JPH02292270A - Production of benzoxazoles - Google Patents
Production of benzoxazolesInfo
- Publication number
- JPH02292270A JPH02292270A JP11445789A JP11445789A JPH02292270A JP H02292270 A JPH02292270 A JP H02292270A JP 11445789 A JP11445789 A JP 11445789A JP 11445789 A JP11445789 A JP 11445789A JP H02292270 A JPH02292270 A JP H02292270A
- Authority
- JP
- Japan
- Prior art keywords
- formula
- group
- integer
- phosphorus pentoxide
- compound
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 150000000183 1,3-benzoxazoles Chemical class 0.000 title claims description 7
- 238000004519 manufacturing process Methods 0.000 title claims description 7
- 150000001875 compounds Chemical class 0.000 claims abstract description 13
- YWEUIGNSBFLMFL-UHFFFAOYSA-N diphosphonate Chemical compound O=P(=O)OP(=O)=O YWEUIGNSBFLMFL-UHFFFAOYSA-N 0.000 claims abstract description 8
- DLYUQMMRRRQYAE-UHFFFAOYSA-N phosphorus pentoxide Inorganic materials O1P(O2)(=O)OP3(=O)OP1(=O)OP2(=O)O3 DLYUQMMRRRQYAE-UHFFFAOYSA-N 0.000 claims abstract description 8
- 125000003118 aryl group Chemical group 0.000 claims abstract description 5
- 125000004442 acylamino group Chemical group 0.000 claims abstract description 4
- 125000003545 alkoxy group Chemical group 0.000 claims abstract description 4
- 125000000217 alkyl group Chemical group 0.000 claims abstract description 4
- 125000004104 aryloxy group Chemical group 0.000 claims abstract description 4
- 125000003917 carbamoyl group Chemical group [H]N([H])C(*)=O 0.000 claims abstract description 4
- 125000005843 halogen group Chemical group 0.000 claims abstract description 4
- 239000000126 substance Substances 0.000 claims abstract description 4
- 238000006243 chemical reaction Methods 0.000 claims description 17
- 125000000449 nitro group Chemical group [O-][N+](*)=O 0.000 claims 1
- 238000000034 method Methods 0.000 abstract description 15
- 239000002904 solvent Substances 0.000 abstract description 3
- 239000003905 agrochemical Substances 0.000 abstract description 2
- 239000003814 drug Substances 0.000 abstract description 2
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 abstract 3
- JCXJVPUVTGWSNB-UHFFFAOYSA-N Nitrogen dioxide Chemical group O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 abstract 1
- 150000004945 aromatic hydrocarbons Chemical class 0.000 abstract 1
- 229910052736 halogen Inorganic materials 0.000 abstract 1
- 238000010438 heat treatment Methods 0.000 abstract 1
- 150000002894 organic compounds Chemical class 0.000 abstract 1
- LMBFAGIMSUYTBN-MPZNNTNKSA-N teixobactin Chemical compound C([C@H](C(=O)N[C@@H]([C@@H](C)CC)C(=O)N[C@@H](CO)C(=O)N[C@H](CCC(N)=O)C(=O)N[C@H]([C@@H](C)CC)C(=O)N[C@@H]([C@@H](C)CC)C(=O)N[C@@H](CO)C(=O)N[C@H]1C(N[C@@H](C)C(=O)N[C@@H](C[C@@H]2NC(=N)NC2)C(=O)N[C@H](C(=O)O[C@H]1C)[C@@H](C)CC)=O)NC)C1=CC=CC=C1 LMBFAGIMSUYTBN-MPZNNTNKSA-N 0.000 abstract 1
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 9
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 9
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 8
- 229910052731 fluorine Inorganic materials 0.000 description 8
- 239000011737 fluorine Substances 0.000 description 8
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 7
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- 239000002253 acid Substances 0.000 description 6
- -1 etc.) Chemical group 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 230000002194 synthesizing effect Effects 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 4
- 150000002148 esters Chemical class 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 238000003786 synthesis reaction Methods 0.000 description 4
- CDAWCLOXVUBKRW-UHFFFAOYSA-N 2-aminophenol Chemical class NC1=CC=CC=C1O CDAWCLOXVUBKRW-UHFFFAOYSA-N 0.000 description 3
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 3
- 229960000583 acetic acid Drugs 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 2
- 150000001408 amides Chemical class 0.000 description 2
- RDOXTESZEPMUJZ-UHFFFAOYSA-N anisole Chemical compound COC1=CC=CC=C1 RDOXTESZEPMUJZ-UHFFFAOYSA-N 0.000 description 2
- 239000007810 chemical reaction solvent Substances 0.000 description 2
- MVPPADPHJFYWMZ-UHFFFAOYSA-N chlorobenzene Chemical compound ClC1=CC=CC=C1 MVPPADPHJFYWMZ-UHFFFAOYSA-N 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 239000012024 dehydrating agents Substances 0.000 description 2
- 238000006297 dehydration reaction Methods 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 239000005457 ice water Substances 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 2
- 229920000137 polyphosphoric acid Polymers 0.000 description 2
- 238000010189 synthetic method Methods 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- BCMCBBGGLRIHSE-UHFFFAOYSA-N 1,3-benzoxazole Chemical compound C1=CC=C2OC=NC2=C1 BCMCBBGGLRIHSE-UHFFFAOYSA-N 0.000 description 1
- RTZZCYNQPHTPPL-UHFFFAOYSA-N 3-nitrophenol Chemical compound OC1=CC=CC([N+]([O-])=O)=C1 RTZZCYNQPHTPPL-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- NSUQCZRASCOCLD-UHFFFAOYSA-L [O-]OOO[O-].[Li+].[Li+] Chemical compound [O-]OOO[O-].[Li+].[Li+] NSUQCZRASCOCLD-UHFFFAOYSA-L 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 125000004429 atom Chemical group 0.000 description 1
- SOMSXRFNBORXAU-UHFFFAOYSA-N benzene toluene Chemical compound C1=CC=CC=C1.CC1=CC=CC=C1.CC1=CC=CC=C1 SOMSXRFNBORXAU-UHFFFAOYSA-N 0.000 description 1
- 244000309464 bull Species 0.000 description 1
- 125000001309 chloro group Chemical group Cl* 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 239000012362 glacial acetic acid Substances 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 239000000543 intermediate Substances 0.000 description 1
- UZKWTJUDCOPSNM-UHFFFAOYSA-N methoxybenzene Substances CCCCOC=C UZKWTJUDCOPSNM-UHFFFAOYSA-N 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 239000012046 mixed solvent Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 238000005580 one pot reaction Methods 0.000 description 1
- 238000006798 ring closing metathesis reaction Methods 0.000 description 1
- 238000007142 ring opening reaction Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 125000001424 substituent group Chemical group 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
Landscapes
- Heterocyclic Carbon Compounds Containing A Hetero Ring Having Nitrogen And Oxygen As The Only Ring Hetero Atoms (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、医薬品や農薬及び写真用有典化合物の中間体
として有用な、２位に含フッ素アルキル置換基を有する
ベンゾオキサゾール類を安価に収率良く製造する方法に
関するものである．（従来の技術）
従来、２位に含フッ素アルキル置換基を有するベンゾオ
キサゾール類の合成方法としては、米国特許第４．１２
０．８６３に氷酢酸の存在下へキサク口ロイソブ口バノ
ール中、２−アミノフェノール類と含フッ素アルキルイ
ミド酸エステルを反応させる方法が記載されている．ま
た、米国特許第３，５６５，９０８には、酢酸とトリフ
ロ口酢酸中又はヘブタフ口口ブタン酸中、２−アミノフ
ェノール類と含フッ素アルキルイミド酸エステルを反応
させる方法が記載されている。しかし、これらの方法て
は含フッ素アルキルイミド酸エステルを合成しなければ
ならないため反応工程数が増える欠点を有している。別
法として、米国特許第３．５６５，９０８には、２一含
フン素置換アシルアミノフェノールの脱水による閉環を
、脱水剤としてポリリン酸を使用して２００℃の温度で
反応する方法が記載されている，また、ブリテイン・オ
ブ・ザ・ケミカルソサイエティー・オブ・ジャパン１９
７７年、２１６４ 〜２１６７頁（Ｂｕｌｌ．Ｃｈｅｍ
．Ｓｏｃｊｐｎ．２１６４〜２１６７ （１９７７））
には、同じく２一含フン素置換アシルアミノフェノール
を、脱水剤として五酸化リンを用いて２００〜２３０℃
の温度で反応を行う方法が記載されている。しかし、こ
れらの方法は反応溶媒を使用していないため、反応液が
粘稠あるいは固化してしまうため攪拌が充分に行えない
ことや、反応温度が２ ０ ０ ’Ｃ以上と高いことな
ど製造上の困難な問題を有していた。Detailed Description of the Invention (Field of Industrial Application) The present invention is to produce benzoxazoles having a fluorine-containing alkyl substituent at the 2-position, which are useful as intermediates for pharmaceuticals, agricultural chemicals, and classical compounds for photography, at low cost. This relates to a method for manufacturing with good yield. (Prior Art) Conventionally, as a method for synthesizing benzoxazoles having a fluorine-containing alkyl substituent at the 2-position, US Pat.
0.863 describes a method in which 2-aminophenols and fluorine-containing alkylimidic acid esters are reacted in dichloromethane in the presence of glacial acetic acid. Further, US Pat. No. 3,565,908 describes a method of reacting a 2-aminophenol with a fluorine-containing alkylimidic acid ester in acetic acid and trifloacetic acid or hebutafbutanoic acid. However, these methods have the disadvantage that the number of reaction steps increases because a fluorine-containing alkylimidic acid ester must be synthesized. Alternatively, U.S. Pat. No. 3,565,908 describes a method for ring closure by dehydration of a fluorine-substituted acylaminophenol at a temperature of 200° C. using polyphosphoric acid as the dehydrating agent. Also, the Bulletin of the Chemical Society of Japan 19
77, pp. 2164-2167 (Bull. Chem
．． Socjpn. 2164-2167 (1977))
Similarly, 2-fluorine-substituted acylaminophenol was heated at 200 to 230°C using phosphorus pentoxide as a dehydrating agent.
A method is described in which the reaction is carried out at a temperature of . However, since these methods do not use a reaction solvent, there are manufacturing problems such as the reaction solution becoming viscous or solidified and therefore not being sufficiently stirred, and the reaction temperature being as high as 200'C or higher. had a difficult problem.
（発明が解決しようとする課Ｈ）
前述のように、これまでの２位に含フン素アルキル置換
基を有するベンゾオキサゾール類の合成方法の問題点と
して、２−アミンフェノールと含フン素アルキルイミド
酸エステルの反応では反応工程が長いことが挙げられる
．また、２一含フ・７素置換アシルアミノフェノールの
ポリリン酸又は五酸化リンを用いた脱水反応では、反応
液の粘稠性や固化のため撹拌効率が悪いこと及び反応温
度が２００℃以上と高いことが問題であった。このため
温和な反応条件で高収率で！！！造する方法の開発が望
まれていた。(Problem H to be Solved by the Invention) As mentioned above, as a problem in the conventional method for synthesizing benzoxazoles having a fluorine-containing alkyl substituent at the 2-position, there are One problem with acid ester reactions is that the reaction process is long. In addition, in the dehydration reaction of polyphosphoric acid or phosphorus pentoxide of 21-fluorine-containing 7-substituted acylaminophenols, the stirring efficiency is poor due to the viscosity and solidification of the reaction solution, and the reaction temperature is higher than 200°C. The problem was that it was expensive. This allows for high yields under mild reaction conditions! ! ! There was a desire to develop a method for building
（課題を解決するための手段）
本発明者は、２位に含フン素アルキル置換基を有するベ
ンゾオキサゾール類の合成法について鋭意研究した結果
、以下に述べる方法を見出し本発明を完成した。(Means for Solving the Problems) As a result of intensive research into a method for synthesizing benzoxazoles having a fluorine-containing alkyl substituent at the 2-position, the present inventor discovered the method described below and completed the present invention.
本発明の目的は、下記式（１）で表わされる２−アミド
フェノール類から、五酸化リンの存在下、５０〜１ ６
０ ’Ｃの反応温度において、下記式（ＩＩ）で表わ
される化合物を合成することを特徴とするベンゾオキサ
ゾール類の製造方法によって達成された．
式中、ｎは１ないし４の整数を表わし、ｌは２以上２ｎ
＋１以下の整数を表わし、ｍは０もしくは整数を表わす
。但し、ｆｆｉ＋ｍ＝２ｎ＋１とする．Ｒはハロゲン原
子、二トロ基、アルキル基、アルコキシ基、アリール基
、アリールオキシ基、アシルアミノ基、カルバモイル基
を表わしａはＯないし３の整数を表わす。The object of the present invention is to prepare 2-amidophenols represented by the following formula (1) from 50 to 16
This was achieved by a method for producing benzoxazoles, which is characterized by synthesizing a compound represented by the following formula (II) at a reaction temperature of 0'C. In the formula, n represents an integer from 1 to 4, and l is 2 or more and 2n
It represents an integer less than or equal to +1, and m represents 0 or an integer. However, ffi+m=2n+1. R represents a halogen atom, a ditro group, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an acylamino group, or a carbamoyl group, and a represents an integer of O to 3.
本発明の構成についてさらに詳しく以下に説明する。The configuration of the present invention will be explained in more detail below.
一般式（１）及び（■）において、Ｒで表わされる置換
基の例としてはハロゲン原子（例えばクロル原子、プロ
ム原子など）、アルキル基（例えばメチル、エチル、ｔ
−ブチル）、アルコキシ基（例えばメトキシ、エトキシ
）、アリール基（例えばフエニル、置換フェニル）、ア
リールオキシ基（例えばフエニルオキシ、置換フェニル
オキシ）、アシルアミノ基（例えばアセトアミド、ピバ
ロイルアミノ）、カルバモイル基（例えばＮＮ−ジメチ
ルカルバモイル、Ｎ一エチル力ルバモイル）が挙げられ
る。In general formulas (1) and (■), examples of the substituent represented by R include halogen atoms (e.g. chloro atom, prom atom, etc.), alkyl groups (e.g. methyl, ethyl, t
-butyl), alkoxy groups (e.g. methoxy, ethoxy), aryl groups (e.g. phenyl, substituted phenyl), aryloxy groups (e.g. phenyloxy, substituted phenyloxy), acylamino groups (e.g. acetamido, pivaloylamino), carbamoyl groups (e.g. NN- dimethylcarbamoyl, N-ethylcarbamoyl).
次に本発明により合成できる一般式（ＩＩ）で示される
化合物の具体例を以下に示す。但しこれらに限定される
わけではない。Next, specific examples of the compound represented by the general formula (II) that can be synthesized according to the present invention are shown below. However, it is not limited to these.
Ｃ２
次に本発明を構成する合成方法における反応条件につい
て詳しく説明する．
本発明に用いられる反応溶媒としては、好ましくは芳香
族、炭化水素（例えばベンゼントルエン、クロルベンゼ
ン、アニソール、キシレン）であり、化合物の種類によ
り適宜選択され、本発明において、反応温度は５ ０
’Ｃないし１ ６ ０ ’Ｃ好ましくは８０℃ないし１
４０℃であり、化合物の種類によって適宜選択される．
五酸化りんの使用量は、−ｉ式（１）で示される化合物
に対してモル比で１／３モルないし１０モル、好ましく
は１／３モルないし等モルである。C2 Next, the reaction conditions in the synthetic method constituting the present invention will be explained in detail. The reaction solvent used in the present invention is preferably aromatic or hydrocarbon (for example, benzenetoluene, chlorobenzene, anisole, xylene), and is appropriately selected depending on the type of compound.
'C to 160'C preferably 80℃ to 1
The temperature is 40°C and is appropriately selected depending on the type of compound. The amount of phosphorus pentoxide used is 1/3 mol to 10 mol, preferably 1/3 mol to equimolar, relative to the compound represented by the -i formula (1).
以下に本発明の代表的な化合物例について具体的な合成
法を述べる．他の化合物も、同様の方法により合成でき
る．
（Ｘ施例）
以下に本発明ｔこより実施した２位にフン素置換アルキ
ル基を有するペンゾトリアゾール類の代表的合成例につ
いて具体的に示す。Specific synthetic methods for representative examples of compounds of the present invention are described below. Other compounds can also be synthesized by similar methods. EXAMPLE
例（＋） ５−クロロ−２−ヘプタフ口ロプロビルー
６〜ニトロヘンゾトリアゾールの合成（例示化合物（４
）の合成）
４−クロロ−２−へブタフルオロ酪酸アミドー５−ニト
ロフェノール１０ｇ （０．０２６モル）・および五酸
化リン１．８ｇ （０．０１３モル）をトルエン３０Ｗ
１に加えた．１１０’Ｃないし１１５℃にて７時間撹拌
した後、氷冷し内温を２０℃とした。反応液を氷水２０
０−に加え、酢エチ５〇一で抽出した。酢エチ、トルエ
ン層を３回水洗し中性とした。抽出、水洗は生成したベ
ンゾオキサゾールの加水分解による開環を抑えるため２
０℃以下で行った，無水芒硝で乾燥後、溶媒を減圧下で
留去した。油状物をメタノール１５ｍｆと水Ｉ５一の混
合ｔ容媒で再結晶することにより目的とする５−クロロ
ー２−へブタフルオロブ口ピル−６一ニト口ベンゾオキ
サゾール７．１ｇを得た。収率７４．５％、融点は７３
〜７４℃であった。Example (+) Synthesis of 5-chloro-2-heptafoloprovir-6-nitrohenzotriazole (Illustrative compound (4)
) Synthesis of 4-chloro-2-hebutafluorobutyric acid amide 5-nitrophenol (10 g (0.026 mol) and 1.8 g (0.013 mol) of phosphorus pentoxide in toluene 30W)
Added to 1. After stirring at 110'C to 115°C for 7 hours, the mixture was cooled with ice to bring the internal temperature to 20°C. Pour the reaction solution into ice water for 20 minutes.
0- and extracted with ethyl acetate 501. The acetic acid and toluene layers were washed with water three times to make them neutral. Extraction and water washing were carried out in order to suppress ring opening due to hydrolysis of the benzoxazole produced.
After drying over anhydrous sodium sulfate at a temperature below 0°C, the solvent was distilled off under reduced pressure. The oil was recrystallized in a mixed medium of 15 mf of methanol and 15 mf of water to obtain 7.1 g of the desired 5-chloro-2-hebutafluorobutyl-6-nitobenzoxazole. Yield 74.5%, melting point 73
The temperature was ~74°C.
例（２） ２−へブタフルオ口プロピル−６−二トロ
ーベンゾオキサゾールの合成（例示化合物（２）の合成
）
２−へブタフルオロ酪酸アミドー５一二トロフェ／−ル
５ ｇ （０． ０ １ ４モル）および五酸化リ７
１．Ｏｇ （０．００７モル）をトル！７２０ｄに加え
た．１１０℃ないし１１５℃にて５時間攪拌した後、氷
冷し、内温を２ ０ ’Ｃとした．反応液を氷水１００
−に注ぎ、酢エチ３ｏ一を加え抽出した．酢エチ、トル
エン層を水洗し水性溶液とした。Example (2) Synthesis of 2-hebutafluoropropyl-6-nitrobenzoxazole (synthesis of exemplified compound (2)) 2-hebutafluorobutyric acid amide 5-ditrophenol 5 g (0.0 1 4 mole) and lithium pentoxide 7
1. Og (0.007 mol) tol! Added to 720d. After stirring at 110°C to 115°C for 5 hours, the mixture was cooled on ice and the internal temperature was brought to 20'C. Pour the reaction solution into ice water 100%
- and extracted by adding 3 o's of ethyl acetate. The ethyl acetate and toluene layers were washed with water to obtain an aqueous solution.
抽出、水洗は、２０゛ｃ以下で行った。無水芒硝で乾燥
後、溶媒を減圧下で留去した。油状物を、メタノール７
Ｒｌと水３Ｍ！の混合溶媒で再結晶することにより目的
とする２−ヘフ゜タフノレオロフ゜ロピル−６−二トロ
ベンゾオキサゾール３．１８ｔ−得た．収率は６５．３
％、融点は４９〜５ ０ ’Ｃであった．
（発明の効果）
上記実施例より明らかなように本発明はペンゾオキサヅ
ール類の簡便な合成法を提供する．すなわち、２−アミ
ドフェノール類から、一工程の反応のみで目的物を得る
ことができ、しかも反応温度が比較的低温のため、特別
な製造設備が不要である。従来の方法では、反応工程数
が多い、高温の反応条件が必要であるなど、製造コスト
が高く、適切な方法ではなかった。Extraction and water washing were performed at 20°C or less. After drying over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure. oil, methanol 7
Rl and water 3M! By recrystallizing with a mixed solvent of 3.18 t of the desired 2-heptafnoreolopyl-6-nitrobenzoxazole was obtained. Yield is 65.3
%, and the melting point was 49-50'C. (Effects of the Invention) As is clear from the above examples, the present invention provides a simple method for synthesizing penzoxadurins. That is, the desired product can be obtained from 2-amidophenols through a one-step reaction, and since the reaction temperature is relatively low, no special production equipment is required. Conventional methods require a large number of reaction steps and require high-temperature reaction conditions, resulting in high production costs and are not appropriate methods.
Claims (1)
、五酸化リンの存在下、５０〜１６０℃の反応温度にお
いて、下記式（II）で表わされる化合物を合成すること
を特徴とするベンゾオキサゾール類の製造方法。 式（ I ）▲数式、化学式、表等があります▼（II）▲
数式、化学式、表等があります▼ 式中、ｎは１ないし４の整数を表わし、ｌは２以上２ｎ
＋１以下の整数を表わし、ｍは０もしくは整数を表わす
。但し、ｌ＋ｍ＝２ｎ＋１とする。 Ｒはハロゲン原子、ニトロ基、アルキル基、アリール基
、アルコキシ基、アリールオキシ基、アシルアミノ基、
またはカルバモイル基を表わしａは０ないし３の整数を
表わす。ａが複数のとき、複数個のＲは同じものまたは
異なるものを表わす。[Claims] A compound represented by the following formula (II) is synthesized from a 2-amidophenol represented by the following formula (I) at a reaction temperature of 50 to 160°C in the presence of phosphorus pentoxide. Characteristic method for producing benzoxazoles. Formula (I) ▲ Contains mathematical formulas, chemical formulas, tables, etc. ▼ (II) ▲
There are mathematical formulas, chemical formulas, tables, etc. ▼ In the formula, n represents an integer from 1 to 4, and l is 2 or more and 2n
It represents an integer less than or equal to +1, and m represents 0 or an integer. However, l+m=2n+1. R is a halogen atom, a nitro group, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an acylamino group,
or a carbamoyl group, and a represents an integer of 0 to 3. When a is plural, the plural R's represent the same thing or different things.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11445789A JPH02292270A (en) | 1989-05-08 | 1989-05-08 | Production of benzoxazoles |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11445789A JPH02292270A (en) | 1989-05-08 | 1989-05-08 | Production of benzoxazoles |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02292270A true JPH02292270A (en) | 1990-12-03 |
Family
ID=14638210
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11445789A Pending JPH02292270A (en) | 1989-05-08 | 1989-05-08 | Production of benzoxazoles |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02292270A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5151523A (en) * | 1990-03-21 | 1992-09-29 | Basf Aktiengesellschaft | Preparation of 2-methylbenzoxazole |
-
1989
- 1989-05-08 JP JP11445789A patent/JPH02292270A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5151523A (en) * | 1990-03-21 | 1992-09-29 | Basf Aktiengesellschaft | Preparation of 2-methylbenzoxazole |
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