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Method for preparing 2-methyl-8-aminoquinoline from o-nitrophenol

A technology of aminoquinoline and o-nitrophenol, applied in the direction of organic chemistry, can solve the problem of difficult preparation of 2-methyl-8-aminoquinoline, difficult amino substitution reaction, separation and purification of 2-methyl-8- Solve the problems of nitroquinoline, etc., and achieve the effect of novel preparation process

Inactive Publication Date: 2012-09-19
HUNAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The Chinese patent describes that 2-methyl-8-aminoquinoline can be obtained by hydrogenation reduction of 2-methyl-8-nitroquinoline (ZL200510094326.6); but the nitration of 2-methylquinoline is mainly 2- A mixture of methyl-5-nitroquinoline and 2-methyl-8-nitroquinoline; it is difficult to separate and purify 2-methyl-8-nitroquinoline (EP 0132714; Chemical World, 2009, (2 ), 122-126; Heterocyclic Chemistry, Science Press, 2004, 134)
But the amino substitution reaction of follow-up 2-methyl-8-chloroquinoline is difficult to carry out, it is difficult to prepare 2-methyl-8-aminoquinoline

Method used

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  • Method for preparing 2-methyl-8-aminoquinoline from o-nitrophenol
  • Method for preparing 2-methyl-8-aminoquinoline from o-nitrophenol
  • Method for preparing 2-methyl-8-aminoquinoline from o-nitrophenol

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Preparation of o-aminophenol

[0038]

[0039] O-nitrophenol was catalytically hydrogenated (Pd / C, H 2 ) or chemical reduction (Na 2 S) make o-aminophenol.

Embodiment 2

[0041] Preparation of 2-methyl-8-hydroxyquinoline

[0042]

[0043] 33.0g (0.3mol) o-aminophenol 150mL 18% HCl stirred and refluxed; 0.5h dropwise added 14.0g (0.1mol) o-nitrophenol and 42.0mL (0.4mol) crotonaldehyde solution, refluxed for 2h, cooled, neutralized with ammonia water, Extract with toluene (100mL×4), dry over anhydrous sodium sulfate, and rotate the solvent to obtain a black solid, distill under reduced pressure, collect fractions at 149~155℃ / 246Pa to obtain 2-methyl-8-hydroxyquinoline, mp 71~ 72°C, yield ≥ 85%. MS (m / z): 159 (M + ). 1 H NMR (CDCl 3 , 400MHz) δ: 2.71 (s, 3H, CH 3 ), 7.13(d, J=7.2Hz, 1H, quinoline ring 7-H), 7.22~7.30(m, 2H, quinoline ring 3, 6-H), 7.32~7.41(m, 1H, quinoline ring 5-H), 8.00 (d, J = 8.4 Hz, 1H, quinoline ring 4-H).

Embodiment 3

[0045] Preparation of 2-methyl-8-aminoquinoline

[0046]

[0047] 2-methyl-8-hydroxyquinoline 31.8g (0.20mol), ammonium chloride (0.10mol), cobalt chloride (0.02mol), 22-28% ammonia water 120mL, filled with N 2 Gas, heated to 300-320°C, pressure 1.8-2.2MPa, pressure-holding and heat-retaining reaction for 4-6h; after the reaction, the reaction solution was extracted with toluene, the organic layer was collected, dried, and the solvent was recovered to obtain a dark gray solid, which was distilled under reduced pressure 2-methyl-8-aminoquinoline is obtained with a yield of ≥70%. mp: 56-58°C. 1 H NMR (CDCl 3 , 400MHz) δ: 2.70 (s, 3H, CH 3 ), 4.97 (brs, 2H, NH 2 ), 6.89 (d, J=7.2Hz, 1H, quinoline ring), 7.10 (d, J=8.0, 1H, quinoline ring), 7.24 (m, 2H, quinoline ring), 7.93 (d, J= 8.0, 1H, quinoline ring).

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Abstract

The invention discloses a preparation method of 2-methyl-8-aminoquinoline. The preparation method is characterized in that the 2-methyl-8-aminoquinoline is prepared from o-nitrophenol through a process line of reduction, cyclization and amino substitution. An oxidant is selected from one or more of the o-nitrophenol, ammonium ceric nitrate, vanadic acid and iron oxide, and a catalyst is selected from ammonium chloride-cobalt chloride, palladium-aluminum trioxide or aluminum trioxide-silicon dioxide.

Description

technical field [0001] The invention relates to a preparation method of a fine chemical intermediate, in particular to a method for preparing 2-methyl-8-aminoquinoline from o-nitrophenol. Background technique [0002] 2-methyl-8-aminoquinaldine (also known as 8-aminoquinaldine) is an important intermediate in organic synthesis, mainly used in dye production, and can also be used in the preparation of pharmaceutical intermediates (CN1918244, CN1763013, EP0463477A1, US3622583 , US5106980, US5030717). [0003] The Chinese patent describes that 2-methyl-8-aminoquinoline can be obtained by hydrogenation reduction of 2-methyl-8-nitroquinoline (ZL200510094326.6); but the nitration of 2-methylquinoline is mainly 2- A mixture of methyl-5-nitroquinoline and 2-methyl-8-nitroquinoline; it is difficult to separate and purify 2-methyl-8-nitroquinoline (EP 0132714; Chemical World, 2009, (2 ), 122-126; Heterocyclic Chemistry, Science Press, 2004, 134). [0004] [0005] A Chinese pate...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D215/40
Inventor 胡艾希李国希吴天泉沈芳叶姣
Owner HUNAN UNIV
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