Preparation of o,o'-dihydroxyazobenzenes from o-nitrophenols
AssigneePhillips Petroleum Company
InventorTimothy P. Murtha
Life of this patent
Estimating the term…
Abstract
Compounds having the formula ##STR1## are prepared from a corresponding o-nitrophenol by blocking the hydroxyl groups via acetal formation, followed by reductive coupling and acid hydrolysis.
Claims18
A process for the preparation of an o,o'-dihydroxyazobenzene having the following formula ##STR6## wherein the R's are individually selected from the group consisting of hydrogen, alkyl, aryl, cycloalkyl, alkaryl, aralkyl, alkoxy, aryloxy, tert-amino, and alkylthio, said R's containing up to about 12 carbon atoms, which comprises
- 1. forming an acetal of an o-nitrophenol of the formula:
- ##STR7## wherein the R's are as earlier stated,
A process for the preparation of 2,2'-dihydroxy-5,5'-bis-(1,1,3,3-tetramethylbutyl)azobenzene comprising
- 1. forming an acetal of 2-nitro-4-(1,1,3,3-tetramethylbutyl)phenol,
- 2. reacting said acetal with a reducing agent selected from the group consisting of lithium aluminum hydride, sodium aluminum diethyl dihydride, and sodium borohydride under conditions sufficient to produce the corresponding diacetal azobenzene;
- and
- 3. employing acid hydrolysis upon said diacetal azobenzene to regenerate the hydroxyl groups and yield the corresponding dihydroxy azobenzene.
A process for the preparation of an o,o'-dihydroxyazobenzene having the formula ##STR8## wherein the R's are individually selected from the group consisting of hydrogen and hydrocarbyl, said R's containing up to about 12 carbon atoms, which comprises
- 1. forming an acetal of an o-nitrophenol of the formula:
- ##STR9##
- wherein the R's are as earlier stated, 2. reacting said acetal with a reducing agent under such conditions that said acetal is converted to the corresponding diacetal azobenzene, and
- 3. then employing acid hydrolysis upon said diacetal azobenzene to regenerate the hydroxyl groups and yield the corresponding o,o'-dihydroxyazobenzene.
A process for the preparation of an o,o'-dihydroxyazobenzene having the following formula ##STR10## wherein the R's are individually selected from the group consisting of hydrogen, alkyl, aryl, cycloalkyl, alkaryl, aralkyl, alkoxy, aryloxy, tert-amino, and alkylthio, said R's containing up to about 12 carbon atoms, which consists essentially of
- 1. forming an acetal of an o-nitrophenol of the formula:
- ##STR11##
- wherein the R's are as earlier stated, 2. reacting said acetal with a reducing agent under such conditions that said acetal is converted to the corresponding diacetal azobenzene, and
- 3. then employing acid hydrolysis upon said diacetal azobenzene to regenerate the hydroxyl groups and yield the corresponding o,o'-dihydroxyazobenzene.
Dependencies are inferred from the claim text.