Method for preparing 2-phenylbenzotriazoles

Details Method for preparing 2-phenylbenzotriazoles Method for preparing 2-phenylbenzotriazoles

1988-08-12

1990-07-24

Daus, Donald G.

Organic compounds -- part of the class 532-570 series

Organic compounds

Heterocyclic carbon compounds containing a hetero ring...

548259, C07D24920

Patent

active

049436376

ABSTRACT:
This invention relates to a method for preparing a 2-phenylbenzotriazole of formula I, ##STR1## (wherein R.sub.1 represents hydrogen or chlorine atom, a lower alkyl group having a carbon number of 1 to 4, a lower alkoxy group having a carbon number of 1 to 4, carboxyl group, or sulfonic acid group; R.sub.2 represents hydrogen or chlorine atom, a lower alkyl group having a carbon number of 1 to 4, or a lower alkoxy group having a carbon number of 1 to 4; R.sub.3 represents hydrogen or chlorine atom, an alkyl group having a carbon number of 1 to 12, a lower alkoxyl group having a carbon number of 1 to 4, phenyl group, a phenyl group substituted with an alkyl group having a carbon number of 1 to 8, phenoxy group, or a phenylalkyl group, the alkyl part of which has a carbon number of 1 to 4; R.sub.4 represents hydrogen or chlorine atom, hydroxyl group, or a lower alkoxy group having a carbon number of 1 to 4; and R.sub.5 represents hydrogen atom, an alkyl group having a carbon number of 1 to 12, or a phenylalkyl group, the alkyl part of which has a carbon number of 1 to 4), which comprises reducing an o-nitroazobenzene of formula III, ##STR2## (wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are as defined above) with at least one selected from the group consisting of primary and secondary alcohol reducing agents in the presence of an aromatic ketone catalyst and base.
This invention further relates to a method for preparing a 2-phenylbenzotriazole of formula I as defined above, which comprises reducing 1 mole 2-phenylbenzotriazole-N-oxide of formula II, ##STR3## (wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are as defined above) with 0.4 to 0.7 mole primary alcohol and/or 0.8 to 1.4 mole secondary alcohol in the presence of an aromatic ketone catalyst and base.
This invention still further relates to a method for preparing a 2-phenylbenzotriazole-N-oxide of formula II as defined above, which comprises reducing 1 mole o-nitroazobenzene of formula III as defined above with 0.4 to 0.7 mole primary alcohol and/or 0.8 to 1.4 mole secondary alcohol in the presence of an aromatic ketone catalyst and base.

REFERENCES:
patent: 4642350 (1987-02-01), Davatz
patent: 4780541 (1988-10-01), Seino
patent: 4835284 (1989-05-01), Seino
Fieser and Fieser, Organic Chemistry, 3rd Ed., (1956: Reinhold Publishing Co., N.Y.), p. 362.

Affiliated with

Also associated with

Rating

Method for preparing 2-phenylbenzotriazoles does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method for preparing 2-phenylbenzotriazoles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for preparing 2-phenylbenzotriazoles will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1268456