FORM 2
THE PATENT ACT 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)

1. TITLE OF THE INVENTION
PROCESS FOR PREPARATION OF 1, 2, 4 TRIAZOLE WITH
MINIMUM FORMATION OF 4-AMINO 1, 2, 4 TRIAZOLE

2. APPLICANT (S)
(a) NAME: Shyamal Organics Pvt. Ltd.
(b)NATIONALITY: an Indian Company
(c) ADDRESS: Plot No. 75/2, ‘J’ Type Area,
Phase – I, GIDC, Estate,
Vapi – 396 195.
Gujarat State, India.

3. PREMABLE TO THE DESCRIPTION

PROVISIONAL

The following specification describes the invention.
 COMPLETE

The following specification particularly describes the invention and the manner in which it is to be performed.

The present invention relates process for preparation of 1, 2, 4 triazole with minimum formation of 4-amino 1, 2, 4 triazole.
Background of the Invention:
1,2,4-Triazole is one of a pair of isomeric chemical compounds with molecular formula C2H3N3, called triazoles, which have a five-membered ring of two carbon atoms and three nitrogen atoms. 1,2,4-Triazole is a basic aromatic heterocycle. (www.wikipedia.org visited on 23/5/2009)
1, 2, 4 Triazole is produced by the reaction between formamide and hydrazine hydrate. Reaction temperature is high. At high temperature, formamide decompose and converted into formic acid. This formic acid reacts with hydrazine hydrate and form 4-amino 1, 2, 4 Triazole. This is unwanted isomer. It decreases the quality and yield. Concentration of 4-amino 1, 2, 4 Triazole may be around 1 - 5%.
WO 85/02842 discloses a process for the preparation of 1, 2, 4-triazole by the ring closure of diformyl hydrazine prepared by the formylation of hydrazine and ammonia which comprises reacting ammonium formiate with hydrazine hydrate by feeding continuously hydrazine or hydrazine hydrate at 120-1600C to the aqueous solution of ammonium formiate and removing continuously the formed water ammonia from the mixture and isolating, if desired, the cold precipitated triazole from the mixture.
Objects of the Invention:
The main object of the present invention is to produce 1, 2, 4, Triazole with minimum formation of 4 amino 1, 2, 4 Triazole.
Another object of the present invention is to increase yield of 1, 2, 4, Triazole.
Further object of the present invention is to produce 1, 2, 4 Triazole by quick and easy process.
Summary Of The Invention:
The present invention relates to a process for the preparation of pure 1, 2, 4 Triazole in a very good yield by minimizing the formation of 4 amino 1, 2, 4 Triazole. A process for the preparation of 1, 2, 4 Triazole includes reacting hydrazine hydrate (80%) and formamide in a molar ratio of formamide to hydrazine of 2.2: 1 to 3:1. Hydrazine hydrate is introduced into the formamide at the temperature range of 160oC to 200oC. Simultaneously aqueous ammonia (20%) of similar quantity of hydrazine hydrate also introduce into the formamide to minimum the formation of 4 amino 1, 2, 4 Triazole.
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 liquor ammonia below the surface of formamide in the reactor along with hydrazine hydrate is added. So, whatever quantity of formamide decomposes to formic acid reacts with ammonia and converts into ammonium formate. Ammonium formate reacts with hydrazine hydrate and form 1, 2, 4 Triazole. Thus, formation of 4-amonia 1, 2, 4 Triazole is minimized.
In the present invetnion 80% conentrated hydrazine hydrate and 20% conentrated aqueous ammonia are used.
The molar ratio of formamide to hydrazine hydrate is 2.2: 1 to 3:1.
The process for prearation of 1, 2, 4- Triazole comprising:
(i) Formamide is heated up to 160- 200°C and maintained in the temperature range of 160-200°C by the use of a temperature controller.
(ii) Hydrazine hydrate is slowly introduced as a fine stream under the surface of the stirred formamide.
(iii) Simultaneously aqueous ammonia is introduced with the separate stream under the surface of stirred formamide.
(iv) Water is distilled out of the reaction vessel through a suitable distillation column.
(v) After the addition of the hydrazine is completed, the temperature of the reaction mix is maintained at the 160-200°C temperature for 1/2 hours.
(vi) The reaction mixture is then cooled to ambient temperature and provides a light yellow solution which crystallizes on standing.
The solution is containing 75-80% 1, 2, 4-triazole, 0.1 – 1% 4 amino 1, 2, 4 Triazole and remaining unreacted formamide.
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.
Example 1: Conventional method

A five liter, five-neck, round bottom flask is charged with 4000 g formamide. The temperature of the formamide is then raised to 170°C and maintained in the range of 140-200°C by the use of a temperature controller. Hydrazine hydrate (80%) 2730 g is then slowly introduced as a fine stream under the surface of the stirred formamide. During the hydrazine addition, a vigorous evolution of ammonia, water and formic acid takes place. Water is distilled out of the reaction vessel through a suitable distillation column. It is advantageous to maintain the vapor temperature in the top of the column at less than 100°C in order to minimize losses of formamide. After the addition of the hydrazine is completed, the temperature of the reaction mix is maintained at the 140-200°C temperature for 1/2 hours. The reaction mixture is then cooled to ambient temperature and provides a light yellow solution which crystallizes on standing. The solution is containing 75 - 80% 1, 2, 4-triazole, 1 – 5% 4 amino 1, 2, 4 Triazole and remaining unreacted formamide.
Example 2:

A five liter, five-neck, round bottom flask is charged with 4000 g formamide. The temperature of the formamide is then raised to 170°C and maintained in the range of 140-200°C by the use of a temperature controller. Hydrazine hydrate (80%) 2730 g is then slowly introduced as a fine stream under the surface of the stirred formamide. Simultaneously aqueous ammonia (20%) also introduce with the separate stream under the surface of stirred formamide. During the hydrazine addition, a vigorous evolution of ammonia, water and formic acid takes place. Water is distilled out of the reaction vessel through a suitable distillation column. Formic acid remain in the reactor which convert into ammonium formate and at last it reacts with hydrazine and convert into 1, 2, 4 Triazole. It is advantageous to maintain the vapor temperature in the top of the column at less than 100°C in order to minimize losses of formamide. After the addition of the hydrazine is completed, the temperature of the reaction mix is maintained at the 140-200°C temperature for 1/2 hours. The reaction mixture is then cooled to ambient temperature and provides a light yellow solution which crystallizes on standing. The solution is containing 75-80% 1, 2, 4-triazole, 0.1 – 0.5% 4 amino 1, 2, 4 Triazole and remaining unreacted formamide.

We Claim:
1. A process for preparation of 1, 2, 4 triazole with minimum formation of 4-amino 1, 2, 4 triazole comprising:
(i) heating formamide up to 160 - 200°C and maintaining temperature in the range of 160 - 200°C by using temperature controller;
(ii) introducing hydrazine hydrate as a fine stream under the surface of the stirred formamide;
(iii) simultaneously introducing aqueous ammonia with the separate stream under the surface of stirred formamide;
(iv) distilling out water through a suitable distillation column;
(v) after completing addition of the hydrazine, maintaining the temperature of the reaction mix at the 160 - 200°C temperature for 1/2 hours;
(vi) cooling reaction mixture to ambient temperature;
(vii) crystallizing a light yellow solution on standing.

2. The process as claimed in claim 1 wherein 80% conentrated hydrazine hydrate is used.
3. The process as claimed in claim 1 wherein 20% aqueous ammonia is used.
4. The process as claimed in claim 1 molar ratio of formamide to hydrazine hydrate is 2.2: 1 to 3:1.
5. The process for preparation of 1, 2, 4 triazole with minimum formation of 4-amino 1, 2, 4 triazole substantially as described herein before and with reference to the foregoing examples.