Optically active 1,4-benzodioxin-2-carboxylic acid derivatives and process for producing the same

A process for preparing a compound of formula (1) 38

• wherein R is as defined below and a compound of formula (2) 39
• wherein R is as defined below, which comprises the steps of;
• reacting a racemate of formula (3) 40
• wherein R is (R)-1-phenylethylamino or (S)-1-phenylethylamino with an acylating agent in the presence of a hydrolase to give a compound of formula (4) 41
• wherein R is as defined above and X is (C1-C4)acyl and a compound of formula (2) 42
• wherein R is as defined above, followed by separation, and subjecting a compound of formula (4) to alcoholysis or hydrolysis.

A process for preparing a compound of formula (7) 43

• wherein R, R2 and R3 are as defined below, which comprises the steps of;
• reacting the compound of formula (1) 44
• wherein R is (R)-1-phenylethylamino or (S)-1-phenylethylamino with a halogenating agent or a sulfonylating agent, and
• condensing the resulting compound of formula (5) 45
• wherein R is as defined above and Y is halogen, (C1-C4)alkylsulfonyloxy or arylsulfonyloxy with a compound of formula (6) 46
• wherein R2 and R3 may be the same or different, and each is hydrogen, halogen, (C1-C6)alkyl, trifluoromethyl, (C1-C6)alkoxy, aryl, aryloxy or aryl(C1-C6)alkyloxy, the aryl, aryloxy or aryl(C1-C6)alkyloxy being optionally substituted by one or two halogen atoms, or R2 and R3 together may form —OCH2O—.

A process for preparing a compound of formula (7) 47

• wherein R, R2 and R3 are as defined below, which comprises the steps of:
• reacting the compound of formula (2) 48
• wherein R is (R)-1-phenylethylamino or (S)-1-phenylethylamino with a halogenating agent or a sulfonylating agent, and
• condensing the resulting compound of formula (5) 49
• wherein R is as defined above and Y is halogen, (C1-C4)alkylsulfonyloxy or arylsulfonyloxy with the compound of formula (6) 50
• wherein R2 and R3 may be the same or different, and each is hydrogen, halogen, (C1-C6)alkyl, trifluoromethyl, (C1-C6)alkoxy, aryl, aryloxy or aryl(C1-C6)alkyloxy, the aryl, aryloxy or aryl(C1-C6)alkyloxy being optionally substituted by one or two halogen atoms, or R2 and R3 together may form —OCH2O—.