Claims
- 1. A process for the preparation of a thiophene derivative of the formula I: ##STR12## in which R.sup.1 to R.sup.5, independently of one another, have the following meanings:
- R.sup.1, R.sup.4 and R.sup.5 are, independently of one another, hydrogen, C.sub.1 -C.sub.4 -alkyl radicals, C.sub.5 -C.sub.6 -cycloalkyl radicals, araliphatic radicals, aromatic radicals, alkoxycarbonyl, carboxamido, acyl radicals or CN; and
- R.sup.2 and R.sup.3 are, independently of one another, hydrogen; C.sub.1 -C.sub.4 -alkyl radicals, optionally substituted by COOCH.sub.3, COOC.sub.2 H.sub.5, OH, F, Cl, Br, (C.sub.1 -C.sub.4)-alkoxy, NH.sub.2 or (C.sub.1 -C.sub.8)-alkylamino groups; C.sub.5 -C.sub.6 -cycloalkyl radicals, araliphatic radicals or aromatic radicals, optionally substituted by OH, OCH.sub.3, OC.sub.2 H.sub.5, F, Cl or Br; or acyl radicals; and, in addition, one of the two radicals R.sup.2 and R.sup.3 can also denote alkoxycarbonyl, or R.sup.2 and R.sup.3, together with the N atom to which they are attached, can also form a 5-membered to 7-membered ring which can also contain another heteroatom of the type O, S or N as a ring member;
- by dehydrogenating a dihydrothiophene having the formula IIa and/or IIb: ##STR13## in which the radicals R.sup.1 to R.sup.5 have the same meaning as in formula I, which comprises carrying out the dehydrogenation by means of H.sub.2 O.sub.2 and in two stages,
- (a) by reacting a dihydrothiophene of the formula IIa and/or IIb with an at least approximately equimolar amount of H.sub.2 O.sub.2 in a neutral solvent or diluent in the absence of acid, in the course of which the 1-oxide of the initial dihydrothiophene is formed, and
- (b) by adding an acid to the dihydrothiophene 1-oxide formed in stage (a), with or without isolation of the latter, in the course of which the dihydrothiophene 1-oxide undergoes rearrangement into the thiophene derivative of the formula I.
- 2. A process for the preparation of a dihydrothiophene 1-oxide of the formula IIIa or IIIb: ##STR14## in which R.sup.1 to R.sup.5, independently of one another, have the following meanings:
- R.sup.1, R.sup.4 and R.sup.5 are, independently of one another, hydrogen, C.sub.1 -C.sub.4 -alkyl radicals, C.sub.5 -C.sub.6 -cycloalkyl radicals, araliphatic radicals, aromatic radicals, alkoxycarbonyl, carboxamido, acyl radicals or CN; and
- R.sup.2 and R.sup.3 are, independently of one another, hydrogen; C.sub.1 -C.sub.4 -alkyl radicals, optionally substituted by COOCH.sub.3, COOC.sub.2 H.sub.5, OH, F, Cl, Br, (C.sub.1 -C.sub.4)-alkoxy, NH.sub.2 or (C.sub.1 -C.sub.8)-alkylamino groups; C.sub.5 -C.sub.6 -cycloalkyl radicals, araliphatic radicals or aromatic radicals, optionally substituted by OH, OCH.sub.3, OC.sub.2 H.sub.5, F, Cl or Br; or acyl radicals; and, in addition, one of the two radicals R.sup.2 and R.sup.3 can also denote alkoxycarbonyl, or R.sup.2 and R.sup.3, together with the N atom to which they are attached, can also form a 5-membered to 7-membered ring which can also contain another heteroatom of the type O, S or N as a ring member;
- which comprises reacting a dihydrothiophene of the formula IIa and/or IIb: ##STR15## in which R.sup.1 to R.sup.5 have the same meanings as in the formula IIIa and IIIb, with an at least equimolar amount of H.sub.2 O.sub.2 in a neutral solvent or diluent in the absence of acid.
- 3. A dihydrothiophene 1-oxide of the formula IIIa or IIIb: ##STR16## in which R.sup.1 to R.sup.5, independently of one another, have the following meanings:
- R.sup.1, R.sup.4 and R.sup.5 are, independently of one another, hydrogen, C.sub.1 -C.sub.4 -alkyl radicals, C.sub.5 -C.sub.6 -cycloalkyl radicals, araliphatic radicals, aromatic radicals, alkoxycarbonyl, carboxamido, acyl radicals or CN; and
- R.sup.2 and R.sup.3 are, independently of one another, hydrogen; C.sub.1 -C.sub.4 -alkyl radicals, optionally substituted by COOCH.sub.3, COOC.sub.2 H.sub.5, OH, F, Cl, Br, (C.sub.1 -C.sub.4)-alkoxy, NH.sub.2 or (C.sub.1 -C.sub.8)-alkylamino groups; C.sub.5 -C.sub.6 -cycloalkyl radicals, araliphatic radicals or aromatic radicals, optionally substituted by OH, OCH.sub.3, OC.sub.2 H.sub.5, F, Cl or Br; or acyl radicals; and, in addition, one of the two radicals R.sup.2 and R.sup.3 can also denote alkoxycarbonyl, or R.sup.2 and R.sup.3, together with the N atom to which they are attached, can also form a 5-membered to 7-membered ring which can also contain another heteroatom of the type O, S or N as a ring member.
- 4. The process for the preparation of a thiophene derivative of the formula I as claimed in the definition in claim 1, wherein an acid is added to a dihydrothiophene 1-oxide of the formula IIIa or IIIb: ##STR17## in which R.sup.1 to R.sup.5 are as claimed in claim 1, in the course of which the dihydrothiophene 1-oxide undergoes rearrangement to give a thiophene derivative of the formula I.
- 5. The process as claimed in claim 1, wherein the radicals R.sup.1 to R.sup.5 in the formulae I, IIa and IIb have the following meaning:
- R.sup.1, R.sup.4 and R.sup.5 are, independently of one another hydrogen, C.sub.1 -C.sub.4 -alkyl, C.sub.5 -C.sub.6 -cycloalkyl, CH.sub.2 -C.sub.6 H.sub.5, C.sub.6 H.sub.5, COOCH.sub.3, COOC.sub.2 H.sub.5, CONH.sub.2, COCH.sub.3, COC.sub.2 H.sub.5 or CN;
- R.sup.2 and R.sup.3 are, independently of one another hydrogen, C.sub.1 -C.sub.4 -alkyl, optionally substituted by COOCH.sub.3 or COOC.sub.2 H.sub.5, C.sub.5 -C.sub.6 -cycloalkyl, (CH.sub.2).sub.1-3 -C.sub.6 H.sub.5, C.sub.6 H.sub.5, optionally substituted by OH, OCH.sub.3, OC.sub.2 H.sub.5, F, Cl or Br, or CO(C.sub.1 -C.sub.5 -alkyl) in which the alkyl radical can be substituted by OH, F, Cl, Br, (C.sub.1 -C.sub.4)-alkoxy, NH.sub.2 or (C.sub.1 -C.sub.8)-alkylamino groups, and one of the radicals R.sup.2 or R.sup.3 can, in addition, also be COOCH.sub.3 or COOC.sub.2 H.sub.5, or R.sup.2 and R.sup.3, together with the N atom to which they are attached, form a pyrrolidino, piperidino, morpholino, piperazino or homopiperazino ring.
- 6. The process as claimed in claim 1, wherein the reaction is carried out in water or a neutral organic solvent, as a solvent or diluent.
- 7. The process as claimed in claim 2, wherein the radicals R.sup.1 to R.sup.5 in the formulae IIa, IIb, IIIa and IIIb have the following meaning:
- R.sup.1, R.sup.4 and R.sup.5 are, independently of one another, hydrogen, C.sub.1 -C.sub.4 -alkyl, C.sub.5 -C.sub.6 -cycloalkyl, CH.sub.2 --C.sub.6 H.sub.5, C.sub.6 H.sub.5, COOCH.sub.3, COOC.sub.2 H.sub.5, CONH.sub.2, COCH.sub.3, COC.sub.2 H.sub.5 or CN;
- R.sup.2 and R.sup.3 are, independently of one another, hydrogen, C.sub.1 -C.sub.4 -alkyl, optionally substituted by COOCH.sub.3 or COOC.sub.2 H.sub.5, C.sub.5 -C.sub.6 -cycloalkyl, (CH.sub.2).sub.1-3 --C.sub.6 H.sub.5, optionally substituted by OH, OCH.sub.3, OC.sub.2 H.sub.5, Cl or Br, or CO(C.sub.1 -C.sub.5 -alkyl) in which the alkyl radical can be substituted by OH, F, Cl, Br, (C.sub.1 -C.sub.4)-alkoxy, NH.sub.2 or (C.sub.1 -C.sub.8)-alkylamino groups, and one of the radicals R.sup.2 or R.sup.3 can, in addition, also be COOCH.sub.3 or COOC.sub.2 H.sub.5, or R.sup.2 and R.sup.3 together with the N atom to which they are attached, form a pyrrolidino, piperidino, morpholino, piperazino or homopiperazino ring.
- 8. The process as claimed in claim 2, wherein the reaction is carried out in water or a neutral organic solvent as a solvent or diluent.
- 9. The process as claimed in claim 4, wherein the radicals R.sup.1 to R.sup.5 in the formulae I, IIIa and IIIb have the following meaning:
- R.sup.1, R.sup.4 and R.sup.5 are, independently of one another, hydrogen, C.sub.1 -C.sub.4 -alkyl, C.sub.5 -C.sub.6 -cycloalkyl, CH.sub.2 --C.sub.6 H.sub.5, C.sub.6 H.sub.5, COOCH.sub.3, COOC.sub.2 H.sub.5, CONH.sub.2, COCH.sub.3, COC.sub.2 H.sub.5 or CN;
- R.sup.2 and R.sup.3 are, independently of one another, hydrogen, C.sub.1 -C.sub.4 -alkyl, optionally substituted by COOCH.sub.3 or COOC.sub.2 H.sub.5, C.sub.5 -C.sub.6 -cycloalkyl, (CH.sub.2).sub.1-3 --C.sub.6 H.sub.5, optionally substituted by OH, OCH.sub.3, OC.sub.2 H.sub.5, Cl or Br, or CO(C.sub.1 -C.sub.5 -alkyl) in which the alkyl radical can be substituted by OH, F, Cl, Br, (C.sub.1 -C.sub.4)-alkoxy, NH.sub.2 or (C.sub.1 -C.sub.8)-alkylamino groups, and one of the radicals R.sup.2 or R.sup.3 can, in addition, also be COOCH.sub.3 or COOC.sub.2 H.sub.5, or R.sup.2 and R.sup.3, together with the N atom to which they are attached, form a pyrrolidino, piperidino, morpholino, piperazino or homopiperazino ring.
- 10. The process as claimed in claim 4, wherein the reaction is carried out in water or a neutral organic solvent as a solvent or diluent.
- 11. A dihydrothiophene 1-oxide as claimed in claim 3, wherein the radicals R.sup.1 to R.sup.5 have the following meaning:
- R.sup.1, R.sup.4 and R.sup.5 are, independently of one another, hydrogen, C.sub.1 -C.sub.4 -alkyl, C.sub.5 -C.sub.6 -cycloalkyl, CH.sub.2 --C.sub.6 H.sub.5, C.sub.6 H.sub.5, COOCH.sub.3, COOC.sub.2 H.sub.5, CONH.sub.2, COCH.sub.3, COC.sub.2 H.sub.5 or CN;
- R.sup.2 and R.sup.3 are, independently of one another, hydrogen, C.sub.1 -C.sub.4 -alkyl, optionally substituted by COOCH.sub.3 or COOC.sub.2 H.sub.5, C.sub.5 -C.sub.6 -cycloalkyl, (CH.sub.2).sub.1-3 --C.sub.6 H.sub.5, optionally substituted by OH, OCH.sub.3, OC.sub.2 H.sub.5, Cl or Br, or CO(C.sub.1 -C.sub.5 -alkyl) in which the alkyl radical can be substituted by OH, F, Cl, Br, (C.sub.1 -C.sub.4)-alkoxy, NH.sub.2 or (C.sub.1 -C.sub.8)-alkylamino groups, and one of the radicals R.sup.2 or R.sup.3 can, in addition, also be COOCH.sub.3 or COOC.sub.2 H.sub.5, or R.sup.2 and R.sup.3, together with the N atom to which they are attached, form a pyrrolidino, piperidino, morpholino, piperazino or homopiperazino ring.
- 12. The process as claimed in claim 1, wherein the reaction is carried out in water, a C.sub.1 -C.sub.4 -alkanol or a mixture thereof.
- 13. The process as claimed in claim 2, wherein the reaction is carried out in water, a C.sub.1 -C.sub.4 -alkanol or a mixture thereof.
- 14. The process as claimed in claim 4, wherein the reaction is carried out in water, a C.sub.1 -C.sub.4 -ethanol or a mixture thereof.
Priority Claims (1)
Number |
Date |
Country |
Kind |
3804794 |
Feb 1988 |
DEX |
|
Parent Case Info
This application is a continuation of application Ser. No. 07/449,443, filed Dec. 11, 1989, now abandoned, which is a continuation of application Ser. No. 07/310,189, filed Feb. 14, 1989, now abandoned.
US Referenced Citations (5)
Foreign Referenced Citations (3)
Number |
Date |
Country |
1643325 |
Dec 1976 |
DEX |
WO8702220 |
Apr 1987 |
WOX |
2194530 |
Mar 1988 |
GBX |
Non-Patent Literature Citations (4)
Entry |
Fieser et al., Reagents for Organic Synthesis, vol. 4, p. 8. |
W. Theilheimer, Synthetic Methods of Organic Chemistry, vol. 17, p. 233, 1963. |
A. P. Stoll & R. Suess, Helvetica Chimica Acta, vol. 57, Fasc. 8 (1974) Nos. 269-270, pp. 2487-2492. |
T. Takaya et al., Bull. Chem. Soc. Japan, vol. 41 (1968), pp. 2086-2095. |
Continuations (2)
|
Number |
Date |
Country |
Parent |
449443 |
Dec 1987 |
|
Parent |
310189 |
Feb 1989 |
|