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US 11,390,594 B2Granted
Procedure for the preparation of 2-cyanoimino-1,3-thiazolidine
AssigneeBayer CropScience AG
InventorsShekhar Kulkarni, Eric Rivadeneira
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Abstract
The disclosure provides for methods for preparing 2-cyanoimino-1,3-thiazolidine, which is an important building block for the preparation of crop protection active ingredients and pharmaceuticals. To this end, the disclosure provides for more efficient and improved methods of preparing 2-cyanoimino-1,3-thiazolidine.
Claims20
A method of preparing thiacloprid comprising:
- i) in a solvent, reacting cyanamide with carbon disulfide in the presence of a base to form dimetal N-cyanodithioiminocarbonate;
- ii) in a solvent, reacting dimetal N-cyanodithioiminocarbonate with a methylating agent to form metal methyl N-cyanodithioiminocarbonate;
- iii) in a solvent, reacting metal methyl N-cyanodithioiminocarbonate with 2-chloroethylammonium hydrochloride to form 2-cyanoimino-1,3-thiazolidine;
- and
- iv) reacting 2-cyanoimino-1,3-thiazolidine with cCMP in toluene;
- water;
- Aliquat 336;
- and sodium carbonate to produce Thiacloprid;
- wherein the method excludes the isolation and/or purification of one or more intermediates from one or more of steps (i), (ii), or (iii).
6 more elements
A method of preparing thiacloprid comprising:
- i) reacting cyanamide with carbon disulfide in the presence of sodium hydroxide and methyltrioctylammonium chloride to form disodium N-cyanodithioiminocarbonate;
- ii) reacting disodium N-cyanodithioiminocarbonate with dimethyl sulfate to form sodium methyl N-cyanodithioiminocarbonate;
- iii) reacting sodium methyl N-cyanodithioiminocarbonate with 2-chloroethylammonium hydrochloride to form 2-cyanoimino-1,3-thiazolidine;
- and
- iv) reacting 2-cyanoimino-1,3-thiazolidine with cCMP in toluene;
- water;
- Aliquat 336;
- and sodium carbonate to produce Thiacloprid;
- wherein the method excludes the isolation and/or purification of one or more intermediates from one or more of steps (i), (ii), or (iii).
6 more elements
Dependencies are inferred from the claim text.