Production of 2,2,4,4-tetramethylcyclobutane-1,3-diol from isobutanol using a homogeneous catalyst

A process for producing 2,2,4,4-tetramethylcyclobutane-1,3-diol comprising:

• (1) contacting 2,2,4,4-tetramethylcyclobutanedione with isobutanol in the presence of a tandem ruthenium transfer hydrogenation and Tischenko reaction catalyst comprising one or more of H2Ru(PPh3)4, Ru3(CO)12, (Ar4C4CO)Ru(CO)3, and (Ar4C4CO)2H(μ-H) (CO)4Ru2, to produce isobutyl isobutyrate and 2,2,4,4-tetramethylcyclobutane-1,3-diol and 3-hydroxy-2,2,4,4-tetramethylcyclobutanone,
• wherein (Ar4C4CO)Ru(CO)3 is represented by the general formula:
• and Ar is represented by the general formula:
• and the groups R are the same or different and are selected from H, methyl, ethyl, or a linear or branched alkyl group containing from 3 to 10 carbon atoms, substituted or unsubstituted aromatic group, an aldehyde, a ketone or an ester with 2-10 carbon atoms, trifluoromethyl or a fluorinated hydrocarbon group;
• and wherein (Ar4C4CO)2H(μ-H)(CO)4Ru2 is represented by the general formula:
• and Ar is represented by the general formula:
• and the groups R are the same or different and are selected from H, methyl, ethyl, or a linear or branched alkyl group containing from 3 to 10 carbon atoms, substituted or unsubstituted aromatic group, an aldehyde, a ketone or an ester with 2-10 carbon atoms, trifluoromethyl or a fluorinated hydrocarbon group;
• (2) optionally hydrogenating any unreacted 2,2,4,4-tetramethylcyclobutanedione and 3-hydroxy-2,2,4,4-tetramethylcyclobutanone to produce 2,2,4,4-tetramethylcyclobutane-1,3-diol;
• (3) hydrolyzing the isobutyl isobutyrate optionally in the presence of an acid catalyst to produce isobutyric acid and isobutanol, and optionally wherein the isobutanol is optionally recycled to step (1);
• (4) converting the isobutyric acid to 2,2,4,4-tetramethylcyclobutanedione, wherein the 2,2,4,4-tetramethylcyclobutanedione is optionally recycled to step (1).

A process for the producing 2,2,4,4-tetramethylcyclobutane-1,3-diol comprising:

• (1) contacting 2,2,4,4-tetramethylcyclobutanedione with isobutanol in the presence of a tandem ruthenium transfer hydrogenation and Tischenko reaction catalyst selected from ((Ph4C4CO)2H(μ-H)(CO)4Ru2)-(Ph4C4CO)2H(μ-H)(CO)4Ru2, [(4-ClC6H4)4C4CO]2H(μ-H)(CO)4Ru2, [2,5-(C6H5)2-3,4-(4-MeOC6H4)2C4CO]2H(μ-H)(CO)4Ru2, or [2,5-(C6H5)2-3,4-(4-FC6H4)2C4CO]2H(μ-H)(CO)4Ru2 to produce isobutyl isobutyrate and 2,2,4,4-tetramethylcyclobutane-1,3-diol and 3-hydroxy-2,2,4,4-tetramethylcyclobutanone;
• (2) optionally hydrogenating any unreacted 2,2,4,4-tetramethylcyclobutanedione and 3-hydroxy-2,2,4,4-tetramethylcyclobutanone to produce 2,2,4,4-tetramethylcyclobutane-1,3-diol;
• (3) hydrolyzing the isobutyl isobutyrate optionally in the presence of an acid catalyst to produce isobutyric acid and isobutanol, and optionally wherein the isobutanol is optionally recycled to step (1);
• (4) converting the isobutyric acid to 2,2,4,4-tetramethylcyclobutanedione, wherein the 2,2,4,4-tetramethylcyclobutanedione is optionally recycled to step (1).

A process for producing 2,2,4,4-tetramethylcyclobutane-1,3-diol with bio-content comprising:

• (1) contacting 2,2,4,4-tetramethylcyclobutanedione with isobutanol comprising bio-isobutanol in the presence of a tandem transfer hydrogenation and Tischenko reaction catalyst to produce bio-isobutyl isobutyrate and bio-2,2,4,4-tetramethylcyclobutane-1,3-diol and bio-3-hydroxy-2,2,4,4-tetramethylcyclobutanone;
• (2) optionally hydrogenating any unreacted bio-2,2,4,4-tetramethylcyclobutanedione and bio-3-hydroxy-2,2,4,4-tetramethylcyclobutanone to produce bio-2,2,4,4-tetramethylcyclobutane-1,3-diol;
• (3) hydrolyzing the bio-isobutyl isobutyrate optionally in the presence of an acid catalyst to produce bio-isobutyric acid and bio-isobutanol, and optionally wherein the produced bio-isobutanol is optionally recycled to step (1);
• (4) converting the bio-isobutyric acid to bio-2,2,4,4-tetramethylcyclobutanedione wherein the bio-2,2,4,4-tetramethylcyclobutanedione is optionally recycled to step (1).