Synthesis of 2-hydroxy-n,n-dimethyl-3-[[2-[[1(r)-(5-methyl-2-furanyl)propyl]amino]-3,4-dioxo-1-cyclobuten-1-yl]amino]benzamide
Disclosed is a process for making the compound of formula I: using the compounds of formulas II, Q, and XI or XII: wherein A is selected from the group consisting of Br, Cl and I (with Br being preferred); and R represents (C 1 -C 10 )alkyl. Also disclosed are intermediate compounds that are made in the disclosed process.
1. A process for making a compound of formula V, said process comprising:
(a) converting the compound of formula II
to a compound of formula IV:
wherein A, in the compounds of formulas II and IV, is selected from the group consisting of Br, Cl and I;
(b) hydrogenating the compound of formula IV with a suitable hydrogenation catalyst under hydrogen pressure, to form the intermediate compound of formula IV(i):
(c) reacting the compound of formula IV(i) with a compound of formula Q:
wherein R represents (C 1 -C 10 )alkyl, to yield a compound of formula V.
2. The process of claim 1 wherein substituent A is Br.
3. The process of claim 1 wherein step (a) comprises reacting said compound of formula II with a suitable acid chloride in a suitable solvent at a suitable temperature, and then reacting the resulting reaction mixture with dimethylamine.
4. The process of claim 1 , wherein step (b) comprises making a mixture of said compound of formula IV, a hydrogenation catalyst, and a suitable base, and pressurizing the mixture under H 2 pressure.
5. The process of claim 1 wherein step (c) comprises adding 3,4-dialkoxy-3-cyclobutene-1,2-dione to said compound of formula IV(i) from step (b). adjusting the temperature to about 0° C. to about 80° C. to yield a compound of formula V.
6. The process of claim 1 wherein step (c) further comprises adding a base to the compound of formula IV(i), wherein said base is selected from the group consisting of: KOH, NaOH, Na 2 CO 3 , K 2 CO 3 , NaHCO 3 , KHCO 3 , tetramethylguanidine, DBU, diisopropylethylamine and mixtures thereof.
7. The process of claim 1 wherein:
(1) said substituent A is Br;
(2) step (a) comprises reacting said compound of formula II with a suitable acid chloride in a suitable solvent at a suitable temperature, and then reacting the resulting reaction mixture with dimethylamine;
said solvent used with said acid chloride is selected from the group consisting of: acetonitrile, THF, t-butylmethylether, methylenechloride, toluene, ethylacetate, diethylether, and chloroform; said acid chloride is selected from the group consisting of: thionyl chloride and oxalyl chloride; and said dimethylamine is dimethylamine gas or a solution of dimethylamine wherein the solvent used in said dimethylamine solution is selected from the group consisting of: acetonitrile, THF, t-butylmethylether, methylenechloride, toluene, ethylacetate, diethylether, and chloroform;
(3) step (b) comprises making a mixture of said compound of formula IV, a hydrogenation catalyst, and a suitable base, and pressurizing the mixture under H 2 pressure; said suitable base is selected from the group consisting of: KOH, NaOH, Na 2 CO 3 , K 2 CO 3 , NaHCO 3 , KHCO 3 , tetramethylguanidine, DBU, diisopropylethylamine and mixtures thereof; and said hydrogenation catalyst is selected from the group consisting of: Pd/C, Pt/C, PdOH, and raney nickel; and
(4) step (c) comprises adding 3,4-dialkoxy-3-cyclobutene-1,2-dione to said compound of formula IV(i) from step (b), adjusting the temperature to about 0° C. to about 80° C. to yield a compound of formula V; said 3,4-dialkoxy-3-cyclobutene-1,2-dione is 3,4-diethoxy-3-cyclobutene-1,2-dione.
8. The process of claim 7 wherein:
(1) said acid chloride in step (a) is thionyl chloride;
(2) said solvent used with said acid chloride in step (a) is acetonitrile; and
(3) said hydrogenation catalyst in step (b) is Pd/C.
9. The process of claim 8 wherein step (c) further comprises adding a base to the compound of formula IV(i), wherein said base is selected from the group consisting of: KOH, NaOH, Na 2 CO 3 , K 2 CO 3 , NaHCO 3 , KHCO 3 , tetramethylguanidine, DBU, diisopropylethylamine and mixtures thereof.
10. The process of claim 9 wherein:
(1) said dimethlyamine in step (a) is at a concentration of at least 1 molar equivalent with respect to said compound of formula II;
(2) said H 2 pressure in step (b) is from about 10 to about 500 psi; and
(3) said 3,4-diethalkoxy-3-cyclobutene-1,2-dione in step (c) is at least 1 molar equivalent with respect to the compound of formula IV(i).
11. The process of claim 10 wherein step (c) further comprises adding a base to the compound of formula IV(i), wherein said base is selected from the group consisting of: KOH, NaOH, Na 2 CO 3 , K 2 CO 3 , NaHCO 3 , KHCO 3 , tetramethylguanidine, DBU, diisopropylethylamine and mixtures thereof.