CS257387B1

CS257387B1 - Process for preparing 2-benzothiazole sulfenic acid morpholide

Info

Publication number: CS257387B1
Application number: CS923286A
Authority: CS
Inventors: Marian Valentiny; Julius Kozma; Peter Toman; Jan Holcik; Tomas Kubecka; Jan Masek; Karel Hlinstak; Ivan Kopernicky; Milan Petro; Jana Muchova; Stanislav Kacani
Original assignee: Marian Valentiny; Julius Kozma; Peter Toman; Jan Holcik; Tomas Kubecka; Jan Masek; Karel Hlinstak; Ivan Kopernicky; Milan Petro; Jana Muchova; Stanislav Kacani
Priority date: 1986-12-11
Filing date: 1986-12-11
Publication date: 1988-04-15

Abstract

Riešenie sa týká sposobu přípravy morfolidu 2-benztiazolsulfénovej kyseliny vzorca I oxidácion roztoku alebo suspenzie 2-merkaptobenztiazolu (2-MBT) v morfoline alebo v zmesi morfolín — voda peroxidom vodíka v molárnom přebytku 5 až 25 % na celkové látkové množstvo 2-MBT, pri teplote 5 až 40 °C. Do předloženého morfolínu alebo zmesi morfolín — voda, obsahujúcemu 20 až 45 % hmot. 2-MBT sa v priebehu 3 až 12 hodin přidává oxidačně činidlo, pričom celkové množstvo vody v 2-MBT, morfolíne a peroxide vodíka vstupujúce do procesu, mů že byť maximálně rovné přebytku morfolí nu nad stechiometrické množstvo vztiahnuté na 2-MBT, keď množstvá vody a morfolínu sú vyjádřené « hmotnostných jednotkách.The solution concerns the method of preparation of morpholide of 2-benzthiazolesulfenic acid of formula I by oxidation of a solution or suspension of 2-mercaptobenzthiazole (2-MBT) in morpholine or in a mixture of morpholine — water with hydrogen peroxide in a molar excess of 5 to 25% to the total substance amount of 2-MBT, at a temperature of 5 to 40 °C. To the presented morpholine or a mixture of morpholines — water, containing 20 to 45% by mass. An oxidizing agent is added to 2-MBT within 3 to 12 hours, whereby the total amount of water in 2-MBT, morpholine and hydrogen peroxide entering the process can be at most equal to the excess of morpholine over the stoichiometric amount based on 2-MBT, when the amounts of water and morpholine are expressed in « mass units.

Description

257387

The invention relates to a process for the preparation of morpholine 1-benzothiazolulenic acid of formula I

(by oxidative condensation of 2-mercaptobenzothiazole and morpholine with hydrogen peroxide. Said sulfenamide is used as a safe accelerator in the vulcanization of natural and butadiene rubber blends. Several methods for its preparation have been described in the literature: 2-mercapto-benzothiazole , its sodium salt or disulfide with N-chloromorpholine (DE 1 900 133, EP10 477), oxidation of 2-mercaptobenzothiazole amorpholine with sodium hypochlorite solution (SU 178788, SU17822), catalytic oxygenation (SU4182) 873, EP 29 718) or by electrochemical oxidation of 2-mercaptobenzothiazole or its disulfide and morpholine in dimethylformamide [JP 80 06 423]. Hydrogen peroxide is mentioned as an oxidizing agent in GB 519 617, GB 655 668 and US 419 The disadvantage is the low yield, which does not achieve the required quality. The Soviet patent SU 689 174 uses a hydrogen peroxide solution to oxidize the mixture of 2-mercaptobenzothiazole and morpholine. morpholine, yielding 90 to 94% sulfenamide. When the hydrogen peroxide solution alone is used, the yield is only 70%. A disadvantage of this process is the large excess of morpholine, the molar ratio of 2-mercaptobenzothiazole: morpholine 1: 9.4 to 11.3, which is negatively reflected in the increase in equipment volume as well as the increase in morpholine regeneration costs. According to DE2 726 901, 2-benzothiazole sulphonic acid morpholide is prepared by placing the hydrogen peroxide on 2-mercaptobenzothiazole in coccorpholine, requiring at least a multiple of the stoichiometric amount of amorpholine relative to 2-mercaptobenzothiazole (yield under the following conditions: 88.4. 86.7 ° C). The maximum yield (95.7%, active substance 98.0%) is obtained at a molar ratio of 2-mercapto-benzothiazole: morpholine 1: 17.5.

The hydrogen peroxide concentration is greater than 15.0% by weight, preferably 30.0% by weight in excess. The water content of the initial solution should not exceed 15% by weight. The product is isolated after distilling 80-90 ° C of morpholine from the reaction mixture, adding a significant amount of water (1000 ml per mole-2-mercaptobenzothiazole). The described process has a number of disadvantages. In order to obtain at least 97.0% of the active ingredient sulfenamide, a large excess of morpholine (almost twelve times the stoichiometric amount based on 2-mercapto-tobenzothiazole) at which the yield is 91.9% is essential.

At lower molar excesses of morpholine, the quality of the product decreases significantly. Large volumes of morpholine complicate! Another disadvantage of the process is the 30-70% -ollar excess of oxidizing agent, which results in the decomposition of morpholine in its regeneration as well as the overall increase in costs. Po-dla MS. AO 209 594, N-substituted benzothiazole-2-sulfenamides are prepared by the oxidation amine salt of 2-mercaptobenzothiazole in the presence of 0.05 to 3 moles of free aminour solution of sodium hypochlorite or hydrogen peroxide, wherein the concentration of 2-mercaptobenzothiazole in solution or suspension is 5 to 20%. A disadvantage of the process is the low concentration of 2-mercaptobenzothiazole in solution or suspension, thereby increasing the amount of mother liquors after product separation, thereby requiring (energy) regeneration of the amine.

The above drawbacks are eliminated by the preparation of morpholide 2-benzothiazole sulphonic acid of Formula 1

(?) according to the invention, by oxidizing a solution or a suspension of 2-mercaptobenzothiazole in morpholine or in a morpholine-water hydrogen peroxide molar excess of 5.0 to 25.0% by weight. to the total amount of 2-mercaptobenzothiazole at 5 to 40 degrees Celsius. The present invention is based on the fact that the oxidation condensation is carried out at higher concentrations of 20.0 to 45.0% by weight of 2-mercaptobenzothiazole in morpholine or in a morpholine-water mixture.

A solution of hydrogen peroxide is metered into a solution or suspension of .alpha.-mercapto-benzothiazole in morpholine or a mixture of morpholine-water under vigorous stirring for 3 to 12 hours. The hydrogen peroxide concentrate, the water concentration in morpholine and the water content of the 2-mercaptobenzo-thiazole are chosen so that the total amount of water in these raw materials is the maximum morpholine excess above the stoichiometric amount: 257387 m (H2O) = m (2-MBT ). x (H2O) exp, 2-MBT-1-m (MOR). x (H 3 O) exp. MOR + m (H 2 O 2) · x (H 2 O) exp. H2O2 - m (MOR) - m (2-MBT). M (MOR / M (2-MBT)

m (H -, O) m (2-MBT) m (MOR) m (H 2 O 2) x (H 2 O) exp. 2-MBT x (H2O) exp. MORx (H2O) exp. II2O2 M (MOR) M (2-MBT) - mass of water = mass of 2-mercaptobenzothiazole 11 = mass of morpholine = mass of hydrogen peroxide - mass fraction of water in 2-mercapto-benzothiazole - mass fraction of water in morpholine = mass fraction of water in peroxide in mole weight of morpholine - molar mass of 2-mercaptobenzothiazole The preferred method of the invention is to carry out the reaction at higher concentrations of 2-mercaptobenzothiazole (molar ratio of 2-mercaptobenzothiazole: morpholine 1: 2 to 8), significantly reduces the total amount of morpholine in the process. As a result, the overall volume reduction of equipment as well as the cost of regenerative morpholine from the mother liquors is further found to be highly selective with respect to 2-mercaptobenzothiazole, according to the present invention. as well as hydrogen peroxide. In addition to the advantages of the raw materials resulting from the increased selectivity, favorable preconditions are created for increasing the morpholine recovery efficiency of the mother liquors. The process of preparing the sulfenamide according to the invention does not require precise and constant feeds in the starting materials. What is important is the total amount of water entering the reaction. This makes it possible to select the most economical combination of raw materials. A further advantage is that the process thus conducted provides a suspension of the sulfenamide in the morpholine-water mixture from which the product is isolated by filtration, while the liquid phase composition is minimized by its solubility.

The following examples illustrate but do not limit the invention

To a solution of 2-mercaptobenzothiazole in morpholine (2-mercaptobenzothiazole concentration 20.0% by weight) prepared from 169.5 g of 2-mercaptobenzothiazole (1.0 mol; active ingredient content 98.68%) and 665.5 g of morpholine ( Hydrogen peroxide (408.0 g, 1.2 mol; 10.0 wt.%) Was added with vigorous stirring and cooling over 3 hours at 25-30 ° C with vigorous stirring and cooling. C. After the oxidizing agent was added, the suspension was cooled to 15 ° C, the 2-benzothiazole sulfenic acid morpholide was filtered off, the filter cake washed with 40% morpholine (200.0 g), water (900.0). g) and dried. 226.9 g (89.9%) of the product were obtained with an active substance content of 98.1%, with a heating temperature of 82-84 ° C. Unreacted morpholine is recovered from the mother liquors and returned to the process. Example 2

To a suspension of 2-mercaptobenzothiazole in morpholine (2-mercaptobenzothiazole concentration 44.8% by weight) prepared from 178.4 g wet 2-mercaptobenzothiazole (1.0 mole; 95.0% dry 2-mercaptobenzothiazole containing 98.68%) and 195.2 g of morpholine (2.2 moles; active ingredient content 98.18%) was added by intensive stirring and stirring to 130.3 g of hydrogen peroxide (1.15 mol; concentration of 30.0% by weight) over 12 hours at 30 ° C. to 35 ° C. After addition of the oxidizing agent, the suspension is cooled to 15 ° C, the 2-benzothiazole-sulfenic acid morpholide is filtered off, the filter cake is washed with 40.0% solution of morpholine (200.0 g), water (900.0 g). ) and dried. 229.6 g (90.9%) of the product were obtained with an active ingredient content of 98.8%, with a temperature of 83-85 ° C. Unreacted morpholine is recovered from the mother liquors and returned to the process. Example 3

To a solution of 2-mercaptobenzothiazole in morpholine-water (concentration of 2-mercapobenzothiazole 25.0% by weight) prepared from 169.5 g of 2-mercaptobenzothiazole (1.0 mole; active ingredient content) 98.68% ) and 497.8 g of a solution of morpholine in water (4.0 moles; concentration 70.0% w / w) of intensive stirring and cooling adds 130.0 g of hydrogen peroxide (1.25 mol, concentration 32.7%). weight) over 6 hours at 15-20 ° C.

After addition of the oxidizing agent, the suspension is cooled to 15 ° C, the 2-benzothiazosulphenoic acid morpholide is filtered off, the filter cake is washed with a 40.0% solution of morpholine (200.0 g) with water (900, 0 g) and dried. 228.0 g (90.3%) of product are obtained.

Claims

With an active substance content of 97.7%, with a melting point of 82-83 ° C. Unreacted morpholine is regenerated from the mother liquors, which is absorbed into the process. Example 4 To a solution of 2-mercaptobenzothiazole in morpholine-water (20.4% by weight 2-mercapto-tobenzothiazole) prepared from 188.5 g of wet 2-mercaptobenzothiazole (1.0 mol; 90.0%). % by weight of dry 2-mercaptobenzothiazole with an active substance content of 98.68%) and 631.6 g of a solution of morpholine in water (5.8 moles; concentration 87.8 80.0% by weight) with intensive mixing and cooling 187.0 g of hydrogen peroxide (1.1 mol, 20.0% by weight) are added over 8 hours at 25-30 ° C. After addition of the oxidizing agent, the suspension was cooled to 15 ° C, 2-benzothiazole sulfenic acid morpholide was filtered off, the filter cake was washed with 40.0% morphine solution (200.0 g) with water (900.0 g) and dried. 229.9 g (91.1%) of a product having an active ingredient content of 98.8% with a temperature of 84-86 ° C were obtained. Unreacted morpholine is recovered from the mother liquors and returned to the process. SUBJECT MATERIAL Preparation of 2-benzothiazole-sulfenic acid morpholide of formula I by N-N-O (ii) by oxidation of a solution or suspension of 2-mercaptobenzothiazole in morpholine or NA morpholine-water with hydrogen peroxide in a molar excess of 5.0 to 25.0% for a total amount of 2-mercaptobenzothiazole with a temperature of 5 to 40 ° C, characterized in that the morpholine or mixture of morpholine-water containing 20.0 up to 45.0% by weight of 2-mercaptobenzothiazolone adds an oxidizing agent over a period of 3 to 12 hours, wherein the total amount of water in the 2-mercaptobenzothiazole, morpholine and hydrogen peroxide entering the process can be at most equal to the morpholinone excess stoichiometric amount based na-mercaptobenzothiazole when the amounts of water of amorpholine are expressed in units of weight Severografia, np závod 7, Most Price 2,40 Kčs