2-(n-morpholin)-4-methylpyridin as inhibitors of acid corrosion of steel
(57) Abstract:The invention relates to new chemical compound is 2-(N-morpholin)-4-methylpyridine, which can be used as inhibitors of acid corrosion of steel by acid treatment of wells or refineries. table 1. The present invention relates to new chemical compounds, specifically, 2-(N-morpholin)-4-methylpyridine General formula (1), which can be used as inhibitors of acid corrosion of steel.< / BR>Corrosion of steel equipment industrial facilities during their contact with aqueous solutions of mineral acids brings significant damage to the national economy. To date, the most effective way to protect steel equipment industrial facilities is the use of inhibitors of acid corrosion of steel.A well-known inhibitor of acid corrosion of steel - catopen B-300 /, Directory "corrosion Inhibitors", M.: 1975, S. 61/, which at a concentration of 0.5 weight. % 20% HCl solution at 20oC protects the steel from corrosion by 97%. The main disadvantage of the known inhibitor is relatively large (0.5 wt.%) consumption, making it unprofitable for W is iridin /, A. Altsybeeva, S. Levin. The corrosion inhibitors of metals. Ed. "Chemistry", L., 1968, S. 20/ protects the steel from corrosion in a 10% solution of hydrochloric acid at 20oC 71.4% (at a concentration of pyridine 0.4%). The disadvantages of the known inhibitor are:
the relatively low degree of protection of steel from corrosion (~71%),
the relatively high consumption of the inhibitor,
high toxicity and volatility of pyridine, impeding its large scale application.The aim of the invention is the identification of new derivatives of pyridine, allowing for their use as inhibitors of acid corrosion to give the steel an increased protective effect.This goal is achieved by the synthesis of 2-(N-morpholin)-4-methylpyridine of formula (1).The proposed connection is obtained by mixing in the atmosphere of inert gas equimolar quantities motoline c ethylmagnesium (EtMgBr) in tetrahydrofuran (THF), followed by stirring at a temperature of ~ 40oC for 2 h, the Reaction is accompanied by release of ethane. The reaction mass is cooled to ~ 0oC add a catalytic amount (2-5 mol.% in relation to the morpholine) palladium catalyst (Pd[PPh3]4and Aquitaine in relation to the mos morpholyl)-4-methylpyridin with the release of 75-94% scheme:
< / BR>Testing the protective effects of 2-(N-morpholin)-4-methylpyridine as a corrosion inhibitor for carbon steel in acidic media was carried out in laboratory conditions. As working environments were used 15% solution of HCl and 20% solution of H2SO4.Pre-treated for corrosion testing samples of the steel ARTICLE. 3 GOST 380-71 put into the working environment for a certain time () at 20oC. after the exposure time of the samples is subjected to appropriate processing, weigh up to 0.0001, the corrosion Rate (), the degree of protection of steel (Z) inhibitor of metal corrosion is determined in accordance with formulas (2) and (3).(2)
where m is the mass change, g;
S - area of the sample, m2;
- test time, h;
where1the corrosion rate in the absence of inhibitor;
2- speed corrosion-inhibited environment.As shown by the test results, the proposed inhibitor exhibits a high inhibitory effect 93.1-95.6% when the concentration of the inhibitor 0.05-0.1 wt%, whereas pyridine at a concentration of 0.4 wt.% protects the steel from corrosion only at 71.4%. To obtain equal effect of protection is necessary to spend Katarina B-300 is a (93.1-95.6%) with a low consumption of reagent (0.05-0.1 wt.%).The proposed inhibitor of acid corrosion of steel involves the possibility of its application in industries where the contacting metals with aqueous solutions of mineral acids, in particular, when the acid treatment of wells or refineries.Synthesis of 2-(N-morpholin)-4-methylpyridine is illustrated by an example.Example. To 10 mmol EtMgBr in THF solution in an argon atmosphere, add 10 mmol of the research and stirred for 2 h at a temperature of ~40oC. the Reaction is accompanied by release of ethane. Next, at a temperature of ~ 0oC added 0.3 mmol of Pd(PPh3)4and 10 mmol of 2-bromo-4-methylpyridine, stirred at a temperature of ~ 40oC 8 hours (total time 10 hours). The reaction mass is cooled to ~20oC add a saturated solution of NH4Cl, the organic layer is extracted with ether, dried with MgSO4. Get 2-(N-morpholin)-4-methylpyridin with the release of 83%. T Kip. 98-99oC (2 mm RT.cent.), nD201,5682, IR spectrum (V, cm-1): 1245, 1125, 780, 750. Range of the MRP , M. D.): 2.29 (3H, CH3), 3.58 - 3.66 m (4H, CH2, N), 3.73 - 3.95 m (4H, CH2O), 6.80 - 8.57 (m, 3H, pyridine) M+178.Data illustrating the protective properties of 2-(N-morpholin)-4-methylpyridine, shown in TA is Tali.
< / BR>where X denotes O, S, NH or NA;
Y represents substituted with R2aziridinyl, azetidinone, pyrolidine, piperidinyl, hexahydroazepin or pieperazinove the rest;
R1indicatesor< / BR>R2represents CrH2r-COOR3;
R3denotes H, A or Ar;
A denotes alkyl with 1-6 C-atoms;
B denotes H, a, cycloalkyl with 3-7 C atoms, Ar-CkH2kor aydinbey the rest;
Ar denotes unsubstituted or mono - or twice substituted with A, Cl, Br, I, NO2, CN, OA, OH, NH2, NHA and/or NA2phenyl or benzyl residue;
"k" denotes 1, 2, 3 or 4;
"m" and "r" each, independently of one another, denote 0, 1, 2, 3 or 4; and
"n" represents 2, 3 or 4,
and their physiologically acceptable salts
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to a new method for preparing 5-(4-fluorophenyl)-1-[2-((2R,4R)-4-hydroxy-6-oxotetrahydropyran-2-yl)ethyl]-2-isopropyl-4-phenyl-1H-pyrrol-3-carboxylic acid phenylamide that involves conversion of methylcyano acetate to the end compound for 8 or less stages. Also, invention relates to value intermediate compounds that are synthesized as result of realization of above indicated stages of the claimed method. 5-(4-Fluorophenyl)-1-[2-((2R,4R)-4-hydroxy-6-oxotetrahydropyran-2-yl)ethyl]-2-isopropyl-4-phenyl-1H-pyrrol-3-carboxylic acid phenylamide is a value intermediate compound used in synthesis of the drug atorvastatin calcium that is used as hypolipidemic and/or hypocholesterolemic agent. Proposed method allows avoiding usage of expensive chiral parent substances and to reduce the synthesis process time.
EFFECT: improved preparing method.
12 cl, 3 ex