Method for producing 3,4-dihydroisoquinoline derivatives and production intermediates of same

1. A method for producing a compound represented by formula (1):

wherein R1 and R2 independently represent an optionally substituted alkyl group having 1 to 6 carbon atoms or R1 and R2 together with the carbon atom to which they are bound form an optionally substituted cycloalkyl group having 3 to 10 carbon atoms, X represents a halogen atom, optionally substituted alkyl group having 1 to 6 carbon atoms or optionally substituted alkoxy group having 1 to 6 carbon atoms, n represents an integer of 0 to 4, Y represents a halogen atom, optionally substituted alkyl group having 1 to 6 carbon atoms or optionally substituted alkoxy group having 1 to 6 carbon atoms, and m represents an integer of 0 to 4, comprising reacting a compound represented by formula (2):

wherein R1, R2, X, Y, n and m are the same as previously defined, in the presence of an acid.

2. The method for producing a compound represented by formula (1) described in claim 1 , wherein R1 and R2 independently represent an optionally substituted alkyl group having 1 to 6 carbon atoms.

3. The method for producing a compound represented by formula (1) described in claim 2 , wherein n is 0.

4. The method for producing a compound represented by formula (1) described in claim 1 , wherein a compound represented by formula (2) is obtained by reacting a compound represented by formula (3):

wherein R1, R2, X and n are the same as in claim 1 , with a compound represented by formula (4):

wherein Y and m are the same as in claim 1 .

5. The method for producing a compound represented by formula (1) described in claim 4 , wherein R1 and R2 independently represent an optionally substituted alkyl group having 1 to 6 carbon atoms.

6. The method for producing a compound represented by formula (1) described in claim 5 , wherein n is 0.

7. The method for producing a compound represented by formula (1) described in claim 4 , wherein a compound represented by formula (3) is obtained by hydrolyzing a salt containing a compound represented by formula (5):

wherein R1, R2, X and n are the same as in claims 4 and R3 is an alkyl group having 1 to 3 carbon atoms.

8. The method for producing a compound represented by formula (1) described in claim 7 , wherein R1 and R2 independently represent an optionally substituted alkyl group having 1 to 6 carbon atoms.

9. The method for producing a compound represented by formula (1) described in claim 8 , wherein n is 0.

10. The method for producing a compound represented by formula (1) described in claim 7 , wherein a salt containing a compound represented by formula (5) is obtained by reacting a compound represented by formula (6):

wherein R1, R2, X and n are the same as in claim 7 , with a salt containing a compound represented by formula (7):

wherein R3 is the same as in claim 7 and Z represents a halogen atom.

11. The method for producing a compound represented by formula (1) described in claim 10 , wherein R1 and R2 independently represent an optionally substituted alkyl group having 1 to 6 carbon atoms.

12. The method for producing a compound represented by formula (1) described in claim 11 , wherein n is 0.

13. A method for producing a compound represented by formula (1):

wherein R1 and R2 independently represent an optionally substituted alkyl group having 1 to 6 carbon atoms or R1 and R2 together with the carbon atom to which they are bound form an optionally substituted cycloalkyl group having 3 to 10 carbon atoms, X represents a halogen atom, optionally substituted alkyl group having 1 to 6 carbon atoms or optionally substituted alkoxy group having 1 to 6 carbon atoms, n represents an integer of 0 to 4, Y represents a halogen atom, optionally substituted alkyl group having 1 to 6 carbon atoms or optionally substituted alkoxy group having 1 to 6 carbon atoms, and m represents an integer of 0 to 4, comprising reacting a compound represented by formula (3):

wherein R1, R2, X and n are the same as previously defined, with a compound represented by formula (4):

wherein Y and m are the same as previously defined, in the presence of an acid.

14. The method for producing a compound represented by formula (1) described in claim 13 , wherein R1 and R2 independently represent an optionally substituted alkyl group having 1 to 6 carbon atoms.

15. The method for producing a compound represented by formula (1) described in claim 14 , wherein n is 0.

16. The method for producing a compound represented by formula (1) described in claim 13 , wherein a compound represented by formula (3) is obtained by hydrolyzing a salt containing a compound represented by formula (5):

wherein R1, R2, X and n are the same as in claims 13 and R3 represents an alkyl group having 1 to 3 carbon atoms.

17. The method for producing a compound represented by formula (1) described in claim 16 , wherein R1 and R2 independently represent an optionally substituted alkyl group having 1 to 6 carbon atoms.

18. The method for producing a compound represented by formula (1) described in claim 17 , wherein n is 0.

19. The method for producing a compound represented by formula (1) described in claim 16 , wherein a salt containing a compound represented by formula (5) is obtained by reacting a compound represented by formula (6):

wherein R1, R2, X and n are the same as in claim 16 , with a salt containing a compound represented by formula (7):

wherein R3 is the same as in claim 16 and Z represents a halogen atom.

20. The method for producing a compound represented by formula (1) described in claim 19 , wherein R1 and R2 independently represent an optionally substituted alkyl group having 1 to 6 carbon atoms.

21. The method for producing a compound represented by formula (1) described in claim 20 , wherein n is 0.