Methods for producing phenylalanine derivatives having a quinazolinedione skeleton and intermediates for production thereof
The present invention provides a method for producing a phenylalanine derivative(s) having a quinazolinedione ring of formula (5), including steps comprising of reacting an acylphenylalanine derivative(s) of formula (1) with a carbonyl group-introducing reagent(s) and a derivative(s) of anthranilic acid to form an asymmetric urea intermediate(s); making the asymmetric urea intermediate(s) into a quinazolinedione compound(s) of formula (4) in the presence of a base(s); and N-alkylating quinazolinedione ring amide of the obtained quinazolinedione compounds with N-alkylation agents. This production method is an industrially applicable method for producing phenylalanine derivatives having a quinazolinedione skeleton, which are compounds highly useful as drugs having α 4 integrin inhibiting activity. In the formulae (1) and (5), R1 represents a phenyl group having a substituent(s) and the like, R2 represents an alkyl group and the like, R3 represents a dialkylamino group and the like, and R4 represents an alkyl group and the like.
1. A method for producing a phenylalanine derivative(s) having a quinazolinedione ring of the following formula (5), comprising steps of
reacting an acylphenylalanine derivative(s) of formula (1):
wherein R1 represents a phenyl group which may have a substituent(s) or a pyridyl group which may have a substituent(s), R2 represents an alkyl group which may have a substituent(s), and the derivative(s) is in a salt(s) with chemically acceptable acid(s) or free form(s),
with a carbonyl group-introducing reagent(s) and an anthranilic acid derivative(s) of formula (2):
wherein R3 represents a dialkylamino group; R4 represents a hydrogen atom, an alkyl group or a benzyl group which may have a substituent(s); and R5 represents an alkyl group or an alkylcarbonyl group, and the derivative(s) is in a salt(s) with chemically acceptable acid(s) or free form(s),
to form an asymmetric urea intermediate(s) of formula (3):
wherein R1 to R5 are defined above;
making the asymmetric urea intermediate(s) into a quinazolinedione compound(s) of formula (4) in the presence of a base(s):
wherein R1 to R4 are defined above; and
when R4 represents a hydrogen atom in the obtained quinazolinedione compound(s) of the formula (4), N-alkylating a quinazolinedione ring amide of the quinazolinedione compound(s) with an N-alkylation agent(s) to form the phenylalanine derivative(s) having a quinazolinedione skeleton of formula (5):
wherein R1 to R3 are defined above, R4 represents an alkyl group or a benzyl group which may have a substituent(s).
2. The production method according to claim 1 , wherein the carbonyl group-introducing reagent is 1,1′-carbonyldiimidazole or chloroformate.
3. The production method according to claim 1 , wherein the base(s) represents a potassium carbonate or a sodium methoxide.
4. The production method according to claim 1 , wherein the N-alkylation agent is methyl p-toluenesulfonate.
5. The production method according to claim 1 , comprising steps of reacting a carbonyl group-introducing reagent selected from the group consisting of 1,1′-carbonyldiimidazole and chloroformate and the compound of the formula (2) wherein R3 represents a dimethylamino group, R4 represents a hydrogen atom and R5 represents a methyl group with the compound of the formula (1) wherein R1 represents a 2,6-dichlorophenyl group and R2 represents a methyl group to obtain methylester of 2-(3-{4-[2-(2,6-dichlorobenzoylamino)-2-methoxycarbonylethyl]phenyl}ureide)-5-dimethylaminobenzoic acid; converting it in the presence of potassium carbonate or sodium methoxide into methylester of N α -(2,6-dichlorobenzoyl)-4-(6-dimethylamino-2,4[1H,3H]-quinazolinedione-3-yl)-L-phenylalanine of the formula (4); and then N-alkylating it with methyl p-toluenesulfonate to obtain methylester of N α -(2,6-dichlorobenzoyl)-4-(1-methyl-6-dimethylamino-2,4[1H,3H]-quinazolinedione-3-yl)-L-phenylalanine.
6. The production method according to claim 1 comprising steps of reacting a carbonyl group-introducing reagent selected from the group consisting of 1,1′-carbonyldiimidazole and chloroformate and the compound of the formula (2) wherein R3 represents a dimethylamino group, R4 represents a methyl group and R5 represents a methyl group with the compound of the formula (1) wherein R1 represents a 2,6-dichlorophenyl group and R2 represents a methyl group to obtain the compound of the formula (3);
converting it in the presence of potassium carbonate or sodium methoxide into methylester of N α -(2,6-dichlorobenzoyl)-4-(1-methyl-6-dimethylamino-2,4[1H,3H]-quinazolinedione-3-yl)-L-phenylalanine.