| 摘要 |
A process for preparing a cyclic ester or a cyclic amide includes contacting hydroxycarboxylic acid and/or amino-carboxylic acid, an ester thereof, or a salt thereof, with acidic zeolite. The hydroxycarboxylic acid is a 2- or 6-hydroxycarboxylic acid, and the amino carboxylic acid is a 2- or 6-amino-carboxylic acid. The zeolite may include two or three interconnected and non-parallel channel systems, in which a channel system includes 10- or more-membered ring channels, and in which a framework Si/X2 ratio is at least 24 as measured by NMR. X is Al or B. The zeolite may include three interconnected and non-parallel channel systems, in which at least two channel systems include 10- or more-membered ring channels, and in which a framework Si/X2 ratio is at least 6 as measured by NMR. The process may be performed at a pressure between 0.5 and 20 bar. |
| 主权项 |
1. A process for preparing a compound, comprising:
contacting at least one hydroxycarboxylic acid; or an ester, or salt thereof; wherein said hydroxycarboxylic acid is a 2-hydroxycarboxylic acid comprising the formula (Ia); or a salt, or ester thereof; wherein R5 is OH or NH2; and R1 and R2 are each independently hydrogen or a group selected from a C1-6 alkyl, a C2-6 alkenyl, a C6-10 aryl, a C1-10 alkylC6-10 arylene, a C6-10 arylC1-6 alkylene, or a C2-6alkynyl; each group being optionally substituted by one or more substituents selected from a C1-6 alkyl, a C1-6 alkyloxy, or a 6-hydroxycarboxylic acid, wherein the 6-hydroxycarboxylic acid comprises a 6-hydroxyhexanoic acid, optionally substituted with one or more groups selected from the group consisting of a halogen, a C1-4alkyl, a C2-4alkenyl, or a C2-4alkynyl; with at least one acidic zeolite comprising:
two or three interconnected and non-parallel channel systems, wherein at least one of said channel systems comprises 10- or more-membered ring channels; and a framework Si/X2 ratio of at least 24 as measured by NMR; orthree interconnected and non-parallel channel systems, wherein at least two of said channel systems comprise 10-or more-membered ring channels; and a framework Si/X2 ratio of at least 8 as measured by NMR; wherein each X is Al or B, wherein the process is performed at a pressure between 0.5 and 20 bar, and wherein said compound is a cyclic ester of formula (II): wherein Z1 is O, wherein Z2 is O; and wherein R1 and R2 are each independently hydrogen or a group selected from C1-6 alkyl; C2-6 alkenyl; C6-10 aryl; C1-10alkylC6-10arylene; C6-10arylC1-6alkylene; or C2-6alkynyl; each group being optionally substituted by one or more substituents selected from C1-6alkyl, C1-6alkyloxy. |
