring, and R6 and R7 denote a saturated or unsaturated, substituted or unsubstituted aliphatic or cycloaliphatic radical, a hydrogen atom, an alkylthio radical or an alkyloxy radical. According to the process, a compound of formula STR3 is reacted with an α-halogenated derivative of formula STR4 at a temperature of -5° to 150° C. in the presence of an acceptor for hydrohalic acid. The carbamates, thiocarbamates or ureas obtained are very useful, especially as pesticides.
