Method for producing 4, 4-difluoro-3,4-dihydroisoquinoline derivatives

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

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

wherein R1, R2, X, Y, n and m are the same as previously defined, with hydrogen fluoride.

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

wherein R1, R2, X, Y, n and m are the same as in claim 1 , with a brominating agent.

3. The method for producing a compound represented by general formula (1) described in claim 1 , wherein R1 and R2 independently represent an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, n=0 and m=0.

4. The method for producing a compound represented by general formula (1) described in claim 2 , wherein R1 and R2 independently represent an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, n=0 and m=0.