Method for producing 3,4-dihydroisoquinoline derivatives and production intermediates of same
View Patent ↗Provided are an efficient method for producing 3,4-dihydroisoquinoline derivatives and useful production intermediates thereof. Provided is a method for producing 3,4-dihydroisoquinoline derivatives represented by general formula (1), comprising converting a compound represented by general formula (3) in the presence of acid after reacting with an aniline derivative, or converting a compound represented by general formula (3) by reacting with an aniline derivative in the presence of an acid.
1. A compound represented by formula (3):
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, and
n represents an integer of 0 to 4.
2. The compound represented by formula (3) according to claim 1 , wherein R1 and R2 independently represent an optionally substituted alkyl group having 1 to 6 carbon atoms.
3. The compound represented by formula (3) according to claim 2 , wherein n is 0.
4. A method for producing a compound represented by formula (3) as defined in claim 1 : comprising hydrolyzing a salt containing a compound represented by formula (5):
wherein R1, R2, X and n are the same as previously defined, and
R3 is an alkyl group having 1 to 3 carbon atoms,
to obtain the compound represented by formula (3).
5. The method for producing a compound represented by formula (3) according to 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 (3) according to claim 5 , wherein n is 0.