DE2153794A1 - PROCESS FOR THE PREPARATION OF PERFLUORALKANE SULFONYL ISOCYANATES - Google Patents

Description

FARBENFABRIKEN BAYER AG LEVE RK U S EN-Bayerwerk GM / Βπ central area Patents, trademarks and licenses

2 6, Oct. 197t

Process for the preparation of perfluoroalkanesulfonyl isocyanates

The production of bifluoromethylsulfonyl isocyanate CF ₅ SO ₂ NCO from CF ₅ SO ₂ NSO and phosgene according to the equation

CF ₅ SO ₂ NSO + COCl ₂ ^ CF ₅ SO ₂ NCO + SOCl ₂

is known. However, the trifluoromethylsulfonyl isocyanate is obtained in poor yield ($ 29).

Surprisingly, a process has now been found, according to which one can take place without great expenditure on apparatus and in good yield Trifluoromethylsulfonyl isocyanate and other perfluoroalkanesulfonyl isocyanates obtained by trifluorinethylsulfonic acid amide or perfluoroalkanesulfonic acid amides with compounds of the formula

Hal-SO ₂ -NCO (Hai = F, Cl, Br, J) converts.

The present invention thus relates to a process for the preparation of perfluoroalkanesulfonyl isocyanates of the generally new Forme I.

⁽ \ i ^V 2n η 1 ™ 2- ^{NC ()} ( ⁿ = ¹ - Ό). Le Λ 1 5 ¹ H ') 5 -I-

3 O f) Ö 1 ') / Π.) 7

BAD ORiQiNAU

2) 53794

characterized in that compounds of the general formula

^C n ^F 2n ₊ 1 ^S0 2 ^NH 2 <* = ¹ " ¹⁸ >

with compounds of the formula

HaI-SO ₂ NCO (Hai = F, Cl, Br, J)

at temperatures of 20-200 ⁰ C, preferably 50-150 ⁰ C, is reacted.

Compounds of the general formula thus serve as starting material for the process according to the invention

^C n ^F 2n + 1 ^SO 2 ^NH 2 (n = 1-18).

These connections are known. Perfluoroalkanesulfonic acid amides are preferred with 1-8 carbon atoms used.

The perfluoroalkanesulfonic acid amides are made with compounds of the general formula

Hal-SO ₂ -NCO (Hai = F, Cl, Br, J) implemented. It is preferred

Cl-SO ₂ -NCO used. This connection is also known.

The method according to the invention is preferably carried out such that the reaction components are brought into contact with each other, wherein a reaction "tempera door 20-2 () 0 ° C, preferably 50-150 ⁰ C, is oingelialten. The process according to the invention can also be carried out using inert solvents. Γηquery coming inert Iichs

Γ. «A 1)«) f> 5 - '! - ■

0 9 8 1 ¹ J / 1 U 7 BAD ORIGINAL

are e.g. hydrocarbons such as benzene, cyclohexane or Gasoline, also halogenated hydrocarbons such as carbon tetrachloride, chlorobenzene or tetrachlorethylene, also Esters and ketones such as acetone or methyl butyl ketone and Cyclohexanone, sulfones such as tetramethylene sulfone, sulfoxides such as dimethyl sulfoxide, amides such as dimethyl acetamide or N-methylpyrrolidone.

The process according to the invention is carried out under as anhydrous conditions as possible.

The separation of the process products from the reaction mixture takes place in a conventional manner, e.g. by distillation, crystallization.

The products of the process behave towards compounds with reactive hydrogen atoms, e.g. towards Alcohols and amines like normal isocyanates. They are used to modify plastics, as water-binding agents in Paint systems, e.g. in polyurethane paint systems, and for production used by pesticidally active compounds.

Le A 13 903 - 3 -

3 0 9 8 19/1137

example 1

Representation of C ^ FqSO ₂
In a 1 l three-necked flask equipped with a stirrer, dropping funnel and distillation attachment, 250 g (0.8 mol) of 96% CgFgSO ₂ NH _{2 are dissolved} in 250 g of carefully dried tetramethylene sulfone and brought to a temperature of approx. 130 ° C. The first portion of an equimolar amount of approx. 115 g of ClSO ₂ NCO is then added through the dropping funnel. The mixture is stirred for some time under reflux and then begins with the constant lowering of the pressure to about 60 torr with the distillation. Only C ^ FgSO ₂ NCO contaminated by HCl, SO ₂ and CO _{2 is} distilled off, which has a lower boiling point than the pure substance due to the dissolved gases. Due to the constant replication of the HCl from the chlorosulfonamide formed, the desired substance cannot be obtained in pure form with this type of distillation. When no more C ^ FgSO ₂ NCO passes over, the pressure is increased again by letting in dry air and another 50 g of ClSO ₂ NCO are added. The mixture is then stirred for about 10 minutes and then distilled as already stated. This process is repeated twice with smaller amounts of ClSO _{2 NCO each time.}

The product obtained in this way can be purified by a single distillation.
Yield: 238 g = 91.5 %

The pure compound C »FgSO ₂ NCO has a melting point of -15 ° C and a boiling point of 128 ° C at normal pressure.

Example 2

Preparation of C ₈ F ₁₇ SO ₂ NCO

As in the preparation of C ^ FgSO ₂ NCO according to Example 1, 300 g of 92.5 tiger CgF ₁₇ SO ₂ NH ₂ (0.2 mol), dissolved in 400 g

Le A 13 963 - 4 -

3098 19/1137

Tetramethylene sulfone, the equimolar amount of ClSOpNCO (about 105 g) were added dropwise, and after some stirring at 130 ° C., the C ₈ F ₁₇ SO ₂ NCO formed was distilled off under a vacuum between 20 and 1 torr. This process is repeated once with 70 g and three times with approx. 35 g of ClSO _{2 NCO each time.} The resulting crude product is heavily contaminated and must then be distilled over a Vigreux column,
Yield of pure product: 211 g = 75 %. Melting point: 21-22 ° C
Boiling point: 55 ° C / 1 - 2 Torr

Example 3

Production of CF ₃ SO ₂ NCO

20 g (134 mmol) CF ₃ SO ₂ NH ₂ and 32 g (226 mmol) ClSO ₂ NCO are heated in a 100 ml single-necked flask with a packed column, column head and spider with four receiving flasks. This initially creates a clear solution, which becomes cloudy with further heating and finally has a finely crystalline precipitate. The CF, SOpNCO which has formed is distilled off in pure form from this reaction mixture under reduced pressure (approx. 600 torr) at 65.degree.

As soon as the temperature begins to rise, the distillation is ended, since the ClSO ₂ NCO then passes over. The CF ₃ SO ₂ NCO is distilled once more into a trap in the vacuum apparatus in order to remove _{the last traces of ClSO 2 NCO.} Yield: 18.9 g (80 fi of theory)
Melting point: -25 ° C
Boiling point: 71 ° C

le A 13 963 - 5 -

309819/1137

Claims (1)

Claim: ** Process for the preparation of Perfluoroalkanesulfonylisocyana- of the general formula C _n F _{2n +} JSO ₂ -NCO (n = 1-18) characterized in that compounds of the general formula ^C n ^F 2n + 1 ^S0 2 ^NH 2 (n = 1-18) with compounds of the formula HaI-SO ₂ NCO (Hai = F, Cl, Br, J) at temperatures of 20-200 ⁰ C, preferably 50-150 ⁰ C, is reacted. Le A 13 963 - 6 - 30981a / 1137