|Title of Invention||
PROCESS FOR SEPARATION OF PARA - NITROCHLOROBENZENE AND META - NITROCHLOROBENZENE
|Abstract||The present invention relates to process for separation of para-nitrochlorobenzene and meta-nitrochlorobenzene comprising two steps (a) reaction of sodium methoxide with the mixture of para-nitrochlorobenzene and meta-nitrochlorobenzene to form para-nitroanisole and un-reacted meta-nitrochlorobenzene and (b) distillation under vacuum to separate both components. In this process expensive crystallization and distillation equipments are not required, less time and energy consuming and easy.|
|Full Text||FORM 2
THE PATENT ACT 1970
(39 of 1970)
The Patents Rules, 2003
(See section 10 and rule 13)
1. TITLE OF THE INVENTION
PROCESS FOR SEPARATION OF PARA-NITROCHLOROBENZENE AND META-NITROCHLOROBENZENE
2. APPLICANT (S)
(a) NAME: Shah Dipakkumar Bhanuchandra
(b)NATIONALITY: an Indian
(c) ADDRESS: 901, Neptune Tower,
3. PREMABLE TO THE DESCRIPTION
The following specification describes the invention.
The following specification particularly describes the invention and the manner in which it is to be performed.
The present invention relates to process for separation of para-nitrochlorobenzene and meta-nitrochlorobenzene.
In the present invention separation of para-nitrochlorobenzene and meta-nitrochlorobenzene is done in two steps (a) reaction of sodium methoxide with the mixture of para-nitrochlorobenzene and meta-nitrochlorobenzene to form para-nitroanisole and un-reacted meta-nitrochlorobenzene and (b) distillation under vacuum to separate both components.
Background of the Invention
p-nitrochlorobenzene and o-nitrochlorobenzene is starting raw material for many of dyes, agrochemical and pharmaceutical products. So the production of p-nitrochlorobenzene and o-nitrochlorobenzene is required in huge quantity
p-nitrochlorobenzene and o-nitrochlorobenzene is produced by nitration of chlorobenzene. During nitration of chlorobenzene, mixture of p-nitrochlorobenzene, o-nitrochlorobenzene and m-nitro chloro benzene is formed. The main product is p-nitrochlorobenzene and o-nitrochlorobenzene. But the formation of m-nitrochlorobenzene cannot be eliminated. The pure o-nitrochlorobenzene is separated out by distillation, but the separation of p-nitrochlorobenzene is difficult as very close boiling point between p-nitrochlorobenzene and m-nitrochlorobenzene. The major part of p-nitrochlorobenzene is separated by distillation followed by crystallization.. Gradually the concentration of m-nitrochlorobenzene increases. After reaching some concentration of m-nitrochlorobenzene, it is very difficult to separate out
both component The separation of p-nitrochlorobenzene and m-nitrochlorobenzene has always been difficult as will be better understood by reference to the physical properties of the p-nitrochlorobenzene and m-nitrochlorobenzene.
Melting Point (°C) 46.0 82.0
Boiling Point (°C) at 200 Torr pressure. 189.0 191.0
Thus mixture of p-nitrochlorobenzene and m-nitrochlorobenzene is generated during manufacturing of p-nitrochlorobenzene and o-nitrochlorobenzene.
US2700060 disclosed a process for separating a mixture of o-nitrochlorobenzene and p-nitrochlorobenzene where the mixture is heated about 175 °C to 205 °C in presence of an excess of aniline until reaction is complete and separating the p-nitrochlorobenzene from the reaction product, 2-nitrodiphenyl-amine by distillation.
JP5 8029746 described separation and purification of isomers of halobenzenenitro compound in which precipitation of raw crystals of an isomer reaction mixture is obtained by nitrating a halobenzene through a combination of specific process without using particular crystallizer and an organic solvent.
GB1322020 described a process for the separation of an isomer mixture o the nitro, chloro, or nitrochlorobenzene or toluene series which comprises cooling a melt of the isomer mixture to obtain a crystal mass consisting of one isomer and a substantially eutectic residual melt, separating the crystal mass for the melt by filtration or centrifugation and purifying the crystal mass by pressing.
GB 1477419 disclosed an apparatus for separating mixture of components having similar boiling points under vacuum condition. The separable mixtures of isomenrs are nitrotoluenes, nitrochlorobenzene, nitrodichlorobenzenes, chloronitrotouene, polychlorobenzene, mitroxylenes, chlorotoluenes, cresols, polychlorodiphenyls, toluidines.
GB 2480 described simultaneously manufacturing and production of pure orthonitrochlorobenzene and pure paranitnchlorobenzene by submitting to fractional distillation under atmospheric pressure or in vacuum.
US3832410 & US3880942 described a process for separating the isomers of nitro and halo-substituted aromatic compounds in a liquid isomeric mixture by surface crystallization from the melt, wherein the isomeric mixture is cooled until crystals form on a cooling surface, the improvement comprising conducting the surface crystallization on a cooling surface of glass/polytetrafluroethylene.
This mixture m-nitrochlorobenzene & p-nitrochlorobenzene is headache for the entire nitro chloro benzene manufacturer. From the worldwide manufacturer, some of sale out this mixture at very low price as separation require big
investment to process and it is time consuming, energy consuming and huge inventory remain in-process.
All above method are costly, time and energy consuming and difficult so there is a need of method which is cheaper, quick and easy.
Objects of the Invention:
The main object of the present invention is to separate meta-nitrochlorobenzene and produce valuable intermediate p-nitroanisole in a cheaper way, in which expensive crystallization and distillation equipments are not required.
A further object of the current invention is to develop a technology which is less time and energy consuming as p-nitroanisole and m-nitrochlorobenzene is easily separate out by simple distillation under vacuum due to wide boiling point difference.
Another object of the invention is that the products of this invention are not a mixture of m-nitroanisole and p-nitroanisole as one might expect. Under the proper condition of reaction, only p-nitrochlorobenzene reacts with sodium methoxide and formed p-nitroanisole and m-nitrochlorobenzene remain as it is.
Summary Of The Invention:
In the present invention separation of para-nitrochlorobenzene and meta-nitrochlorobenzene is done in two steps (a) reaction of sodium methoxide with the mixture of para-nitrochlorobenzene and meta-nitrochlorobenzene to form para-
nitroanisole and un-reacted meta-nitrochlorobenzene and (b) distillation under vacuum to separate para-nitroanisole and un-reacted meta-nitrochlorobenzene. Detailed Description:
The nature of the invention and the manner in which it is to be performed is clearly described in the specification. The invention has various components and they are clearly described in the following pages of complete specification.
In the present invention sodium methoxide is used. Methanol reacts with sodium hydroxide under proper condition, formed sodium methoxide. Sodium methoxide remain in dissolve condition in excess methanol.
CH3OH + NaOH ► CH3ONa + H20
Methanol Sodium Sodium
The process for separation of para-nitrochlorobenzene and meta-nitrochlorobenzene comprising:
(i) Sodium methoxide is reacted with mixture of para-nitrochlorobenzene and meta-nitrochlorobenzene under proper condition.
(ii) p-nitroanisole is formed and m-nitrochlorobenzene remained as it is.
(iii) p-nitroanisole and m-nitrochlorobenzene are separated out by simple distillation under vacuum.
p-nitro chloro m-nitro chloro p-nitro anisole m-nitro chloro
benzene benzene benzene
The above reaction is done at 80 ° C - 180 ° C. More preferable temperature is 100° C - 180 °C. The mixture is heated for 4 - 8 hours.
The invention is illustrated more in detail in the following example. The examples describe and demonstrate embodiments within the scope of the present invention. These examples are given solely for the purpose of illustration and are not to be construed as limitations of the present invention, as many variations thereof are possible without departing from the spirit and scope.
Step 1:- Preparation of Sodium Methoxide
1000-2000 gm of methanol is taken in 5 liter 4 necked RBF on hot plate or in heating mental. It is to be equipped with condenser.
Water circulation is started in condenser.
150 gm sodium hydroxide (caustic soda) is gradually added in methanol at the temperature range of 80 °C - 130°C for 3 - 4 hours under reflux.
Sodium hydroxide should get reacted completely.
Sodium methoxide remains in dissolve condition in excess methanol.
Step 2:- Reaction of mixture - para-nitrochlorobenzene and meta-nitrochlorobenzene with sodium methoxide.
1100 gm mixture of p-nitrochlorobenzene and m-nitrochlorobenzene is gradually added in the solution of sodium methoxide under reflux at temperature range of 80°C-180°C.
The reaction mass is maintained under reflux at temperature range of 80°C -180°C for 4-8 hours.
p-nitrochlorobenzene should get reacted completely.
The formation of one more isomer is around 02 - 15% which having high boiling point. Separation:
Excess methanol is separated out in fractional distillation column.
The reaction mass is washed/neutralized.
The three components (p-nitroanisole, m-nitrochlorobenzene and other isomers) are separated out by fractional distillation column under vacuum.
Further more, there is some water content in methanol as the water is liberated during the formation of sodium methoxide
This water is separated out from the methanol by fractional distillation column at atmospheric pressure before reuse for the formation of sodium methoxide.
1. The process for separation of para-nitrochlorobenzene and meta-nitrochlorobenzene comprising:
(a) reacting sodium methoxide with mixture of para-nitrochlorobenzene and meta-nitrochlorobenzene to form p-nitroanisole and leaving m-nitrochlorobenzene unreacted.
(b) separating p-nitroanisole and m-nitrochlorobenzene by simple distillation under vacuum.
2. A process as claimed in claim 1 step (a) wherein temperature is 80 ° C - 180 ° C.
3. A process as claimed in claim 2 wherein more preferably temperature is 100° C -180 "C.
4. A process as claimed in claim 1 step (a) wherein mixture is heated for 4 - 8 hours.
5. The process for separation of para-nitrochlorobenzene and meta-nitrochlorobenzene substantially as described herein before and with reference to the foregoing examples.
Dated this 13th day of October 2007.
The present invention relates to process for separation of para-nitrochlorobenzene and meta-nitrochlorobenzene comprising two steps (a) reaction of sodium methoxide with the mixture of para-nitrochlorobenzene and meta-nitrochlorobenzene to form para-nitroanisole and un-reacted meta-nitrochlorobenzene and (b) distillation under vacuum to separate both components. In this process expensive crystallization and distillation equipments are not required, less time and energy consuming and easy.
|Indian Patent Application Number||2054/MUM/2007|
|PG Journal Number||14/2011|
|Date of Filing||15-Oct-2007|
|Name of Patentee||SHAH DIPAKKUMAR BHANUCHANDRA|
|Applicant Address||901, NEPTUNE TOWER, ASOPALAV COMPLEX, CHHARWADA ROAD, VAPI-396191,|
|PCT International Classification Number||C07C205/12|
|PCT International Application Number||N/A|
|PCT International Filing date|