Unlock instant, AI-driven research and patent intelligence for your innovation.

A method for preparing 3,4-dihydrobenzo[b][1,4]oxazine derivatives

A technology of dihydrobenzene and oxazine, applied in the field of preparing 3,4-dihydrobenzo[b][1,4]oxazine derivatives, which can solve the problems of high metal catalyst price and difficult removal of metal residues, etc. Achieve the effect of large industrialization potential, high reactivity, and wide range of substrates

Active Publication Date: 2017-11-24
INST OF CHEM CHINESE ACAD OF SCI
View PDF1 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The reported synthetic methods have certain defects, the metal catalysts used are expensive and the metal residues are difficult to remove

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A method for preparing 3,4-dihydrobenzo[b][1,4]oxazine derivatives
  • A method for preparing 3,4-dihydrobenzo[b][1,4]oxazine derivatives
  • A method for preparing 3,4-dihydrobenzo[b][1,4]oxazine derivatives

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0081] The synthesis of embodiment 1,3-(2-thiophene)-3,4-dihydrobenzo[b][1,4]oxazine (see structural formula I-a)

[0082] according to figure 1 Shown synthetic route prepares the compound shown in formula I-a, concrete operation is as follows:

[0083]In the glove box, 3-(2-thiophene)benzo[b][1,4]oxazine (shown in formula II-a) (0.086g, 0.4mmol), tris(pentafluoro phenyl)borane (0.0051 g, 0.01 mmol), and 0.2 mL of toluene. Put the reaction sleeve into the autoclave and tighten the autoclave, fill it with hydrogen gas at 20bar, and react at 50°C for 6h; after the reaction is completed, remove the solvent, and the conversion rate is >99% as measured by NMR. The specific conditions are as follows: The specification of the analysis column is 20cm in diameter × 200cm in height, the filler is 200-300 mesh silica gel, and the column is packed with petroleum ether. The eluent is a mixture of ethyl acetate and petroleum ether with a volume ratio of 1:10. The flow rate is 10mL / min, e...

Embodiment 2

[0086] The synthesis of embodiment 2,3-(1-naphthyl)-3,4-dihydrobenzo[b][1,4]oxazine (see structural formula I-b)

[0087] according to figure 2 The shown synthetic route prepares the compound shown in formula I-b, concrete operations are as follows:

[0088] In the glove box, successively add 3-(1-naphthyl)benzo[b][1,4]oxazine (shown in formula II-b) (0.104g, 0.4mmol), three (five Fluorophenyl)borane (0.0051 g, 0.01 mmol), and 0.2 mL of toluene. Put the reaction sleeve into the autoclave and tighten the autoclave, fill it with hydrogen gas at 20bar, and react at 50°C for 6h; The specification of the analysis column is 20cm in diameter × 200cm in height, the filler is 200-300 mesh silica gel, and the column is packed with petroleum ether. The eluent is a mixture of ethyl acetate and petroleum ether with a volume ratio of 1:10. The flow rate is 10mL / min, eluting with 10 times column volume of eluent, collecting the eluate of the 9th column volume, removing the solvent to obt...

Embodiment 3

[0091] Embodiment 3, the synthesis of 3-(3,4-dichlorophenyl)-3,4-dihydrobenzo[b][1,4]oxazine (see structural formula I-c)

[0092] according to image 3 The shown synthetic route prepares the compound shown in formula I-c, concrete operations are as follows:

[0093] In the glove box, sequentially add 3-(3,4-dichlorophenyl)benzo[b][1,4]oxazine (shown in formula II-c) (0.111g, 0.4mmol) to the sleeve , tris(pentafluorophenyl)borane (0.0051 g, 0.01 mmol), and 0.2 mL of toluene. Put the reaction sleeve into the autoclave and tighten the autoclave, fill it with hydrogen gas at 20bar, and react at 50°C for 6h; after the reaction is completed, remove the solvent, and the conversion rate is >99% as measured by NMR. The specific conditions are as follows: The specification of the analysis column is 20cm in diameter × 200cm in height, the filler is 200-300 mesh silica gel, and the column is packed with petroleum ether. The eluent is a mixture of ethyl acetate and petroleum ether with ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention provides a method for preparing 3,4-dihydrobenzo[b][1,4]oxazine derivatives. The method comprises the following step: carrying out reduction reaction on [b][1,4]oxazines in the presence of hydrogen gas by using B(C6F5)3 as a catalyst to obtain the mixture containing the 3,4-dihydrobenzo[b][1,4]oxazines disclosed as Formula I. Benzo[b][1,4]oxazines in different structures are used as a substrate to synthesize the benzo[b][1,4]oxazines at high yield by using the B(C6F5)3 as the catalyst. The method has the advantages of cheap and accessible raw materials, high reaction activity, no participation of transition metals and wide substrate application range, and has huge industrialization potential.

Description

technical field [0001] The invention belongs to the field of organic synthesis, in particular to a method for preparing 3,4-dihydrobenzo[b][1,4]oxazine derivatives. Background technique [0002] The 3,4-dihydrobenzo[b][1,4]oxazines represented by formula I play a very important role in organic synthesis and have potential biological activities. This type of compound skeleton widely exists in a variety of natural products with biological activity, among which levofloxacin derived from 3,4-dihydrobenzo[b][1,4]oxazine compounds is a mature class of commercially available drugs . [0003] [0004] In the formula I, R 1 Any one of methyl, chlorine and bromine; R 2 Any one selected from naphthyl, phenyl, substituted phenyl and thienyl; [0005] The current method for preparing 3,4-dihydrobenzo[b][1,4]oxazine in organic synthesis is mainly to use transition metals to catalyze the hydrogenation of benzo[b][1,4]oxazine derivatives with hydrogen. The reaction is obtained, and ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C07D265/36C07D413/04
CPCC07D265/36C07D413/04
Inventor 杜海峰魏思敏
Owner INST OF CHEM CHINESE ACAD OF SCI