Process for preparing substituted thiophenesulfonyl isocyanates
View Patent ↗The present invention relates to a process for preparing compounds of the general formula (I) in which R 1 and R 2 are as defined in the description by reacting compounds of the formula (II) in which R 1 and R 2 are as defined in the description with phosgene in the absence of a base and in the presence of one or more diluents and also optionally of a catalyst.
1. A process for preparing a compound of formula (I)
in which
R 1 is alkoxy having from 1 to 4 carbon atoms, and
R 2 is alkyl having from 1 to 4 carbon atoms, comprising reacting a compound of formula II
with phosgene in the absence of a base and in the presence of at least one diluent and also optionally of a catalyst.
2. The process as claimed in claim 1 , wherein the reaction is carried out at a temperature from 100° C. to 150° C.
3. The process as claimed in claim 1 , wherein the diluent is selected from the group consisting of chlorobenzene and xylene.
4. The process as claimed in claim 1 , wherein the compound of formula (I) is reacted with an amine in a subsequent reaction step without intermediate isolation.
5. The process as claimed in claim 4 , wherein the amine is 5-methoxy -4-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one.
6. The process as claimed in claim 1 , which is performed in the presence of a catalytically active amount of a butyl isocyanate or pentyl isocyanate.
7. A process of claim 1 , wherein from 1.0-10 mol of phosgene is used per mole of the compound of formula II.
8. A process of claim 2 , wherein from 1.0-10 mol of phosgene is used per mole of the compound of formula II.