Process for preparing optically active 2,3-bisphosphino-substituted quinoxalines
AssigneeNippon Chemical Industrial Co., Ltd.
InventorTsuneo Imamoto
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Abstract
There is provided a method for producing a 2,3-bisphosphinopyrazine derivative, the method comprising a first step of adding a base to a liquid comprising: 2,3-dihalogenopyrazine represented by the following general formula (1); a hydrogen-phosphine borane compound represented by the following general formula (2); and a deboranating agent, and allowing the resultant to react to thereby obtain the 2,3-bisphosphinopyrazine derivative represented by the following general formula (3). According to the present invention, a method for producing the industrially advantageous 2,3-bisphosphinopyrazine derivative can be provided.
Claims4
A process for preparing a compound represented by formula (3):
- wherein:
- each R1 independently represents F, Cl, Br, I, C1-5 alkyl, NH2, NO2, or OH;
- each R2 independently represents CH3, CH2CH3, CH(CH3)2, (CH2)2CH3, CH2CH(CH3)2, CH(CH3)CH2CH3, C(CH3)3, (CH2)5CH3, (CH2)3CH(CH3)2, (CH2)6CH3, (CH2)4CH(CH3)2, cycloalkyl, adamantyl, or phenyl;
- each R3 independently represents CH3, CH2CH3, CH(CH3)2, (CH2)2CH3, CH2CH(CH3)2, CH(CH3)CH2CH3, C(CH3)3, (CH2)5CH3, (CH2)3CH(CH3)2, (CH2)6CH3, (CH2)4CH(CH3)2, cycloalkyl, adamantyl, or phenyl;
- and
- n represents 0;
- comprising the following step of:
- adding potassium tert-butoxide to a solution comprising:
- (i) a compound represented by formula (1):
- wherein:
- each X independently represents Cl, Br, or I;
- each R1 independently represents F, Cl, Br, I, C1-5 alkyl, NH2, NO2, or OH;
- and
- n represents 0;
- (ii) a compound represented by formula (2):
- wherein:
- R2 represents CH3, CH2CH3, CH(CH3)2, (CH2)2CH3, CH2CH(CH3)2, CH(CH3)CH2CH3, C(CH3)3, (CH2)5CH3, (CH2)3CH(CH3)2, (CH2)6CH3, (CH2)4CH(CH3)2, cycloalkyl, adamantyl, or phenyl;
- and
- R3 represents CH3, CH2CH3, CH(CH3)2, (CH2)2CH3, CH2CH(CH3)2, CH(CH3)CH2CH3, C(CH3)3, (CH2)5CH3, (CH2)3CH(CH3)2, (CH2)6CH3, (CH2)4CH(CH3)2, cycloalkyl, adamantyl, or phenyl;
- (iii) a liquid solvent selected from the group consisting of tetrahydrofuran, N,N-dimethylformamide, cyclopentyl methyl ether, diethyl ether, dibutyl ether, dioxane, hexane, and toluene, or a combination thereof;
- and
- (iv) a deboronating agent selected from the group consisting of N,N,N′,N′-tetramethylethylenediamine, triethylenediamine, and triethylamine.
Dependencies are inferred from the claim text.