DD215313A1 - PROCESS FOR PREPARING NEW 1,3-OXATHIOLE - Google Patents

Abstract

The invention relates to a process for the preparation of novel substituted 2- (arenesulfonylimino) -1,3-oxathiols which are useful as reactive intermediates for the synthesis of pesticides, pharmaceuticals and dyes. The preparation is carried out by reaction of N-Arensulfonyldithiocarbamidsaeure-S-alkyl esters and alpha-haloketones in alcoholic-benzene solution at room temperature and optionally further boiling under reflux in aqueous, basic solution.

Description

2388

Process for the preparation of new 1,3-oxathiols

Field of application of the invention

Substituted 1,3-oxathiols are reactive intermediates for other Heterocyclensyntiiesen and may be starting materials for the preparation of pesticides and pesticides, pharmaceuticals and dyes.

Characteristic of the known technical solutions

Hitherto, starting from H-dialkyl (cycloalkyl) thlocarbamates (Hirai, K., Ishiba, T .: Chem. & Pharm. Bull (Tokyo) 20 (1972) * 304) or N-dialkyl (cycloalkyl) -dithiocarbamates (Ueno, Y., Okawara, M, Synthesis ( 1979, 182) and substituted & ^ - bromo-acetophenones, the corresponding intermediates with other cyclization methods always only in salts of 2- (dialkylamino) / (or · (cycloalkylamino)) -1,3-oxathiolen transferred. from trisubstituted thioureas and 6 ° haloketones were substituted 2-imino? -1,3-oxathiole obtained in free form (EP-PS A- 00 11473).

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Object of the invention

The aim of the invention are novel 1,3-oxathiols which carry an arenesulfonylimino group in the 2-position.

Explanation of the essence of the invention

The object of the invention was substituted 1,3-oxathiols of the general formula

R ²

R ¹ - S0 "- NJ,. _T

1 2 in the R and R arene and / or Hetarengruppen, which in turn may be mono- or polysubstituted by halogen, nitro, alkyl and / or alkoxy groups, to produce a simple and selective method. According to the invention, the compounds of general formula I are prepared by N-Arensulfonyl-dithiocarbamic acid-S-alkyl ester of the general formula

R ¹ - SO ₂ - NH - C - S - B?

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in which R has the same meaning as in formula X and

R- * is an alkyl group of 1 to 6 C atoms, first converted into the corresponding salts with equimolar, alcoholic sodium alcoholate solution, and subsequently at room temperature, dropwise and with an equimolar alcoholic-benzene solution of an alkyl halide ketone formula

₂ Br-CH ₉ -C-IT

^ III,

2 " . ·

in which R has the same meaning as in the formula I and can also be identical to R ¹ , in the compounds of the formula.

R ³ CH "II ₂

s · · * c - ir

R ¹ - SOp - H β C "CH-

12 3 in which R, R and R have the abovementioned meaning,

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If R is a 4-NO.sub.10-C.sub.1 H. -group, the compounds of the formula II are scarcely obtainable purely but cyclize directly to compounds of the formula I.

Otherwise, the compounds of the formula II are heated for about 1 hour in 1 to 5% aqueous, basic solution (K ₂ CO-, NagCO ,, alkali solutions) at reflux. The remaining residue is filtered off with suction and recrystallized from alcohol or acetonitrile. The new compounds are colorless to pale yellow crystalline substances. They are insoluble in water.

The following exemplary embodiments are intended to explain the invention in more detail without restricting it to them.

EXAMPLES

To a solution of 460 mg (0.02 mol) of sodium in 50 ml of alcohol and 4.9 g (0.02 mol) of N-benzenesulfonyl-dithiopcarbamic acid S-methyl ester at room temperature, an alcoholic-benzene solution of 4.0 g (0.02 mol) 6-^-bromo-acetophenone is added dropwise with stirring. After a short time, NaBr and the reaction product precipitate out. The mixture is stirred for a further 3 hours, briefly heated to 35 ^° C., then cooled, filtered off with suction and recrystallized from alcohol. The N-benzenesulfonyl-iminodithiocarbonic acid S-methyl-S-phenacyl diester is obtained in a yield of 41 % of theory and having a melting point of 130 to 132 ⁰ C.

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The crude product obtained from the described approach or the pure compound mentioned is refluxed for about 30 minutes in 5% strength K ₂ CO 4 solution. The remaining residue is filtered off with suction and recrystallised several times from ethanol or acetonitrile. The 2- (benzenesulfonylimino) 5-phenyl-1,3-oxathiole, wherein R ¹ R ² "CGH is _5, melting at 185 to 187 ⁰ C,

Yield: 42 % of theory Analytical data: C ₁₅ H ₁₁ NO ₃ S ₂ (317.4) Calculated: N 4.41 S 20.21 Found: N 4.41 S 19.95

IR / cm " ¹ /: C * C 1624

C = H 1525

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By the process according to the invention, for example, the following compounds of the formula I are prepared:

Table: 2- (Arenesulfonylimino) -1,3-oxathiols

R ¹ R ² * Mp. / ° C / Ausb./%/ C ₆ H ₅ ^C 6 ^H 5 185 to 187 42 ^C 6 ^H 5 4-Br-C ₆ H ₄ 207 to 209 72 ^C 6 ^H 5 4-NO ₂ -C ₆ H ₄ 239 to 241 86 4-CH ₃ -C ₆ H ₄ ^C 6 ^H 5 -160 to 163 34 4-CH ₃ -C ₆ H ₄ 4-OCH ₃ -C ₆ S ₄ 157 to 159 51 4-CH ₃ -C ₆ H ₄ 4-Br-C ₆ H ₄ 236 to 239 49 4-CH ₃ -C ₆ H ₄ 4-NO ₂ -C ₆ H ₄ 247 to 249 89 4-Cl-C ₆ H ₄ , 4-NO ₂ -C ₆ H ₄ 229 to 231 59

-c

Claims (1)

invention claim Process for the preparation of new 1,3-oxathiols of the general formula O rR ² R ¹ - SO ₂ - TJ (D, In which R and R are arene and / or hetaryl groups which may be monosubstituted or polysubstituted by halogen, nitro, alkyl and / or alkoxy groups by reaction of N-arensulfonyl-dithiocarbamic acid S-alkyl esters of the general formula formula 1 ⁰ R ¹ - SO ₀ - KH - C - S - (IV), 1 ^ in which R has the abovementioned meaning and R ^ are alkyl groups having 1 to 6 C atoms, and £-halo ketones of the general formula 0 Br-CH ₂ -CR ² 1983 * 1016 2388 2 '' in which R has the abovementioned meaning, characterized in that the compounds of the formula IV and of the formula III in alcoholic-benzene solution at room temperature to give compounds of the formula R ³ OH I ₂ s G ir. 1 ' " R ¹ - SO ₉ - N - C CH ² \ _e ^ II which cyclize in the presence of 1 to 5% strength aqueous alkali oxide solution with elimination of alkanethiol. -JULY 1983 * 101021