Process for producing novel 4-benzoazonine derivatives

A process for producing the 4-benzoazonine compound represented by the formula (11) or a salt thereof, comprising

• (g):
• a step where a tetrahydroazepine compound represented by the formula (10) or a salt thereof is made to react with an acid,
• wherein in the formulae,
• R1 is an alkyl group optionally substituted with halogen atom, aryl group, alkoxy group, allyl group or vinyl group,
• R2 is an alkyl group optionally substituted with halogen atom, aryl group, alkoxy group, allyl group or vinyl group and
• one of the X—Y bond and the Y—Z bond is a carbon-carbon double bond and the other is a carbon-carbon single bond.

A process for producing a compound represented by the formula (13) or a salt thereof, comprising:

• (a):
• a step where a compound represented by the formula (4) or a salt thereof is made to react with an alkylating agent to give a compound represented by the formula (5) or a salt thereof,
• wherein in the formulae,
• R2 is an alkyl group optionally substituted with halogen atom, aryl group, alkoxy group, allyl group or vinyl group and
• the two R3's are the same or different, and each is an alkyl group optionally substituted with halogen atom, aryl group, alkoxy group, allyl group or vinyl group, or the two R3's may be bonded to each other to form a ring together with oxygen atoms to which the two R3's are bonded;
• (b):
• a step where a compound represented by the formula (5) or a salt thereof is made to react with a compound represented by the formula (15) to give a compound represented by the formula (6) or a salt thereof,
• wherein in the formulae, R1 is an alkyl group optionally substituted with halogen atom, aryl group, alkoxy group, allyl group or vinyl group, R2 and R3 have the same meanings as mentioned in the step (a) and A is an eliminating group;
• (c):
• a step where a compound represented by the formula (6) or a salt thereof is made to react with a reducing agent to give a compound represented by the formula (7) or a salt thereof,
• wherein in the formulae, R1 has the same meaning as mentioned in the step (b), R2 and R3 have the same meanings as mentioned in the step (a);
• (d):
• a step where a compound represented by the formula (7) or a salt thereof is made to react with an acid to give a compound represented by the formula (8) or a salt thereof,
• wherein in the formulae, R1 has the same meaning as mentioned in the step (b), and R2 and R3 have the same meanings as mentioned in the step (a);
• (e):
• a step where a compound represented by the formula (8) or a salt thereof is made to react with a methylating agent to give a compound represented by the formula (9) or a salt thereof,
• wherein in the formulae, R1 has the same meaning as mentioned in the step (b), and R2 has the same meaning as mentioned in the step (a);
• (f):
• a step where a compound represented by the formula (9) or a salt thereof is made to react with at least one dehydrating agent selected from the group consisting of boron trifluoride ether complex, trifluoroacetic acid, trifluoroacetic acid anhydride, trimethylsilyl trifluoromethanesulfonate, aluminum chloride, titanium (IV) chloride, tin (IV) chloride, triphenylmethyl perchlorate, bismuth triflate, ytterbium triflate, scandium triflate, trifluoromethanesulfonic acid, methanesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, 10-camphorsulfonic acid and phosphorus pentaoxide,
• wherein in the formulae, R1 has the same meaning as mentioned in the step (b), and R2 has the same meaning as mentioned in the step (a) and
• one of the X—Y bond and the Y—Z bond is a carbon-carbon double bond and the other is a carbon-carbon single bond
• (g):
• a step where a tetrahydroazepine compound represented by the formula (10) or a salt thereof is made to react with an acid,
• wherein in the formulae, R1 has the same meaning as mentioned in the step (b), and R2 has the same meaning as mentioned in the step (a) and the X—Y bond and the Y—Z bond have the same meanings as mentioned in step (f),
• (h):
• a step where a 4-benzoazonine compound represented by the formula (11) or a salt thereof is made to react with an organic acid to give a compound represented by the formula (12) or salt thereof and
• (i) a step where an OR1 group in the compound represented by the formula (12) or a salt thereof is deprotected to give the compound represented by the formula (13) or a salt thereof,
• wherein in the formulae, R1 has the same meaning as mentioned in the step (b), and R2 has the same meaning as mentioned in the step (a).