Sankyo Company, Limited

Susumu Higashida

Tomoyuki Kurumada

Katsuaki Matsui

Takao Yoshioka

Keisuke Murayama

Eiko Mori

Toshimasa Toda

Hideo Horiuchi

Syoji Morimura

Noriyuki Ohta

Hisayou Ohsawa

Hisayou Osawa

Noriyuki Ohata

Hiroshi Handa

Yuichiro Yabe

Tomoaki Komai

Hisayu Ohsawa

Takashi Nishigaki

Mitsuya Sakurai

Keisuku Murayama

Syoji Moriyama

Compounds of formula (I): ##STR1## wherein: R.sup.1 is hydrogen, alkyl, aralkyl, --COR.sup.a, --COR.sup.b, --CSR.sup.a, --CSR.sup.b, --SO.sub.2 R.sup.b, --CONHR.sup.b, --CSNHR.sup.b, --CONR.sup.b R.sup.b or --CSNR.sup.b R.sup.b ; R.sup.2 is hydrogen or alkyl; R.sup.3 is hydrogen, alkylidene, substituted alkyl, or R.sup.b ; R.sup.4 is optionally substituted alkyl, cycloalkyl, or aryl; R.sup.5 is R.sup.b O--, R.sup.b R.sup.b N--, R.sup.b HN--, aralkyloxycarbonyloxy or aralkyloxycarbonylamino, or R.sup.5 is --(CH.sub.2).sub.p --D--(CH.sub.2).sub.r --, where D is a single bond, carbonyl, oxygen, sulfur, --NH--, --(CH.sub.2 .dbd.CH.sub.2)-- or --NHCO--; and p and r are each 0 or an integer from 1 to 5; A is --(CH.sub.2).sub.m --B--(CH.sub.2).sub.n -- where B is a single bond, carbonyl, oxygen, sulfur, --NH--, --(CH.sub.2 .dbd.CH.sub.2)-- or --NHCO--; and m and n are each 0 or an integer from 1 to 5; R.sup.a is alkoxy, aralkyloxy, aryloxy or alkoxycarbonyl; R.sup.b is optionally substituted alkyl, cycloalkyl, heterocyclic, aryl or arylalkenyl; and pharmaceutically acceptable salts and esters thereof and pro-drugs therefor, have the ability to inhibit the activity of HIV protease and may thus be used for the treatment and prophylaxis of AIDS.

Inhibitors of HIV protease

Piperidine derivatives having the formula ##STR1## wherein R' represents an alkyl, an acyl, an alkoxycarbonyl, an amino or nitroso group;

Piperidine derivatives

A novel piperidine derivative having a stabilizing effect on a synthetic polymeric material and a composition comprising said piperidine derivative and a synthetic polymeric material.

A synthetic polymer composition stabilized against photo- and thermal-deterioration comprising a stabilizing amount of a compound having the formula ##STR1## wherein R' represents an alkyl, an acyl, an alkoxycarbonyl, an amino or nitroso group;

Polymer compositions containing piperidine derivatives as stabilizers

Novel piperidine derivatives of formula: ##STR1## (wherein 2 or 3 of R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 represent alkyl groups having from 1 to 4 carbon atoms and the remainder of R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are hydrogen atoms, and R.sub.6 represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a substituted alkyl group, an aliphatic acyl group, an alkoxycarbonyl group or an aralkoxycarbonyl group) are useful as stabilizers for synthetic polymers.

Novel piperidine derivatives for the stabilization of synthetic polymers

Piperidine-spiro-hydrantoin derivatives having the formula ##STR1## wherein X represents oxygen atom or sulfur atom; n is an integer of 1 to 4 inclusive; and

Piperidine-spiro-hydantoin derivatives

Piperidine-spiro-hydantoin derivatives having the formula ##SPC1## Wherein X represents oxygen atom or sulfur atom; n is an integer of 1 to 4 inclusive, and R represents various aliphatic or aromatic groups depending on the value of n. These compounds (I) are useful as stabilizers against photo and thermal deterioration of various synthetic polymers and can be prepared, for example, by reacting the corresponding 3-unsubstituted piperidine-spiro-hydantoin compound with the halide R-(X.sub.1).sub.n in which R and n are as defined herein and X.sub.1 is a halogen atom.

Piperidine-spiro-hydantoin derivatives and their use as stabilizers

Piperidine derivatives having the formula ##SPC1## Wherein

Piperidine derivatives and their use as stabilizers

4-Piperidone derivatives having the formulae ##SPC1## Wherein R represents a phenyl or naphthyl group which may be substituted with nitro, lower alkyl, halogen, hydroxyl, lower alkyl hydroxy, hydroxy lower alkyl or formyl or a 5- or 6-membered heterocyclic group having as a hetero atom at least one of oxygen atom, sulfur atom and nitrogen atom and R.sub.1 represents hydrogen atom or an alkyl group of 1 to 4 carbon atoms. They are useful as stabilizers for various synthetic polymers against their photo- and thermal-deteriorations and the 4-piperidone derivatives (II) are prepared from the corresponding 2,2,6,6-tetramethyl-4-oxopiperidine derivatives by reaction with an aldehyde and the 4-piperidone derivatives (I) are prepared from the 4-piperidone derivatives (II) through dehydration.

Growing community of inventors

Tokyo, Japan

Susumu Higashida