# US 2014/0197024 A1 · Microwave induced single step green synthesis of some novel 2-aryl aldehydes and their analogues

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- Number: US 2014/0197024 A1
- Document ID: US20140197024A1
- Status: Published application
- Kind: A1
- Application number: 14/156,862
- Filed: 2014-01-16
- Published: 2014-07-17
- Earliest claimed: 2009-02-25
- Assignees: Council of Scientific and Industrial Research
- Applicants: Council of Scientific & Industrial Research
- Inventors: Arun Kumar SINHA; Abhishek SHARMA; Rakesh KUMAR; Naina SHARMA
- Web page: https://patentgrep.com/patent/US20140197024A1

## CPC

- C07C 45/28: of CHx-moieties
- C07C 45/30: with halogen containing compounds, e.g. hypohalogenation
- C07C 249/16: of hydrazones
- C07C 311/49: to nitrogen atoms
- C07D 317/54: Radicals substituted by oxygen atoms
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)

## Abstract

A microwave-induced process for the preparation of 2-aryl and 2,2-diaryl aldehydes and analogues wherein halohydrin formation and subsequent rearrangement to 2-aryl aldehydes from corresponding aryl alkanols occurs without formation of an intermediate epoxide or use of transition metal catalysts or lewis acids/bases.

## Claims

### Claim 1

(canceled)

### Claim 2

(canceled)

### Claim 3

A microwave induced process for the synthesis of substituted 2-aryl aldehydes and analogues of general formula 1
R′ is selected from the group consisting of CH3, C2H5, C6H5 and C6H4-(4-OCH3);
X is O or N—NH—SO2—C6H4—CH3;
R1 to R5 are selected from the group consisting of H, OH, OCH3, C6H5, and a halogen atom, or R2+R3 together represent a —(CH═CH—CH═CH)— group or a —(O—CH2—O)— group;
comprising the steps of:
a) reacting a substituted aryl alkene and an N-halosuccinimide and a phase transfer catalyst in a solvent under microwave irradiation to form a halohydrin which rearranges to a 2-aryl aldehyde in one pot without the formation of an intermediate epoxide;
b) transferring the reaction mixture of step (a) into ice cold water and extracting with an organic solvent;
c) washing the organic solution of step (b) with aqueous sodium thiosulphate, brine and water;
d) drying the organic layer of step (c) over anhydrous sodium sulphate, filtering and evaporating to dryness to completely remove the solvent to obtain a residue; and
e) purifying the residue of step (d) on silica gel to obtain the substituted 2-aryl aldehydes of general formula 1.

### Claim 4 (depends on 3)

The process as claimed in claim 3, wherein the N-halosuccinimide is selected from the group consisting of N-bromosuccinimide, N-iodosuccinimide, N-chlorosuccinimide and combinations thereof.

### Claim 5 (depends on 3)

The process as claimed in claim 3, wherein the solvent in step (a) is either water or a mixture of water-organic solvent wherein the organic solvent is selected from the group consisting of dimethyl sulphoxide, dioxane, dimethylformamide, dimethoxyethane, ionic liquids and combinations thereof.

### Claim 6 (depends on 3)

The process as claimed in claim 3, wherein the organic solvent used in step (b) is ethyl acetate.

### Claim 7 (depends on 3)

The process as claimed in claim 3, wherein the phase transfer catalyst is selected from the group consisting of Cetyltrimethyl Ammonium Bromide, N-hexyl ammonium chloride and chiral phase transfer catalysts.

### Claim 8

(canceled)

### Claim 9 (depends on 3)

The process as claimed in claim 3, wherein said microwave irradiation is a monomode or a multimode microwave irradiation.

### Claim 10

(canceled)

### Claim 11 (depends on 3)

The process as claimed in claim 3, wherein the mole ratio of substituted arylalkene to N-halosuccinimide is 1:1 to 1:3 moles.

### Claim 12 (depends on 5)

The process as claimed in claim 5, wherein the volume ratio of water to solvent is in the range of 1:4 to 4:1.

### Claim 13 (depends on 3)

The process as claimed in claim 3, wherein the mole ratio of substituted arylalkene to phase transfer catalyst is 1:0.1 to 1:0.5 moles.

### Claim 14

(canceled)