JP3716472B2 - Triazolopyrimidine derivatives - Google Patents

Description

【０００８】
（式中、Ａは炭素数１〜４個のアルキレン基を示し、Ｒ¹は炭素数１〜２０個のアルキル基を示し、Ｒ²は水素原子又は炭素数１〜４個のアルキル基を示し、Ｒ³はメチル基又はモルホリノ基を示す。）で表わされるトリアゾロピリミジン誘導体又はそれらの塩である。
【０００９】
本発明において、アルキル基とは直鎖状又は分枝鎖状のアルキル基であり、炭素数１〜４個のアルキル基とは、例えばメチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、第３ブチル基であり、炭素数１〜２０個のアルキル基とは、前記の他、例えばｎ−オクチル基、イソオクチル基、デシル基、テトラデシル基などである。アルキレン基とは直鎖状又は分枝鎖状のアルキレン基であり、それらは例えばメチレン基、エチレン基、プロピレン基、トリメチレン基などである。また、本発明の塩とは製薬学的に許容される塩を意味し、それらは例えば塩酸塩、臭化水素酸塩、メタンスルホン酸塩などである。
【００１０】
【発明の実施の形態】
式（Ｉ）の化合物は、例えば次の方法で製造することができる。即ち、式
【００１１】
【化３】

【００１２】
（式中、Ｒ²及びＲ³は前記と同意義である。）で示される化合物を式Ｘ−Ａ−ＣＯＸ' （III）（式中、Ｘ及びＸ'はハロゲン原子を示し、Ａは炭素数１〜４個のアルキレン基を示す。）で示される化合物と、塩基もしくは溶媒の存在下又は両者の存在下もしくは非存在下に反応させることによって下記式（IV）
【００１３】
【化４】

【００１４】
で示される化合物に導いた後、式Ｒ¹ＳＨ （Ｖ）（式中、Ｒ¹は前記と同意義である。）で示される化合物と塩基もしくは溶媒の存在下又は両者の存在下もしくは非存在下に反応させることによって製造することができる。
【００１５】
また、式（Ｉ）の化合物は、式（II）で示される化合物と式Ｒ¹Ｓ−Ａ−ＣＯ₂Ｈ （VI）（式中、Ｒ¹及びＡは前記と同意義である。）で示される化合物を塩基もしくは溶媒の存在下又は両者の存在下もしくは非存在下に反応させることによって製造することもできる。
【００１６】
上記の反応に用いる塩基としては、例えば炭酸カリウム、炭酸ナトリウム、水酸化ナトリウム、水酸化カリウム等のアルカリ塩類、トリエチルアミン、ジイソプロピルエチルアミン、ピリジン等のアミン類、水素化ナトリウム、水素化カリウム、ナトリウムアミド等、ナトリウムメトキシド、ナトリウムエトキシド、第３ブチルカリウム等のアルコキシド類等を挙げることができ、反応溶媒としては、例えば水、酢酸、メタノール、エタノールイソプロピルアルコール、第３ブチルアルコール等のアルコール類、ジオキサン、テトラヒドロフラン等のエーテル類、ジメチルホルムアミド、ジメチルスルホキシド、塩化メチレン、クロロホルム、アセトン、トルエン、ベンゼン等の反応に不活性な溶媒を用いることができる。また、ハロゲン原子とは、フッ素原子、塩素原子、臭素原子又は沃素原子である。
【００１７】
【発明の効果】
本発明の化合物は強力なＡＣＡＴ阻害作用を有し、抗動脈硬化剤及び脂質低下剤として有用である。
【００１８】
【実施例】
以下、実施例及び試験例を挙げてさらに本発明を詳細に説明する。
実施例１
（１）５−メチル−７−ヒドロキシ［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（５０.８８ｇ）とオキシ塩化リン（２４２ｇ）の混合物を３０分間加熱還流した後、反応混合物を蒸発乾固した。残渣に水及び塩化メチレンを加え、濃アンモニア水でｐＨを１１にした後不溶物を濾過した。塩化メチレン層を飽和食塩水で洗浄後、無水硫酸マグネシウム乾燥、塩化メチレンを減圧留去して微黄色プリズム晶の５−メチル−７−クロロ［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（３３.１ｇ）を得た。
融点 １４７.５〜１４９.５℃。
【００１９】
（２）前記（１）で得た化合物（１６.８ｇ）、２８％アンモニア水（３０ｍｌ）及び２−プロパノール（５００ｍｌ）の混合物を室温で２.５時間撹拌した。反応混合物を減圧下に濃縮した際に析出した結晶を濾取して５−メチル−７−アミノ［１.２.４］トリアゾロ［１,５−ａ］ピリミジン・塩酸塩（１８.６５ｇ）を得た。
融点 ２２７〜２３０℃。
【００２０】
（３）前記（２）で得た化合物（７.４２ｇ）、トリエチルアミン（１６.７３ｍｌ）及びクロロホルム（３００ｍｌ）の混合物に氷冷下クロロアセチルクロリド（３.５ｍｌ）を滴下し、室温下で３時間撹拌した。反応混合物を減圧留去した後得た残渣をシリカゲルカラムクロマトグラフィー（展開溶媒；メタノール：クロロホルム＝１：９）に付して５−メチル−７−（２−クロロアセチルアミノ）［１.２.４］トリアゾロ［１,５−ａ］ピリミジンを得た。
融点 １６５〜１７５℃。
【００２１】
（４）前記（３）で得た化合物（２.４ｇ）、テトラデシルメルカプタン（２.９ｇ）、炭酸カリウム（４.４ｇ）及びアセトン（５０ｍｌ）の混合物をアルゴン雰囲気下に２時間加熱還流した。反応混合物を水に注いだ後、塩化メチレンで抽出した。塩化メチレン層を飽和食塩水で洗浄後、無水硫酸マグネシウムで乾燥、塩化メチレンを減圧留去した。残渣をシリカゲルカラムクロマトグラフィー（展開溶媒；酢酸エチル：ヘキサン＝５０：５０）に付して５−メチル−７−（２−テトラデシルチオアセチルアミノ）［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（化合物１）を得た（２.７８ｇ）。
融点 ８５〜８６℃。
【００２２】
実施例２
（１）実施例１（２）で得た化合物（７.４２ｇ）、２−ブロモ−２−メチルプロピオニルブロマイド（５.４ｍｌ）及びクロロホルム（３５０ｍｌ）の混合物に氷冷下トリエチルアミン（６.１ｍｌ）を滴下した。反応混合物を室温で１時間撹拌した後減圧蒸留し、残渣を水で洗浄して５−メチル−７−（２−ブロモ−２−メチルプロピオニルアミノ）［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（５.６５ｇ）を得た。
融点 １１５〜１１６℃。
【００２３】
（２）２−プロパノール（４０ｍｌ）に懸濁させた６０％水素化ナトリウム（０.３ｇ）にテトラデシルメルカプタン（２.０ｇ）を加え澄明な溶液を得た。この溶液を前記（１）で得た化合物（２.０ｇ）と２−プロパノール（４０ｍｌ）の混合物中に室温下に滴下した。反応混合物を減圧蒸留した後、残渣に３％塩酸と塩化メチレンを加え撹拌した。塩化メチレン層を飽和食塩水で洗浄後、無水硫酸マグネシウムで乾燥、塩化メチレンを減圧留去した。残渣をシリカゲルカラムクロマトグラフィー（展開溶媒；メタノール：塩化メチレン＝５：９５）に付して５−メチル−７−（２−テトラデシルチオ−２−メチルプロピオニルアミノ）［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（化合物２）を得た。
融点 ５８〜６０℃。
【００２４】
実施例３
（１）２−メチルアセト酢酸エチル（２５.８ｇ）、３−アミノ−１,２,４トリアゾール（１４.３ｇ）と酢酸（２００ｍｌ）の混合物を加熱還流下に７時間撹拌した。反応混合物を放冷後に析出した結晶を濾取して７−ヒドロキシ−５,６−ジメチル［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（１５.９ｇ）を得た。
融点 ３００℃以上
¹Ｈ−ＮＭＲ（ＤＭＳＯ−ｄ₆）δ：１.９７（ｓ,３Ｈ），２.３３（ｓ,３Ｈ），８.１６（ｓ,１Ｈ），１３.００（ｂｒ,１Ｈ）。
【００２５】
（２）前記（１）で得た化合物（２３ｇ）とオキシ塩化リン（４５ｍｌ）の混合物を２時間加熱還流下に撹拌した後、反応混合物を蒸発乾固した。残渣に水及び塩化メチレンを加え、濃アンモニア水でｐＨを１１にした後不溶物を濾過した。塩化メチレン層を飽和食塩水で洗浄後、無水硫酸マグネシウム乾燥、塩化メチレンを減圧留去し、残渣をシリカゲルカラムクロマトグラフィー（展開溶媒；酢酸エチル：塩化メチレン＝１：１）に付して５,６−ジメチル−７−クロロ［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（２１.３ｇ）を得た。
¹Ｈ−ＮＭＲ（ＤＭＳＯ−ｄ₆）δ：２.４１（ｓ,３Ｈ），２.６５（ｓ,３Ｈ），８.６０（ｓ,１Ｈ）。
【００２６】
（３）前記（２）で得た化合物（１５ｇ）、２５％アンモニア水（１６８ｍｌ）及び２−プロパノール（８４０ｍｌ）の混合物を室温で６時間撹拌した。反応混合物を減圧下に濃縮した際に析出した結晶を濾取して５,６−ジメチル−７−アミノ［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（１２.２ｇ）を得た。
融点 １５８〜１６０℃。
【００２７】
（４）２−（テトラデシルチオ）酢酸（０.４３３ｇ）と塩化チオニル（３ｍｌ）の混合物を室温下１６時間撹拌した後、減圧蒸留した。残渣にクロロホルム５０ｍｌ）、前記（３）で得た化合物（０.２４４ｇ）、ピリジン（０.１５ｍｌ）を順次加え、室温下で１６時間撹拌した。反応混合物を水に注いだ後、酢酸エチルで抽出した。酢酸エチル層を飽和食塩水で洗浄後、無水硫酸マグネシウム乾燥、酢酸エチルを減圧留去し、残渣をシリカゲルカラムクロマトグラフィー（展開溶媒；酢酸エチル：塩化メチレン＝１：１）に付して５,６−ジメチル−７−（２−テトラデシルチオアセチルアミノ）［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（化合物３）を得た。
融点 ７７〜７９℃。
【００２８】
実施例４
（１）実施例３（３）で得た化合物（１.６３ｇ）とピリジン（２０ｍｌ）の混合物に氷冷下２−ブロモ−２−メチルプロピオニルブロマイド（１.２４ｍｌ）を滴下した。反応混合物を氷冷下で２時間撹拌した後減圧蒸留し、残渣を水で洗浄して５,６−ジメチル７−（２−ブロモ−２−メチルプロピオニルアミノ）［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（２.６７ｇ）を得た。
融点 １５８〜１６０℃。
【００２９】
（２）２−プロパノール（５０ｍｌ）に懸濁させた６０％水素化ナトリウム（０.３８４ｇ）にテトラデシルメルカプタン（２.４ｍｌ）を加え澄明な溶液を得た。この溶液を（１）で得た化合物（２.５ｇ）とテトラヒドロフラン（４０ｍｌ）の混合物中に室温下に滴下した。反応混合物を減圧蒸留した後、残渣に３％塩酸と塩化メチレンを加え撹拌した。塩化メチレン層を飽和食塩水で洗浄後、無水硫酸マグネシウムで乾燥、塩化メチレンを減圧留去し、残渣をシリカゲルカラムクロマトグラフィー（展開溶媒；メタノール：クロロホルム＝３：９７）に付して５,６−ジメチル−７−（２−テトラデシルチオ−２−メチルプロピオニルアミノ）［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（化合物４）を得た。
融点 ８６〜８８℃。
【００３０】
実施例５
（１）２−メチルマロン酸ジエチル（２６.３ｇ）、３−アミノ−１,２,４トリアゾール（１２.７ｇ）、ナトリウムエトキシド（１０.８ｇ）及びエタノール（３３０ｍｌ）の混合物を加熱還流下に７時間撹拌した。反応混合物を放冷後に析出した結晶を濾取し水に加えて澄明な溶液を得た。この水溶液に濃塩酸を加えｐＨを１とし、析出した結晶を濾取、水洗して５,７−ジヒドロキシ−６−メチル［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（７.８７ｇ）を得た。
融点 ３００℃以上
¹Ｈ−ＮＭＲ（ＤＭＳＯ−ｄ₆）δ：１.８５（ｓ,３Ｈ），８.５９（ｓ,１Ｈ），１２.２５（ｂｒ,１Ｈ）。
【００３１】
（２）前記（１）で得た化合物（７.６８ｇ）とオキシ塩化リン（５０ｍｌ）の混合物を２時間加熱還流下に撹拌した後、反応混合物を蒸発乾固した。残渣に水及び塩化メチレンを加え、次いで飽和炭酸水素ナトリウム液を加え液性を弱アルカリ性にした後、不溶物を濾過した。塩化メチレン層を飽和食塩水で洗浄後、無水硫酸マグネシウム乾燥、塩化メチレンを減圧留去し、残渣をシリカゲルカラムクロマトグラフィー（展開溶媒；酢酸エチル：塩化メチレン＝１：４）に付して５,７−ジクロロ−６−メチル［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（６.８６ｇ）を得た。
融点 １４７〜１４９℃。
【００３２】
（３）前記（２）で得た化合物（１ｇ）、２５％アンモニア水（１９.７ｍｌ）及び２−プロパノール（１０ｍｌ）の混合物を室温で１６時間撹拌した。反応混合物を減圧下に濃縮した際に析出した結晶を濾取して７−アミノ−５−クロロ−６−メチル［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（０.８０５ｇ）を得た。
融点 ３００℃以上
¹Ｈ−ＮＭＲ（ＤＭＳＯ−ｄ₆）δ：２.２３（ｓ,３Ｈ），８.３０（ｂｒ,２Ｈ），８.４４（ｓ,１Ｈ）。
【００３３】
（４）前記（３）で得た化合物（０.１８４ｇ）とモルホリン（５ｍｌ）の混合物を１００℃で３時間撹拌した。反応混合物を放冷後析出した結晶を濾取、クロロホルム洗浄して７−アミノ−５−モルホリノ−６−メチル［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（０.１６５ｇ）を得た。
融点 ３００℃以上
¹Ｈ−ＮＭＲ（ＤＭＳＯ−ｄ₆）δ：２.０６（ｓ,３Ｈ），３.１７（ｍ,４Ｈ），３.７３（ｍ,４Ｈ），７.４７（ｂｒ,２Ｈ），８.２２（ｓ,１Ｈ）。
【００３４】
（５）２−（テトラデシルチオ）酢酸（０.１２４ｇ）と塩化チオニル（２ｍｌ）の混合物を室温下１６時間撹拌した後減圧蒸留した。残渣にクロロホルム５０ｍｌ）、前記（４）で得た化合物（０.２４４ｇ）、ジイソプロピルエチルアミン（０.１ｍｌ）を順次加え、室温下で２時間撹拌した。反応混合物を水に注いだ後、酢酸エチルで抽出した。酢酸エチル層を飽和食塩水で洗浄後、無水硫酸マグネシウム乾燥、酢酸エチルを減圧留去し、残渣をシリカゲルカラムクロマトグラフィー（展開溶媒；酢酸エチル：塩化メチレン＝１：１）に付して６−メチル−５−モルホリノ−７−（２−テトラデシルチオアセチルアミノ）［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（化合物５）を得た。
融点 ６０〜６６℃。
【００３５】
実施例６
（１）実施例５（４）で得た化合物（１.８ｇ）とピリジン（３０ｍｌ）の混合物に氷冷下２−ブロモ−２−メチルプロピオニルブロマイド（０.９５ｍｌ）を滴下した。反応混合物を氷冷下で２時間撹拌した後減圧蒸留し、残渣を水で洗浄して６−メチル−５−モルホリノ−７−（２−ブロモ−２−メチルプロピオニルアミノ）［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（１.７７ｇ）を得た。
融点 １５２.５〜１５４℃。
【００３６】
（２）２−プロパノール（３０ｍｌ）に懸濁させた６０％水素化ナトリウム（０.１９２ｇ）にテトラデシルメルカプタン（１.０ｇ）を加え澄明な溶液を得た。この溶液を前記（１）で得た化合物（１.７ｇ）と２−プロパノール（１０ｍｌ）の混合物中に室温下に滴下した。反応混合物を減圧蒸留した後、残渣に３％塩酸と塩化メチレンを加え撹拌した。塩化メチレン層を飽和食塩水で洗浄後、無水硫酸マグネシウムで乾燥、塩化メチレンを減圧留去し、残渣をシリカゲルカラムクロマトグラフィー（展開溶媒；メタノール：クロロホルム＝３：９７）に付して６−メチル−５−モルホリノ−７−（２−テトラデシルチオ−２−メチルプロピオニルアミノ）［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（化合物６）を得た。
融点 ４９〜５２℃。
【００３７】
実施例７
（１）２−イソプロピルマロン酸ジエチル（７５.９ｇ）、３−アミノ−１,２,４トリアゾール（２９.６７ｇ）、ナトリウムエトキシド（３０.３ｇ）とエタノール（７６０ｍｌ）の混合物を加熱還流下に６時間撹拌した。反応混合物を放冷後に析出した結晶を濾取し、水に加えて澄明な溶液を得た。この水溶液に濃塩酸を加えｐＨを１とし、析出した結晶を濾取、水洗して５,７−ジヒドロキシ−６−イソプロピル［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（５.９４ｇ）を得た。
融点 ２８３〜２８５℃。
【００３８】
（２）前記（１）で得た化合物（６.０ｇ）とオキシ塩化リン（４０ｍｌ）の混合物を４時間加熱還流下に撹拌した後、反応混合物を蒸発乾固した。残渣に水及び塩化メチレンを加え、次いで飽和炭酸水素ナトリウム液を加え液性を弱アルカリ性にした後、不溶物を濾過した。塩化メチレン層を飽和食塩水で洗浄後、無水硫酸マグネシウム乾燥、塩化メチレンを減圧留去し、残渣をシリカゲルカラムクロマトグラフィー（展開溶媒；酢酸エチル：塩化メチレン＝１：４）に付して５,７−ジクロロ−６−イソプロピル［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（４.０７ｇ）を得た。
融点 １４０.５〜１４２℃。
【００３９】
（３）前記（２）で得た化合物（３.９ｇ）、２５％アンモニア水（４.７ｍｌ）及び２−プロパノール（１５０ｍｌ）の混合物を室温で１６時間撹拌した。反応混合物を減圧下に濃縮した際に析出した結晶を濾取して７−アミノ−５−クロロ−６−イソプロピル［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（３.２５ｇ）を得た。
融点 ３００℃以上
¹Ｈ−ＮＭＲ（ＤＭＳＯ−ｄ₆）δ：１.３４（ｄ,Ｊ＝６Ｈｚ,６Ｈ），３.５０（ｍ,１Ｈ），８.２０（ｂｒ,２Ｈ），８.４６（ｓ,１Ｈ）。
【００４０】
（４）前記（３）で得た化合物（３.１ｇ）とモルホリン（５０ｍｌ）の混合物を１２０℃で３時間撹拌した。反応混合物を放冷後析出した結晶を濾取、クロロホルム洗浄して７−アミノ−５−モルホリノ−６−イソプロピル［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（３.３４ｇ）を得た。
融点 ３００℃以上
¹Ｈ−ＮＭＲ（ＤＭＳＯ−ｄ₆）δ：１.３３（ｄ,Ｊ＝６Ｈｚ,６Ｈ），３.０８（ｍ,４Ｈ），３.３６（ｍ,１Ｈ），３.７５（ｍ,４Ｈ），７.２８（ｓ,２Ｈ），８.３０（ｓ,１Ｈ）。
【００４１】
（５）２−（テトラデシルチオ）酢酸（１.４４ｇ）と塩化チオニル（１０ｍｌ）の混合物を室温下１６時間撹拌した後減圧蒸留した。残渣にクロロホルム５０ｍｌ）、前記（４）で得た化合物（１.３１ｇ）、ジイソプロピルエチルアミン（１.０ｍｌ）を順次加え、室温下で２時間撹拌した。反応混合物を水に注いだ後、酢酸エチルで抽出した。酢酸エチル層を飽和食塩水で洗浄後、無水硫酸マグネシウム乾燥、酢酸エチルを減圧留去し、残渣をシリカゲルカラムクロマトグラフィー（展開溶媒；酢酸エチル：塩化メチレン＝３：２）に付して６−イソプロピル−５−モルホリノ−７−（２−テトラデシルチオアセチルアミノ）［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（化合物７）を得た。
融点 １２５.５〜１２７.５℃。
【００４２】
試験例［ＡＣＡＴ阻害作用］
試験はJ. Lipid Res. 22, 271(1981)に記載の方法に準じて行った。
ウサギ小腸ミクロソーム分画は常法に従って調製し、得られたミクロソーム分画を０.１規定ショ糖、０.０３規定エチレンジアミン四酢酸（ＥＤＴＡ）及び０.０５規定塩化カリウムを含む０.０４規定燐酸カリウム緩衝液（ｐＨ７.４）に懸濁した。
被験薬は実施例６で得られた化合物及び比較薬としての５−メチル−７−ジエチルアミノ［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（特開昭５６−１０８７７２号）を用い、それぞれジメチルスルホキシドに溶解して調製した。 １％牛血清アルブミンを含む０.０５規定燐酸緩衝液（ｐＨ７.４）に上記ウサギ小腸ミクロソーム分画懸濁液（タンパク質量として２５０μｇ）、［１−¹⁴Ｃ］オレイルＣｏＡを加え、さらにこれに各種濃度の被験薬を加え全量を５００μｌとした。この混合物を３７℃で６分間インキュベートした後、クロロホルムとメタノールの混合液（混合比＝２：１）を加え反応を停止した。撹拌後、クロロホルム層を採取し、これを濃縮乾固した。これにコレステロールオレエートのクロロホルム溶液（濃度１０ｍｇ／ｍｌ）３０μｌを加え、シリカゲル薄層板（メルク社キーゼルゲル６０Ｆ₂₅₄Ａｒｔ５７１５）にスポットしてヘキサンと酢酸エチルの混合液（混合比＝１００：３）で展開した。コレステロールオレエートに相当する部分をかきとり、放射活性を液体シンチレーションカウンター（アロカ社製ＬＳＣ−３０００）で測定し、下記の式を用いてＡＣＡＴ活性の抑制率を求めＩＣ₅₀値を算出した。
【００４３】
【数１】

【００４４】
その結果、実施例６で得られた化合物のＩＣ₅₀値は６.０５×１０^-6Ｍであった。
【００４５】
対照薬として用いた５−メチル−７−ジエチルアミノ［１.２.４］トリアゾロ［１,５−ａ］ピリミジン（特開昭５６−１０８７７２号に記載されている化合物）は、１×１０^-4Ｍの濃度においてもＡＣＡＴ阻害活性を示さなかった。[0001]
[Industrial application fields]
The present invention relates to a triazolopyrimidine derivative, and more particularly to a triazolopyrimidine derivative having an inhibitory action on acyl-CoA enzyme cholesterol transferase (hereinafter referred to as ACAT).
[0002]
[Prior art]
ACAT is an enzyme that catalyzes the synthesis of fatty acid acyl-CoA and cholesterol to cholesterol ester, and it is known that a large part of the esterification of cholesterol in vivo is performed by the action of ACAT (AASpector et al. Prog. Lipid Res. 18, 31-53 (1979)). In experimentally prepared atherosclerotic lesions, an increase in ACAT activity is observed, and it has been pointed out that cholesterol ester accumulation in atherosclerotic lesions is associated with ACAT activity (RWSt. Clair et al. al Circ. Res. 27,213-225 (1970). RWSt. Clair et al Prog. Cardiovasc. Dis. 26, 109-132 (1983). PM Kinnuen et al Biochemistry 27,7344-7350 (1988)).
[0003]
On the other hand, in the absorption of diet-derived cholesterol, it is known that free cholesterol present in the intestinal tract is esterified in the mucous membrane of the small intestine and then secreted into the lymphatic vessels as kilomicrons. It is known that the esterification of cholesterol by ACAT present in the small intestinal mucosa is greatly involved (KE Suckling et al J. Lipid Res. 26, 647-671 (1985), JG Heider et al J. Lipid Res. 24, 176-183 (1983)). In this way, the ACAT inhibitor acts on the arteriosclerotic lesion and suppresses the accumulation of cholesterol ester, thereby suppressing the production and progression of atherosclerosis and acting on the liver to lower blood cholesterol, and the small intestine. It is conceivable to suppress cholesterol absorption by acting on the mucous membrane.
[0004]
Compounds having the same [1.2.4] triazolo [1,5-a] pyrimidine skeleton as the compounds of the present invention are disclosed in JP-A-56-108772 and JP-A-4-99775. However, no ACAT inhibitory activity has been reported for these compounds.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a compound having a stronger ACAT inhibitory action and useful as an anti-arteriosclerotic agent and a lipid lowering agent.
[0006]
[Means for Solving the Problems]
The present invention has the formula
[Chemical formula 2]

[0008]
(In the formula, A represents an alkylene group having 1 to 4 carbon atoms, R ¹ represents an alkyl group having 1 to 20 carbon atoms, and R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. , R ³ represents a methyl group or a morpholino group.) Or a salt thereof.
[0009]
In the present invention, the alkyl group is a linear or branched alkyl group, and the alkyl group having 1 to 4 carbon atoms is, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, In addition to the above, an alkyl group having 1 to 20 carbon atoms is an n-octyl group, an isooctyl group, a decyl group, a tetradecyl group, and the like. The alkylene group is a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, a propylene group, and a trimethylene group. The salt of the present invention means a pharmaceutically acceptable salt, and examples thereof include hydrochloride, hydrobromide, methanesulfonate and the like.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The compound of the formula (I) can be produced, for example, by the following method. That is, the formula
[Chemical 3]

[0012]
(Wherein R ² and R ³ have the same meanings as described above) are represented by the formula XA-COX ′ (III) (wherein X and X ′ represent a halogen atom, and A represents carbon. And a compound represented by formula (IV) below by reacting in the presence of a base or a solvent or in the presence or absence of both.
[0013]
[Formula 4]

[0014]
And then, in the presence of a compound represented by the formula R ¹ SH (V) (wherein R ¹ is as defined above) and a base or a solvent, or both, or the absence thereof. It can manufacture by making it react below.
[0015]
Further, the compound of the formula (I) is a compound represented by the formula (II) and a formula R ¹ S—A—CO ₂ H (VI) (wherein R ¹ and A are as defined above). It can also be prepared by reacting the indicated compound in the presence of a base or solvent or in the presence or absence of both.
[0016]
Examples of the base used in the above reaction include alkali salts such as potassium carbonate, sodium carbonate, sodium hydroxide and potassium hydroxide, amines such as triethylamine, diisopropylethylamine and pyridine, sodium hydride, potassium hydride, sodium amide and the like. And alkoxides such as sodium methoxide, sodium ethoxide, and tertiary butyl potassium. Examples of the reaction solvent include water, acetic acid, methanol, ethanol isopropyl alcohol, tertiary butyl alcohol and other alcohols, dioxane, and the like. Inert solvents such as tetrahydrofuran, ethers such as tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, methylene chloride, chloroform, acetone, toluene, benzene and the like can be used. The halogen atom is a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.
[0017]
【The invention's effect】
The compound of the present invention has a potent ACAT inhibitory action and is useful as an anti-atherosclerotic agent and a lipid lowering agent.
[0018]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples and test examples.
Example 1
(1) A mixture of 5-methyl-7-hydroxy [1.2.4] triazolo [1,5-a] pyrimidine (50.88 g) and phosphorus oxychloride (242 g) was heated to reflux for 30 minutes, and then the reaction mixture Was evaporated to dryness. Water and methylene chloride were added to the residue, the pH was adjusted to 11 with concentrated aqueous ammonia, and the insoluble material was filtered off. The methylene chloride layer was washed with saturated brine, dried over anhydrous magnesium sulfate, and methylene chloride was distilled off under reduced pressure to give 5-methyl-7-chloro [1.2.4] triazolo [1,5-a as a slightly yellow prism crystal. Pyrimidine (33.1 g) was obtained.
Melting point: 147.5-149.5 ° C.
[0019]
(2) A mixture of the compound (16.8 g) obtained in (1), 28% aqueous ammonia (30 ml) and 2-propanol (500 ml) was stirred at room temperature for 2.5 hours. Crystals precipitated when the reaction mixture was concentrated under reduced pressure were collected by filtration to give 5-methyl-7-amino [1.2.4] triazolo [1,5-a] pyrimidine hydrochloride (18.65 g). Obtained.
Melting point 227-230 [deg.] C.
[0020]
(3) To a mixture of the compound (7.42 g) obtained in (2), triethylamine (16.73 ml) and chloroform (300 ml), chloroacetyl chloride (3.5 ml) was added dropwise under ice-cooling, and 3 at room temperature. Stir for hours. The residue obtained after the reaction mixture was distilled off under reduced pressure was subjected to silica gel column chromatography (developing solvent; methanol: chloroform = 1: 9) to give 5-methyl-7- (2-chloroacetylamino) [1.2. 4] Triazolo [1,5-a] pyrimidine was obtained.
Melting point 165-175 ° C.
[0021]
(4) A mixture of the compound (2.4 g) obtained in (3), tetradecyl mercaptan (2.9 g), potassium carbonate (4.4 g) and acetone (50 ml) was heated to reflux for 2 hours under an argon atmosphere. . The reaction mixture was poured into water and extracted with methylene chloride. The methylene chloride layer was washed with saturated brine, dried over anhydrous magnesium sulfate, and methylene chloride was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography (developing solvent; ethyl acetate: hexane = 50: 50) to give 5-methyl-7- (2-tetradecylthioacetylamino) [1.2.4] triazolo [1,5 -A] Pyrimidine (compound 1) was obtained (2.78 g).
Melting point 85-86 ° C.
[0022]
Example 2
(1) Triethylamine (6.1 ml) was added to a mixture of the compound (7.42 g) obtained in Example 1 (2), 2-bromo-2-methylpropionyl bromide (5.4 ml) and chloroform (350 ml) under ice cooling. Was dripped. The reaction mixture was stirred at room temperature for 1 hour and then distilled under reduced pressure. The residue was washed with water to give 5-methyl-7- (2-bromo-2-methylpropionylamino) [1.2.4] triazolo [1,5. -A] Pyrimidine (5.65 g) was obtained.
Melting point 115-116 ° C.
[0023]
(2) Tetradecyl mercaptan (2.0 g) was added to 60% sodium hydride (0.3 g) suspended in 2-propanol (40 ml) to obtain a clear solution. This solution was added dropwise at room temperature into a mixture of the compound (2.0 g) obtained in (1) above and 2-propanol (40 ml). After the reaction mixture was distilled under reduced pressure, 3% hydrochloric acid and methylene chloride were added to the residue and stirred. The methylene chloride layer was washed with saturated brine, dried over anhydrous magnesium sulfate, and methylene chloride was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography (developing solvent; methanol: methylene chloride = 5: 95) to give 5-methyl-7- (2-tetradecylthio-2-methylpropionylamino) [1.2.4] triazolo. [1,5-a] pyrimidine (Compound 2) was obtained.
Melting point 58-60 ° C.
[0024]
Example 3
(1) A mixture of ethyl 2-methylacetoacetate (25.8 g), 3-amino-1,2,4 triazole (14.3 g) and acetic acid (200 ml) was stirred with heating under reflux for 7 hours. The reaction mixture was allowed to cool and the precipitated crystals were collected by filtration to give 7-hydroxy-5,6-dimethyl [1.2.4] triazolo [1,5-a] pyrimidine (15.9 g).
Melting point 300 ° C or higher
¹ H-NMR (DMSO-d ₆ ) δ: 1.97 (s, 3H), 2.33 (s, 3H), 8.16 (s, 1H), 13.00 (br, 1H).
[0025]
(2) A mixture of the compound (23 g) obtained in (1) above and phosphorus oxychloride (45 ml) was stirred for 2 hours under heating and reflux, and then the reaction mixture was evaporated to dryness. Water and methylene chloride were added to the residue, the pH was adjusted to 11 with concentrated aqueous ammonia, and the insoluble material was filtered off. The methylene chloride layer was washed with saturated brine, dried over anhydrous magnesium sulfate, methylene chloride was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography (developing solvent; ethyl acetate: methylene chloride = 1: 1). 6-dimethyl-7-chloro [1.2.4] triazolo [1,5-a] pyrimidine (21.3 g) was obtained.
¹ H-NMR (DMSO-d ₆ ) δ: 2.41 (s, 3H), 2.65 (s, 3H), 8.60 (s, 1H).
[0026]
(3) A mixture of the compound obtained in (2) (15 g), 25% aqueous ammonia (168 ml) and 2-propanol (840 ml) was stirred at room temperature for 6 hours. The crystals precipitated when the reaction mixture was concentrated under reduced pressure were collected by filtration to give 5,6-dimethyl-7-amino [1.2.4] triazolo [1,5-a] pyrimidine (12.2 g). It was.
Melting point 158-160 ° C.
[0027]
(4) A mixture of 2- (tetradecylthio) acetic acid (0.433 g) and thionyl chloride (3 ml) was stirred at room temperature for 16 hours and then distilled under reduced pressure. Chloroform (50 ml), the compound obtained in (3) (0.244 g) and pyridine (0.15 ml) were sequentially added to the residue, and the mixture was stirred at room temperature for 16 hours. The reaction mixture was poured into water and extracted with ethyl acetate. The ethyl acetate layer was washed with saturated brine, dried over anhydrous magnesium sulfate, ethyl acetate was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography (developing solvent; ethyl acetate: methylene chloride = 1: 1). 6-dimethyl-7- (2-tetradecylthioacetylamino) [1.2.4] triazolo [1,5-a] pyrimidine (compound 3) was obtained.
Melting point 77-79 ° C.
[0028]
Example 4
(1) 2-Bromo-2-methylpropionyl bromide (1.24 ml) was added dropwise to a mixture of the compound (1.63 g) obtained in Example 3 (3) and pyridine (20 ml) under ice cooling. The reaction mixture was stirred under ice-cooling for 2 hours and then distilled under reduced pressure. The residue was washed with water, and 5,6-dimethyl7- (2-bromo-2-methylpropionylamino) [1.2.4] triazolo [ 1,5-a] pyrimidine (2.67 g) was obtained.
Melting point 158-160 ° C.
[0029]
(2) Tetradecyl mercaptan (2.4 ml) was added to 60% sodium hydride (0.384 g) suspended in 2-propanol (50 ml) to obtain a clear solution. This solution was added dropwise to a mixture of the compound obtained in (1) (2.5 g) and tetrahydrofuran (40 ml) at room temperature. After the reaction mixture was distilled under reduced pressure, 3% hydrochloric acid and methylene chloride were added to the residue and stirred. The methylene chloride layer was washed with saturated brine, dried over anhydrous magnesium sulfate, methylene chloride was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography (developing solvent; methanol: chloroform = 3: 97) to give 5.6. -Dimethyl-7- (2-tetradecylthio-2-methylpropionylamino) [1.2.4] triazolo [1,5-a] pyrimidine (compound 4) was obtained.
Melting point 86-88 ° C.
[0030]
Example 5
(1) A mixture of diethyl 2-methylmalonate (26.3 g), 3-amino-1,2,4 triazole (12.7 g), sodium ethoxide (10.8 g) and ethanol (330 ml) was heated to reflux. For 7 hours. After the reaction mixture was allowed to cool, the precipitated crystals were collected by filtration and added to water to obtain a clear solution. Concentrated hydrochloric acid was added to this aqueous solution to adjust the pH to 1, and the precipitated crystals were collected by filtration, washed with water, and 5,7-dihydroxy-6-methyl [1.2.4] triazolo [1,5-a] pyrimidine (7. 87 g) was obtained.
Melting point 300 ° C or higher
¹ H-NMR (DMSO-d ₆ ) δ: 1.85 (s, 3H), 8.59 (s, 1H), 12.25 (br, 1H).
[0031]
(2) A mixture of the compound (7.68 g) obtained in (1) above and phosphorus oxychloride (50 ml) was stirred with heating under reflux for 2 hours, and then the reaction mixture was evaporated to dryness. Water and methylene chloride were added to the residue, then saturated sodium hydrogen carbonate solution was added to make the solution weakly alkaline, and insoluble matter was filtered off. The methylene chloride layer was washed with saturated brine, dried over anhydrous magnesium sulfate, methylene chloride was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography (developing solvent; ethyl acetate: methylene chloride = 1: 4). 7-Dichloro-6-methyl [1.2.4] triazolo [1,5-a] pyrimidine (6.86 g) was obtained.
Melting point: 147-149 ° C.
[0032]
(3) A mixture of the compound (1 g) obtained in (2), 25% aqueous ammonia (19.7 ml) and 2-propanol (10 ml) was stirred at room temperature for 16 hours. Crystals precipitated when the reaction mixture was concentrated under reduced pressure were collected by filtration to give 7-amino-5-chloro-6-methyl [1.2.4] triazolo [1,5-a] pyrimidine (0.805 g). Got.
Melting point 300 ° C or higher
¹ H-NMR (DMSO-d ₆ ) δ: 2.23 (s, 3H), 8.30 (br, 2H), 8.44 (s, 1H).
[0033]
(4) A mixture of the compound (0.184 g) obtained in (3) above and morpholine (5 ml) was stirred at 100 ° C. for 3 hours. The reaction mixture was allowed to cool and the precipitated crystals were collected by filtration and washed with chloroform to give 7-amino-5-morpholino-6-methyl [1.2.4] triazolo [1,5-a] pyrimidine (0.165 g). Obtained.
Melting point 300 ° C or higher
¹ H-NMR (DMSO-d ₆ ) δ: 2.06 (s, 3H), 3.17 (m, 4H), 3.73 (m, 4H), 7.47 (br, 2H), 8. 22 (s, 1H).
[0034]
(5) A mixture of 2- (tetradecylthio) acetic acid (0.124 g) and thionyl chloride (2 ml) was stirred at room temperature for 16 hours and then distilled under reduced pressure. Chloroform (50 ml), the compound obtained in (4) (0.244 g) and diisopropylethylamine (0.1 ml) were sequentially added to the residue, and the mixture was stirred at room temperature for 2 hours. The reaction mixture was poured into water and extracted with ethyl acetate. The ethyl acetate layer was washed with saturated brine, dried over anhydrous magnesium sulfate, ethyl acetate was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography (developing solvent; ethyl acetate: methylene chloride = 1: 1) to give 6- Methyl-5-morpholino-7- (2-tetradecylthioacetylamino) [1.2.4] triazolo [1,5-a] pyrimidine (Compound 5) was obtained.
Melting point 60-66 ° C.
[0035]
Example 6
(1) 2-Bromo-2-methylpropionyl bromide (0.95 ml) was added dropwise to a mixture of the compound (1.8 g) obtained in Example 5 (4) and pyridine (30 ml) under ice cooling. The reaction mixture was stirred under ice cooling for 2 hours and then distilled under reduced pressure. The residue was washed with water to give 6-methyl-5-morpholino-7- (2-bromo-2-methylpropionylamino) [1.2.4. ] Triazolo [1,5-a] pyrimidine (1.77 g) was obtained.
Melting point 152.5-154 ° C.
[0036]
(2) Tetradecyl mercaptan (1.0 g) was added to 60% sodium hydride (0.192 g) suspended in 2-propanol (30 ml) to obtain a clear solution. This solution was added dropwise at room temperature into a mixture of the compound (1.7 g) obtained in (1) above and 2-propanol (10 ml). After the reaction mixture was distilled under reduced pressure, 3% hydrochloric acid and methylene chloride were added to the residue and stirred. The methylene chloride layer was washed with saturated brine, dried over anhydrous magnesium sulfate, methylene chloride was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography (developing solvent; methanol: chloroform = 3: 97) to give 6-methyl. -5-morpholino-7- (2-tetradecylthio-2-methylpropionylamino) [1.2.4] triazolo [1,5-a] pyrimidine (Compound 6) was obtained.
Melting point 49-52 ° C.
[0037]
Example 7
(1) A mixture of diethyl 2-isopropylmalonate (75.9 g), 3-amino-1,2,4 triazole (29.67 g), sodium ethoxide (30.3 g) and ethanol (760 ml) was heated to reflux. For 6 hours. The reaction mixture was allowed to cool and the precipitated crystals were collected by filtration and added to water to give a clear solution. Concentrated hydrochloric acid was added to this aqueous solution to adjust the pH to 1, and the precipitated crystals were collected by filtration, washed with water, and washed with 5,7-dihydroxy-6-isopropyl [1.2.4] triazolo [1,5-a] pyrimidine (5. 94 g) was obtained.
Melting point 283-285 [deg.] C.
[0038]
(2) A mixture of the compound (6.0 g) obtained in (1) above and phosphorus oxychloride (40 ml) was stirred for 4 hours with heating under reflux, and then the reaction mixture was evaporated to dryness. Water and methylene chloride were added to the residue, then saturated sodium hydrogen carbonate solution was added to make the solution weakly alkaline, and insoluble matter was filtered off. The methylene chloride layer was washed with saturated brine, dried over anhydrous magnesium sulfate, methylene chloride was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography (developing solvent; ethyl acetate: methylene chloride = 1: 4). 7-Dichloro-6-isopropyl [1.2.4] triazolo [1,5-a] pyrimidine (4.07 g) was obtained.
Melting point: 140.5-142 ° C.
[0039]
(3) A mixture of the compound obtained in (2) (3.9 g), 25% aqueous ammonia (4.7 ml) and 2-propanol (150 ml) was stirred at room temperature for 16 hours. Crystals precipitated when the reaction mixture was concentrated under reduced pressure were collected by filtration to give 7-amino-5-chloro-6-isopropyl [1.2.4] triazolo [1,5-a] pyrimidine (3.25 g). Got.
Melting point 300 ° C or higher
¹ H-NMR (DMSO-d ₆ ) δ: 1.34 (d, J = 6 Hz, 6H), 3.50 (m, 1H), 8.20 (br, 2H), 8.46 (s, 1H ).
[0040]
(4) A mixture of the compound (3.1 g) obtained in (3) and morpholine (50 ml) was stirred at 120 ° C. for 3 hours. The reaction mixture was allowed to cool and the precipitated crystals were collected by filtration and washed with chloroform to give 7-amino-5-morpholino-6-isopropyl [1.2.4] triazolo [1,5-a] pyrimidine (3.34 g). Obtained.
Melting point 300 ° C or higher
¹ H-NMR (DMSO-d ₆ ) δ: 1.33 (d, J = 6 Hz, 6H), 3.08 (m, 4H), 3.36 (m, 1H), 3.75 (m, 4H) ), 7.28 (s, 2H), 8.30 (s, 1H).
[0041]
(5) A mixture of 2- (tetradecylthio) acetic acid (1.44 g) and thionyl chloride (10 ml) was stirred at room temperature for 16 hours and then distilled under reduced pressure. Chloroform (50 ml), the compound obtained in (4) (1.31 g) and diisopropylethylamine (1.0 ml) were sequentially added to the residue, and the mixture was stirred at room temperature for 2 hours. The reaction mixture was poured into water and extracted with ethyl acetate. The ethyl acetate layer was washed with saturated brine, dried over anhydrous magnesium sulfate, ethyl acetate was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography (developing solvent; ethyl acetate: methylene chloride = 3: 2) to give 6- Isopropyl-5-morpholino-7- (2-tetradecylthioacetylamino) [1.2.4] triazolo [1,5-a] pyrimidine (Compound 7) was obtained.
Melting point: 125.5-127.5 ° C.
[0042]
Test example [ACAT inhibitory effect]
The test was conducted according to the method described in J. Lipid Res. 22, 271 (1981).
The rabbit small intestine microsomal fraction was prepared according to a conventional method, and the obtained microsomal fraction was prepared by adding 0.0N normal phosphate containing 0.1N sucrose, 0.03N ethylenediaminetetraacetic acid (EDTA) and 0.05N potassium chloride. Suspended in potassium buffer (pH 7.4).
The test drug used was the compound obtained in Example 6 and 5-methyl-7-diethylamino [1.2.4] triazolo [1,5-a] pyrimidine (Japanese Patent Laid-Open No. 56-108772) as a comparative drug. Were dissolved in dimethyl sulfoxide, respectively. The rabbit small intestinal microsome fraction suspension 0.05N phosphate buffer containing 1% bovine serum albumin (pH 7.4) (250 [mu] g as protein amount) was added [1- ¹⁴ C] oleyl CoA, further to Various concentrations of test drug were added to make the total volume 500 μl. After incubating this mixture at 37 ° C. for 6 minutes, a mixture of chloroform and methanol (mixing ratio = 2: 1) was added to stop the reaction. After stirring, the chloroform layer was collected and concentrated to dryness. To this was added 30 μl of a solution of cholesterol oleate in chloroform (concentration 10 mg / ml), spotted on a silica gel thin layer plate (Merck Kieselgel 60F ₂₅₄ Art5715), and mixed with hexane and ethyl acetate (mixing ratio = 100: 3). Expanded. The portion corresponding to cholesterol oleate was scraped, and the radioactivity was measured with a liquid scintillation counter (ALSC LSC-3000), and the inhibition rate of ACAT activity was determined using the following formula to calculate the IC ₅₀ value.
[0043]
[Expression 1]

[0044]
As a result, the IC ₅₀ value of the compound obtained in Example 6 was 6.05 × 10 ⁻⁶ M.
[0045]
5-Methyl-7-diethylamino [1.2.4] triazolo [1,5-a] pyrimidine (a compound described in JP-A-56-108772) used as a control drug was 1 × 10 ^−4. Even at a concentration of M, no ACAT inhibitory activity was exhibited.

Claims (1)

formula

(In the formula, A represents an alkylene group having 1 to 4 carbon atoms, R ¹ represents an alkyl group having 1 to 20 carbon atoms, and R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. , R ³ represents a methyl group or a morpholino group.) A triazolopyrimidine derivative represented by: