DE2117650A1 - Difluorochloro- and monofluorodichloromethoxybenzoyl fluorides - Google Patents

Description

FARBWERKE HOECHST AG formerly Master Lucius & Brüning

File number: Dr.BE/le

Date: HOE 71 / F

Difluorochloro- and Monoflttordichloromethoxy-benzoyl fluoride

It is known that 3-trichloromethoxy-benzoyl chloride implement by the action of mixtures of antimony trifluoride and antimony pentachloride, to give 3-Trif Ί uormethoxy-benzoyl (see FIG. Zhur. Obshdßi Khim. 2i "9 ¹ S ~ ² ^ (I96l) CA. 5_0_, 23 ^ 08 d; Doklady. Akad. Nauk. SSSR 105 , S. "100-102 (1955) CA 5_0, 11270 b; Zhur. Obshchei Khim. 2J_, 518-26 (1957) CA. 51, I5518 d) · The however, corresponding lower fluorinated products are not described.

The invention relates to difluorochloromethoxybenzoyl fluorides and fluorodichloromiethoxybenzoyl fluorides of the general formula

Cl "F CO
3-n η

COF I with η = 1 or 2

and a process for their preparation or for the preparation of their mixtures, which is characterized in that the corresponding Trichloromethoxybenzoylchloride of the general formula

COCl II

2098437 1095

2TT7S5Q

with 1.5 "to 8 moles of hydrogen fluoride per mole of trichloromethoxybenzoyl chloride at temperatures between +60 and 130 C, preferably at 80 - 110 C, in a pressure vessel to implement.

It is understandable that at the lower temperatures, for example down to 60 ° C., the expenditure of time must be taken into account, which is necessary because of the reduction in the reaction rate. The reaction at higher temperatures around 13O ⁴ C, however, means that a certain proportion of trifluoromethoxybenzoyl fluoride is also formed. The reaction with hydrogen fluoride at the temperatures according to the invention requires the use of a pressure vessel or autoclave in which an increased reaction pressure is established. This pressure corresponds essentially to the vapor pressure of hydrogen fluoride at the respective temperature, increased by the partial pressure of the resulting hydrogen chloride, which is adjusted according to the filling volume and total volume of the autoclave.

The required pressure vessels are made of material that is under the reaction conditions are not attacked or only to a small extent; The preferred material for the vessel is primarily nickel, also steel, in particular stainless steel alloys such as the various V2A or V ^ A alloys (chromium-nickel alloys).

The molar ratio of the reactants hydrogen fluoride: Trichlormethoxybenzoylchlorid is for the production of Difluorchlorbenzoylfluorid generally JII or more, for example 3,5 '· 1 his 8: 1, preferably 3.5: 1 to 4: 1. The upper limit is not critical and should be seen more from the point of view of work-up. Less hydrogen fluoride is required for the production of fluorodichlorobenzyl fluoride or its mixture with difluorochlorobenzoyl fluoride; the ratio is, depending on the desired proportion of one or the other compound, between 1.5 1 to 3; 1, preferably 1.5: 1 to 2.8: 1, especially 2: 1 to 2.5: 1

20 98 4 3/1095

To carry out the reaction according to the invention, the reactants are combined in a suitable pressure vessel and heated to reaction temperature. The reaction takes place with increasing pressure and is after about 1-5 hours, preferably 2-3 hours, by distilling off hydrogen chloride \ md Hydrogen fluoride terminated. Then the reaction product is rectified, preferably under reduced pressure.

The compounds according to the invention can be converted by reaction with azides in inert solvents and thermal rearrangement the intermediate difluorochloro- or fluorodichloromethoxybenzoyl acids with elimination of nitrogen (Curtitis' shear Degradation) into the corresponding isocyanates, which in turn, in a manner known per se, Aireiter to N-alkylated ureas can be implemented. These ureas are excellent herbicides and their effectiveness is equivalent to that of them Trifluiv timthoxypheny! Are superior to ureas.

209843/1095 ORIGINAL BATHROOM

Example 1

In a nickel autoclave there are 90 g (3 »50 mol) of 3-trichloromethoxy-benzoyl chloride and 245 S '(12.25 moles) of hydrogen fluoride Heated to 90-100 ° C. for 3 hours. The resulting hydrogen chloride is released and the liquid reaction product under rectified under reduced pressure.

The work-up results:

662 g of 3-difluorochloromethoxy-benzoyl fluoride, b.p. 197-198 ° C

n ^ ° 1.4612.
This corresponds to a yield of 84.4 % of theory . Th.

At game 2

In a nickel autoclave, 274 g (0.96 mol) of 96? 3-trichloromethoxy-benzoyl chloride and 160 g (8.0 moles) of hydrogen fluoride Heated to 90-95 ° C. for 2.5 hours. The resulting Hydrogen chloride is relaxed and the unconverted hydrogen fluoride distilled off.

According to gas chromatographic analysis, the reaction product contains 96.9 % 3-difluorochloromethoxy-benzoyl fluoride.

Example 3

In a nickel autoclave are 0.22 g (3.0 mol) of 4-trichloromethoxy-benzoyl chloride and 210 g (10.5 mol) of hydrogen fluoride heated to 92-98 ° C. for 2.5 hours. The resulting hydrogen chloride is relaxed and the liquid reaction product is rectified under reduced pressure.

BAD 0WG4NAL 209843/1095

211 7 B 5 O

The work-up results:

3'66 g of 4-difluorochloromethoxy-benzoyl fluoride, b.p. 199 ° - 200 ° C, n ^ ° 1.4670.

This corresponds to a yield of 84.0 % of theory . Th. Example 4

In a nickel autoclave, 274 g (0.96 mol) of 96 ° 6iges 3-trichloromethoxybenzoyl chloride and 44 g (2.2 mol) of hydrogen fluoride are heated to 92 ° C. for 2 hours. The resulting hydrogen chloride is released.

According to gas chromatographic analysis, the reaction product contains

29.8 % 3-difluorochloromethoxy-berizoyl fluoride and 64.1 % 3-fluorodichloromethoxy-benzoyl fluoride, b.p. 122 at 24 torr

nj; ⁰ 1.4963

Example 5

In a stainless steel autoclave, 206 g (0.72 mol) of 96 ° oiges 3-trichloromethoxy-benzoyl chloride and 53 g (2.65 mol) hydrogen fluoride Heated to 92 ° - 94 ° C for 2 hours. The resulting hydrogen chloride is relaxed.

The reaction product contains according to gaschroraatographischor analysis

5,6 Jo 3-trifluoromethoxy-benzoyIfluoride 79 ι 65b 3-di fluoro chloromethoxy-benzoy If luoride 11, 85o 3-L) i ch 1 or riuormethoxy-benzoyl fluoride

209843/1095

BATH

Claims (2)

2 i 1 7 6 5 -G- Patent Claims: Compounds of the general formula L F -CO -4-)) - COF with η = 1 or 2 3-n η \ y / 2. A process for the preparation of the compounds or of mixtures of these compounds according to claim I ₁ characterized in that the corresponding tri-benzoyl chlo rmethoxy · hydrochloride of general formula Cl-C 0_ £) V ~ COCl with 1.5 to 8 moles of hydrogen fluoride per mole of trichloromethoxybenzoyl chloride brought to reaction at temperatures between a pressure vessel. benzoyl chloride at temperatures between + 6θ and H-I30 C in BATH ORIGINAL «· ■■" »- ■ 209843/1096 ^;