Process for the preparation of 4,4-dimethyl-6-ethynylthiochroman

1. A β-chloro vinyl carbonyl compound of the general formula:

wherein R is hydrogen or a hydrocarbyl of from 1 to about 15 carbon atoms.

2. The β-chloro vinyl carbonyl compound of claim 1 , wherein R is hydrogen.

3. The β-chloro vinyl carbonyl compound of claim 1 , wherein R is a hydrocarbyl group of 1 to about 15 carbon atoms.

4. The β-chloro vinyl carbonyl compound of claim 1 , wherein R is an alkyl group of 1 to 6 carbon atoms.

5. The β-chloro vinyl carbonyl compound of claim 1 , wherein R is a phenyl group.

6. The β-chloro vinyl carbonyl compound of claim 1 , having a purity of about 98%.

7. A process for the preparation of a β-chloro vinyl carbonyl compound of the general formula I:

wherein R is hydrogen or a hydrocarbyl of from 1 to about 15 carbon atoms, the process comprising reacting a 4,4-dimethyl-6-acetylthiochroman of the formula II

with an acid chloride and an amido-group containing compound of the general formula III

wherein R has the aforestated meanings and R 1 and R 2 can be the same or different and are hydrocarbyls of from 1 to about 15 carbon atoms or R 1 and R 2 together with the nitrogen atom to which they are bonded are joined together to form a heterocyclic group, optionally containing one or more additional heterocyclic atoms, or one of R 1 and R 2 together with the nitrogen atom to which it is bonded are joined together with the carbonyl radical to form a heterocyclic group, optionally containing one or more additional heterocyclic atoms to provide the β-chloro vinyl carbonyl compound of formula I.

8. The process of claim 7 , wherein the acid chloride is selected from the group consisting of phosphorous oxychloride, thionyl chloride, phosgene, oxalyl chloride and mixtures thereof.

9. The process of claim 7 , wherein the acid chloride is phosphorous oxychloride.

10. The process of claim 7 , wherein R is hydrogen and R 1 and R 2 each are hydrocarbyl groups of 1 to about 15 carbon atoms.

11. The process of claim 7 , wherein R is hydrogen and R 1 and R 2 each are hydrocarbyl groups of 1 to about 12 carbon atoms.

12. The process of claim 7 , wherein R is hydrogen and R 1 and R 2 each are hydrocarbyl groups of 1 to 6 carbon atoms.

13. The process of claim 7 , wherein R is hydrogen and R 1 and R 2 together with the nitrogen atom to which they are bonded are joined together to form a heterocyclic group.

14. The process of claim 7 , wherein R is a hydrocarbyl group of from 1 to about 15 carbon atoms and R 1 and R 2 are independently hydrocarbyl groups of from 1 to about 15 carbon atoms.

15. The process of claim 7 , wherein R is a hydrocarbyl of from 1 to about 15 carbon atoms and R 1 and R 2 together with the nitrogen atom to which they are bonded are joined together to form a heterocyclic group.

16. The process of claim 7 , wherein the amido-group containing compound is selected from the group consisting of dimethyl formamide, N -methyl formanilide, N-formyl piperidine, N-formyl morpholine, dimethyl acetamide, N -methyl pyrrolidone, N,N-dimethyl benzamide and mixtures thereof.

17. The process of claim 7 , wherein the amido-group containing compound is present in an amount of about 45 to about 90 weight percent, based on the total weight of the reaction mixture.

18. The process of claim 7 , wherein the amido-group containing compound is present in an amount of about 55 to about 75 weight percent, based on the total weight of the reaction mixture.

19. The process of claim 7 , wherein the acid chloride is present in a ratio of about 1:3 (w/v) to about 1:5 (w/v) with respect to the 4,4-dimethyl-6-acetylthiochroman.

20. The process of claim 7 , wherein the acid chloride is phosphorous oxychloride and the amido-group containing compound is dimethyl formamide.