Processes for the synthesis of tertiary amines
The invention provides processes for the preparation of morphinans having a tertiary amine. In particular, the present invention provides processes for the formation of tertiary amine alkaloids by direct N-alkylation of secondary amine alkaloids, the processes co-mediated by an alkylating agent and a protic solvent or a mixture of a protic solvent and an aprotic solvent.
1. A process for the preparation of a compound comprising Formula (II) from a compound comprising Formula (I) according to the following reaction:
wherein:
the alkylating agent is selected from the group consisting of alkyl halide represented by the formula R 17 X, and dialkyl sulfate represented by the formula R 17 2 SO 4 , wherein R 17 is selected from the group consisting of hydrocarbyl and substituted hydrocarbyl, and X is selected from the group consisting of Cl, Br and I;
R 1 , R 2 , R 3 , and R 4 are independently selected from the group consisting of hydrogen, halogen, hydroxyl, SH, —SR 1611 , —OR 1611 , and —NR 1611 R 1612 ; hydrocarbyl, and substituted hydrocarbyl;
R 5a , R 5b , R 6a , R 6b , R 7a , R 7b , R 8a R 8b , R 9 , R 10a R 10b , R 15a R 15b , R 16a R 16b , and R 14 are independently selected from the group consisting of hydrogen, halogen, hydroxyl, SH, —SR 1611 , —OR 1611 , and —NR 1611 R 1613 ; hydrocarbyl, and substituted hydrocarbyl, wherein any pair of R #a and R #b wherein # is any one of 5, 6, 7, 8, 9, 10, 15, 16, optionally together form a group selected from the group consisting of ═O, ═S, and ═NR 1613 ;
R 1611 , R 1612 and R 1613 are independently selected from the group consisting of hydrocarbyl, and substituted hydrocarbyl;
provided that one or more of R 1 , R 2 , R 3 , R 4 , R 5a , R 5b , R 6a , R 6b , R 7a , R 7b , R 8a R 8b , R 9a , R 10a R 10b , R 15a R 15b , R 16a R 16b , and R 14 may come together to form one or more carbocyclic or heterocyclic rings.
2. The process of claim 1 , wherein the alkylating agent is selected from the group consisting of an alkyl halide having from one to ten carbon atoms, and a substituted alkyl halide having from one to ten carbon atoms; and the protic solvent is selected from the group consisting of water, alcohol, inorganic acid and organic acid.
3. The process of claim 1 , further comprising conducting the reaction in the presence of an agent selected from the group consisting of a proton acceptor; an aprotic solvent; a metal halide represented by the formula MX n , wherein M is selected from the group consisting of Li, Na, K, Cs, Mg, Ca, and Ba, X is selected from the group consisting of Cl, Br and I, and n=1 or 2; and combinations thereof.
4. The process of claim 1 , wherein the mole-to-mole ratio of the alkylating agent to protic solvent to compound comprising Formula (I) is from about 1:0.2:1 to about 2:5:1; the reaction is conducted in the presence of a proton acceptor; and the reaction is conducted at a temperature ranging from about 30° C. to about 85° C.
5. The process of claim 1 , wherein the compounds comprising Formula (I) and (II) are (+) enantiomers, (−) enantiomers, and combinations of both; and the configuration of C-9, C-13, and C-14, respectively, in the compounds comprising Formula (I) and (II) is selected from the group consisting of RRR, RRS, RSR, RSS, SRR, SRS, SSR, and SSS, provided, however, that the C-15 and C-16 atoms are either both on the alpha face of the compound or the beta face of the compound.
6. The process of claim 1 , wherein the formation of compounds comprising tertiary amines at position C-17 and compounds alkylated at R 3 when it comprises oxygen together comprise less than 2% by weight of the total compounds formed by the reaction.
7. The process of claim 1 , wherein the yield of the compound comprising Formula (II) is greater than 90%.
8. A process for the preparation of a compound comprising Formula (IIa) from a compound comprising Formula (Ia) according to the following reaction:
wherein:
the alkylating agent is selected from the group consisting of alkyl halide represented by the formula R 17 X, and dialkyl sulfate represented by the formula R 17 2 SO 4 , wherein R 17 is selected from the group consisting of hydrocarbyl and substituted hydrocarbyl, and X is selected from the group consisting of Cl, Br and I;
A is a heteroatom selected from oxygen and sulfur;
R 1 , R 2 , R 3 , and R 4 are independently selected from the group consisting of hydrogen, halogen, hydroxyl, SH, —SR 1611 , —OR 1611 , and —NR 1611 R 1612 ; hydrocarbyl, and substituted hydrocarbyl;
R 5 , R 6a , R 6b , R 7a , R 7b , R 8a R 8b , R 9 , R 10a R 10b , R 15a R 15b , R 16a R 16b , and R 14 are independently selected from the group consisting of hydrogen, halogen, hydroxyl, SH, —SR 1611 , —OR 1611 , and —NR 1611 R 1613 ; hydrocarbyl, and substituted hydrocarbyl, wherein any pair of R #a and R #b wherein # is any one of 6, 7, 8, 9, 10, 15, 16, optionally together form a group selected from the group consisting of ═O, ═S, and ═NR 1613 ;
R 1611 , R 1612 and R 1613 are independently selected from the group consisting of hydrocarbyl, and substituted hydrocarbyl;
provided that one or more of R 1 , R 2 , R 3 , R 4 , R 5 , R 6a , R 6b , R 7a , R 7b , R 8a R 8b , R 9a , R 10a R 10b , R 15a R 15b , R 16a R 16b , and R 14 may come together to form one or more carbocyclic or heterocyclic rings.
9. The process of claim 8 , wherein the alkylating agent is selected from the group consisting an alkyl halide having from one to ten carbon atoms, and a substituted alkyl halide having from one to ten carbon atoms; and the protic solvent is selected from the group consisting of water, alcohol, inorganic acid and organic acid.
10. The process of claim 8 , further comprising conducting the reaction in the presence of an agent selected from the group consisting of a proton acceptor; an aprotic solvent; a metal halide represented by the formula MX n , wherein M is selected from the group consisting of Li, Na, K, Cs, Mg, Ca, and Ba, X is selected from the group consisting of Cl, Br and I, and n=1 or 2; and combinations thereof.
11. The process of claim 8 , wherein the mole-to-mole ratio of the alkylating agent to protic solvent to compound comprising Formula (Ia) is from about 1:0.2:1 to about 2:5:1; the reaction is conducted in the presence of a proton acceptor; and the reaction is conducted at a temperature ranging from about 30° C. to about 85° C.
12. The process of claim 8 , wherein the compounds comprising Formula (Ia) and (IIa) are (+) enantiomers; (−) enantiomers; and combinations of both; and the configuration of C-5, C-9, C-13, and C-14, respectively, in the compounds comprising Formula (Ia) and (IIa) is selected from the group consisting of RRRR, RRSR, RRRS, RRSS, RSRR, RSSR, RSRS, RSSS, SRRR, SRSR, SRRS, SRSS, SSRR, SSSR, SSRS, and SSSS, provided, however, that the C-15 and C-16 atoms are either both on the alpha face of the compound or the beta face of the compound.
13. The process of claim 8 , wherein the formation of compounds comprising tertiary amines at position C-17 and compounds alkylated at R 3 when it comprises oxygen together comprise less than 2% by weight of the total compounds formed by the reaction.
14. The process of claim 8 , wherein the yield of the compound comprising Formula (IIa) is greater than 90%.
15. The process of claim 8 , wherein the process comprises the preparation of a compound comprising Formula (IIa-2) from a compound comprising Formula (Ia-1) according to the following reaction:
wherein the alkylating agent is selected from the group consisting an alkyl halide having from one to ten carbon atoms, and a substituted alkyl halide having from one to ten carbon atoms; and the protic solvent is selected from the group consisting of water, alcohol, inorganic acid and organic acid.
16. The process of claim 8 , wherein the process comprises the preparation of a compound comprising Formula (IIb-2) from a compound comprising Formula (Ib-1) according to the following reaction:
17. The process of claim 16 , wherein the compounds comprising Formula (Ib-1) and (IIb-2) are (+) enantiomers; and the formation of compounds comprising Formula (IIb-3) and (IIb-4) together comprise less than 2% by weight of the total compounds formed by the reaction:
18. The process of claim 16 , wherein the compounds comprising Formula (Ib-1) and (IIb-2) are (−) enantiomers; and the formation of compounds comprising Formula (IIb-5) and (IIb-6) together comprise less than 2% by weight of the total compounds formed by the reaction:
19. The process of claim 8 , wherein the process comprises the preparation of a compound comprising Formula (IIc-2) from a compound comprising Formula (Ic-1) according to the following reaction:
wherein the alkylating agent is selected from the group consisting an alkyl halide having from one to ten carbon atoms, and a substituted alkyl halide having from one to ten carbon atoms; and the protic solvent is selected from the group consisting of water, alcohol, inorganic acid and organic acid.
20. The process of claim 19 , wherein the formation of compounds comprising tertiary amines at position C-17 and compounds that are alkylated at position C-3 together comprise less than 2% by weight of the total compounds formed by the reaction.
21. The process of claim 8 , wherein the process comprises the preparation of a compound comprising Formula (IId-2) from a compound comprising Formula (Id-1) according to the following reaction:
22. The process of claim 21 , wherein the formation of compounds comprising tertiary amines at position C-17 and compounds that are alkylated at position C-3 together comprise less than 2% by weight of the total compounds formed by the reaction.