1
|
Nguyen LA, Phaenok S, Le DL, Nguyen TTT, Ngo QA, Nguyen TB. Fe/S-Catalyzed Redox Condensation of o-Nitrophenols with Isothiocyanates to 2-Aminobenzoxazoles. Org Lett 2023. [PMID: 37393601 DOI: 10.1021/acs.orglett.3c01897] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
As frequently encountered byproducts of isocyanate chemistry, hydrogen sulfide and related sulfur containing compounds should be treated in a safe way to lower their adverse health and environmental effects, especially in large scale syntheses. As a proof of concept, we report herein an example of in situ recycling of sulfur byproduct to reductant in the synthesis of bioactive 2-aminobenzoxazoles 3. Using an Fe/S catalytic system, this heterocyclic scaffold could be obtained from o-nitrophenols 1 with isothiocyates 2 via direct redox condensation consisting of reduction of the nitro group of 1 by the sulfur moiety of 2.
Collapse
Affiliation(s)
- Le Anh Nguyen
- Institute of Chemistry, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam
- Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam
| | - Supasorn Phaenok
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Sud, Université Paris-Saclay, 1, av de la Terrasse, 91198 Gif-sur-Yvette, France
| | - Duc Long Le
- Institute of Chemistry, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam
- Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam
| | - Thi Thu Tram Nguyen
- Department of Chemistry, Faculty of Basic Science, Can Tho University of Medicine and Pharmacy, Can Tho, Vietnam
| | - Quoc Anh Ngo
- Institute of Chemistry, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam
- Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam
| | - Thanh Binh Nguyen
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Sud, Université Paris-Saclay, 1, av de la Terrasse, 91198 Gif-sur-Yvette, France
| |
Collapse
|
2
|
Wu Q, Hou J, Gu Q, Gao H, Shi M, Zheng L. PhI(OAc) 2/Pd(OAc) 2 promoted the formation of 8-hydroxyquinoline derivatives from benzoxazoles and alcohols. Org Biomol Chem 2023; 21:1148-1152. [PMID: 36628966 DOI: 10.1039/d2ob01712a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A PhI(OAc)2/Pd(OAc)2 system that synergistically promotes the formation of 8-hydroxyquinoline derivatives from benzoxazoles and alcohols has been developed. The reaction proceeded smoothly with a range of benzoxazoles and alcohols to give the corresponding 8-hydroxyquinoline derivatives in moderate yields.
Collapse
Affiliation(s)
- Qingkun Wu
- School of Pharmacy, Jiangsu Ocean University, Lianyungang, China.
| | - Jingxuan Hou
- School of Pharmacy, Jiangsu Ocean University, Lianyungang, China.
| | - Qingshan Gu
- School of Pharmacy, Jiangsu Ocean University, Lianyungang, China.
| | - Hui Gao
- School of Pharmacy, Jiangsu Ocean University, Lianyungang, China.
| | - Meiqi Shi
- School of Pharmacy, Jiangsu Ocean University, Lianyungang, China.
| | - Lu Zheng
- School of Pharmacy, Jiangsu Ocean University, Lianyungang, China.
| |
Collapse
|
3
|
Racheeti PB, Gunturu RB, Pinapati SR, Kowthalam A, Tamminana R, Rudraraju R. Hypervalent iodine(III) promoted synthesis of isothiocyanates in water. SYNTHETIC COMMUN 2022. [DOI: 10.1080/00397911.2022.2148222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Ratna Babu Gunturu
- Department of Chemistry, Acharya Nagarjuna University, Guntur, AP, India
| | | | - Anitha Kowthalam
- Department of Chemistry, Sri Krishna Devaraya University, Ananthapur, AP, India
| | - Ramana Tamminana
- Department of Chemistry, VIT-AP University, Amaravati, AP, India
| | | |
Collapse
|
4
|
Ibrahim K, Saranya PV, Anilkumar G. Recent Advances and Prospects in the Amination of Benzoxazoles. ChemistrySelect 2022. [DOI: 10.1002/slct.202200601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Kaliyathodi Ibrahim
- School of Chemical Sciences Mahatma Gandhi University Priyadarsini Hills P O Kottayam Kerala INDIA 686560
| | - Padinjare Veetil Saranya
- School of Chemical Sciences Mahatma Gandhi University Priyadarsini Hills P O Kottayam Kerala INDIA 686560
| | - Gopinathan Anilkumar
- School of Chemical Sciences Mahatma Gandhi University Priyadarsini Hills P O Kottayam Kerala INDIA 686560
| |
Collapse
|
5
|
Long L, Jieyan W, Li X, Peng S, Qiao L, Luo G, Chen Z. Hypervalent Iodine(III) Promoted Tandem Reaction of o-Fluoroanilines with Formamides to Construct 2-Aminobenzoxazoles. Org Chem Front 2022. [DOI: 10.1039/d2qo00049k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A simple and practical synthesis of 2-aminobenzoxaoles has been developed from commercially available o-fluoroanilines, and formamides. The process can be performed in the absence of metal catalyst with high levels...
Collapse
|
6
|
Ghoshal T, Patel TM, Kotturi S. A facile electrochemical synthesis of suvorexant. Tetrahedron Lett 2021. [DOI: 10.1016/j.tetlet.2021.153014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
7
|
Guo L, Pan X, Yuan H. Synthesis of Anti-Insomnia Drug Suvorexant. HETEROCYCLES 2021. [DOI: 10.3987/com-21-14414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
8
|
Saetan T, Sukwattanasinitt M, Wacharasindhu S. A Mild Photocatalytic Synthesis of Guanidine from Thiourea under Visible Light. Org Lett 2020; 22:7864-7869. [PMID: 32986446 DOI: 10.1021/acs.orglett.0c02770] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
In this work, we developed the catalytic guanylation of thiourea using Ru(bpy)3Cl2 as a photocatalyst under irradiation by visible light. The conversion of various thioureas to the corresponding guanidines was achieved using 1-5 mol % of photocatalyst in a mixture of water and ethanol at room temperature. Key benefits of this reaction include the use of photoredox catalyst, low-toxicity solvents/base, ambient temperature, and an open-flask environment.
Collapse
Affiliation(s)
- Trin Saetan
- Nanotec-CU Center of Excellence on Food and Agriculture, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Mongkol Sukwattanasinitt
- Nanotec-CU Center of Excellence on Food and Agriculture, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Sumrit Wacharasindhu
- Nanotec-CU Center of Excellence on Food and Agriculture, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.,Green Chemistry for Fine Chemical Productions STAR, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok10330, Thailand
| |
Collapse
|
9
|
Amininia A, Pourshamsian K, Sadeghi B. Nano-ZnO Impregnated on Starch—A Highly Efficient Heterogeneous
Bio-Based Catalyst for One-Pot Synthesis of Pyranopyrimidinone and Xanthene Derivatives
as Potential Antibacterial Agents. RUSSIAN JOURNAL OF ORGANIC CHEMISTRY 2020. [DOI: 10.1134/s1070428020070234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
10
|
Zheng N, Liu C, Ding YN, Shi WY, Zhang BS, Liang YM. Copper-Catalyzed Three-Component Redox-Neutral Ring Opening of Benzothiazoles to 1-Amino- N-(2-(phenylthio)phenyl)methanimine. J Org Chem 2020; 85:7666-7673. [PMID: 32479726 DOI: 10.1021/acs.joc.9b03489] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Copper-catalyzed three-component redox-neutral ring opening of benzothiazoles with aryl iodides and O-benzoyl hydroxylamines for the synthesis of 1-amino-N-(2-(phenylthio)phenyl)methanimine has been developed. This one-pot reaction undergoes C-S and N-O bond cleavage and new C-S and C-N bond construction. Several control experiments excluded a free radical procedure and also demonstrated the secondary amine as a possible intermediate, which was vital to the catalytic reaction. Meanwhile, the deuteration experiment got rid of the C-H activation dehydroisomerization of the benzothiazole mechanism.
Collapse
Affiliation(s)
- Nian Zheng
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Ce Liu
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Ya-Nan Ding
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Wei-Yu Shi
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Bo-Sheng Zhang
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Yong-Min Liang
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, People's Republic of China
| |
Collapse
|
11
|
Pattarawarapan M, Wiriya N, Yimklan S, Wangngae S, Phakhodee W. Zwitterionic Ring-Opened Oxyphosphonium Species from the Ph 3P-I 2 Mediated Reactions of Benzo[ d]oxazol-2(3 H)-ones with Secondary Amines. J Org Chem 2020; 85:6151-6158. [PMID: 32242407 DOI: 10.1021/acs.joc.0c00211] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Instead of the expected substituted 2-aminobenzo[d]oxazoles, relatively stable ring-opened oxyphosphonium betaines were isolated for the first time from the Ph3P-I2-mediated reactions of benzo[d]oxazol-2(3H)-ones with acyclic secondary amines. The structure of one of these compounds was unambiguously confirmed by single-crystal X-ray analysis. Thermolysis of the betaines gave rise to 2-dialkylaminobenzoxazoles with concomitant loss of triphenylphosphine oxide, suggesting their possible role as intermediates in an alternative reaction path.
Collapse
Affiliation(s)
- Mookda Pattarawarapan
- Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.,Research Center on Chemistry for Development of Health Promoting Products from Northern Resources, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Nittaya Wiriya
- Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Saranphong Yimklan
- Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Sirilak Wangngae
- Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Wong Phakhodee
- Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.,Research Center on Chemistry for Development of Health Promoting Products from Northern Resources, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
| |
Collapse
|
12
|
Bozdag M, Supuran CT, Esposito D, Angeli A, Carta F, Monti SM, De Simone G, Alterio V. 2-Mercaptobenzoxazoles: a class of carbonic anhydrase inhibitors with a novel binding mode to the enzyme active site. Chem Commun (Camb) 2020; 56:8297-8300. [DOI: 10.1039/d0cc02857f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
2-Mercaptobenzoxazole represents an interesting lead compound alternative to the classical sulfonamides for the development of selective carbonic anhydrase inhibitors.
Collapse
Affiliation(s)
- Murat Bozdag
- Neurofarba Department
- Section of Pharmaceutical and Nutriceutical Sciences
- Università degli Studi di Firenze
- Sesto Fiorentino
- Florence
| | - Claudiu T. Supuran
- Neurofarba Department
- Section of Pharmaceutical and Nutriceutical Sciences
- Università degli Studi di Firenze
- Sesto Fiorentino
- Florence
| | | | - Andrea Angeli
- Neurofarba Department
- Section of Pharmaceutical and Nutriceutical Sciences
- Università degli Studi di Firenze
- Sesto Fiorentino
- Florence
| | - Fabrizio Carta
- Neurofarba Department
- Section of Pharmaceutical and Nutriceutical Sciences
- Università degli Studi di Firenze
- Sesto Fiorentino
- Florence
| | | | | | | |
Collapse
|
13
|
Zhang J, Chen L, Dong Y, Yang J, Wu Y. A Cu 2O/TBAB-promoted approach to synthesize heteroaromatic 2-amines via one-pot cyclization of aryl isothiocyanates with ortho-substituted amines in water. Org Biomol Chem 2020; 18:7425-7430. [PMID: 32936165 DOI: 10.1039/d0ob01431a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An efficient approach to synthesize heteroaromatic 2-amines from one-pot desulfurization/dehydrogenative cyclization of aryl isothiocyanates with ortho-substituted amines in water was developed. This approach tolerated a wide range of functional groups on the aromatic ring, providing a practical and environment-friendly process to synthesize heteroaromatic 2-amines in moderate to excellent yields. A plausible mechanism was proposed and the role of TBAB and Cu2O in the present strategy was suggested with the help of ESI mass spectrometry.
Collapse
Affiliation(s)
- Jinli Zhang
- Henan Key Laboratory of Chemical Biology and Organic Chemistry, Key Laboratory of Applied Chemistry of Henan Universities, Zhengzhou University, Zhengzhou, 450052, P.R. China. and College of Chemistry, Green Catalytic Center, Zhengzhou University, Zhengzhou 450001, P. R. China
| | - Ling Chen
- Henan Key Laboratory of Chemical Biology and Organic Chemistry, Key Laboratory of Applied Chemistry of Henan Universities, Zhengzhou University, Zhengzhou, 450052, P.R. China.
| | - Yibo Dong
- Henan Key Laboratory of Chemical Biology and Organic Chemistry, Key Laboratory of Applied Chemistry of Henan Universities, Zhengzhou University, Zhengzhou, 450052, P.R. China.
| | - Jinchen Yang
- College of Chemistry, Green Catalytic Center, Zhengzhou University, Zhengzhou 450001, P. R. China
| | - Yangjie Wu
- Henan Key Laboratory of Chemical Biology and Organic Chemistry, Key Laboratory of Applied Chemistry of Henan Universities, Zhengzhou University, Zhengzhou, 450052, P.R. China. and College of Chemistry, Green Catalytic Center, Zhengzhou University, Zhengzhou 450001, P. R. China
| |
Collapse
|
14
|
Šlachtová V, Chasák J, Brulíková L. Synthesis of Various 2-Aminobenzoxazoles: The Study of Cyclization and Smiles Rearrangement. ACS OMEGA 2019; 4:19314-19323. [PMID: 31763555 PMCID: PMC6868899 DOI: 10.1021/acsomega.9b02702] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 10/18/2019] [Indexed: 06/10/2023]
Abstract
This study reports two synthetic approaches leading to 2-aminobenzoxazoles and their N-substituted analogues. Our first synthetic strategy involves a reaction between various o-aminophenols and N-cyano-N-phenyl-p-toluenesulfonamide as a nonhazardous electrophilic cyanating agent in the presence of Lewis acid. The second synthetic approach uses the Smiles rearrangement upon activation of benzoxazole-2-thiol with chloroacetyl chloride. Both developed synthetic protocols are widely applicable, afford the desired aminobenzoxazoles in good to excellent yields, and use nontoxic and inexpensive starting material.
Collapse
|
15
|
Harry NA, Radhika S, Neetha M, Anilkumar G. Recent Advances and Prospects of Organic Reactions “On Water”. ChemistrySelect 2019. [DOI: 10.1002/slct.201903360] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Nissy Ann Harry
- School of Chemical Sciences, Mahatma Gandhi UniversityPriyadarsini Hills, Kottayam 686 560 Kerala INDIA
| | - Sankaran Radhika
- School of Chemical Sciences, Mahatma Gandhi UniversityPriyadarsini Hills, Kottayam 686 560 Kerala INDIA
| | - Mohan Neetha
- School of Chemical Sciences, Mahatma Gandhi UniversityPriyadarsini Hills, Kottayam 686 560 Kerala INDIA
| | - Gopinathan Anilkumar
- School of Chemical Sciences, Mahatma Gandhi UniversityPriyadarsini Hills, Kottayam 686 560 Kerala INDIA
- Advanced Molecular Materials Research Centre (AMMRC)Mahatma Gandhi University, Priyadarsini Hills, Kottayam Kerala 686 560 INDIA
| |
Collapse
|
16
|
Lv Z, Wang H, Quan Z, Gao Y, Lei A. Dioxygen-triggered oxidative cleavage of the C-S bond towards C-N bond formation. Chem Commun (Camb) 2019; 55:12332-12335. [PMID: 31556432 DOI: 10.1039/c9cc05707b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Research on the cleavage of C-C bonds has been well developed. By comparison with this, the activation of C-S bonds remains challenging. Herein, dioxygen-triggered oxidative cleavage of C-S bonds has been achieved, delivering a series of N-containing heterocyclic compounds that are frequently found in pesticides and pharmaceuticals. Additionally, the potential utility of this protocol was further demonstrated by a gram-scale experiment. Mechanistically, dioxygen plays a key role in the cleavage of C-S bonds towards C-N bond formation.
Collapse
Affiliation(s)
- Zongchao Lv
- Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, Hubei, P. R. China.
| | - Huamin Wang
- Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, Hubei, P. R. China.
| | - Zhicong Quan
- Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, Hubei, P. R. China.
| | - Yuan Gao
- Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, Hubei, P. R. China.
| | - Aiwen Lei
- Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, Hubei, P. R. China. and National Research Center for Carbohydrate Synthesis, Jiangxi Normal University, Nanchang 330022, Jiangxi, P. R. China
| |
Collapse
|
17
|
Srisa J, Tankam T, Sukwattanasinitt M, Wacharasindhu S. Micelle-Enabled One-Pot Guanidine Synthesis in Water Directly from Isothiocyanate using Hypervalent Iodine(III) Reagents under Mild Conditions. Chem Asian J 2019; 14:3335-3343. [PMID: 31397526 DOI: 10.1002/asia.201900982] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Indexed: 02/06/2023]
Abstract
In this work, we developed a one-pot synthesis of guanidine directly from isothiocyanate using DIB (diacetoxyiodobenzene) as a desulfurizing agent under micellar conditions in water. Our optimization study revealed that the use of 1 % TPGS-750-M as a surfactant with NaOH as an additive base at room temperature can convert a variety of isothiocyanates and amines into corresponding guanidines in excellent yields (69-95 %). This synthetic process in water can be applied to prepare guanidine at gram-scale quantity. Our aqueous micellar medium also demonstrated high reusability as the reaction can be performed for several cycles without losing its efficiency. The reaction is metal-free, utilizes water as solvent and practical (room temperature and open flask).
Collapse
Affiliation(s)
- Jakkrit Srisa
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.,Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Bangkok, Thailand
| | - Theeranon Tankam
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Mongkol Sukwattanasinitt
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.,Nanotec-CU Center of Excellence on Food and Agriculture, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Sumrit Wacharasindhu
- Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Bangkok, Thailand.,Nanotec-CU Center of Excellence on Food and Agriculture, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| |
Collapse
|
18
|
Pattarawarapan M, Yamano D, Wiriya N, Phakhodee W. Metal-Free Synthesis of 2- N, N-Dialkylaminobenzoxazoles Using Tertiary Amines as the Nitrogen Source. J Org Chem 2019; 84:6516-6523. [PMID: 31017442 DOI: 10.1021/acs.joc.9b00797] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The unprecedented reaction of tertiary amines with 2(3 H)-benzoxazolones has been investigated. In the presence of the Ph3P-I2 reagent system, the reaction of both acyclic and cyclic aliphatic tertiary amines led to the formation of 2- N, N-dialkylaminobenzoxazoles with the selective cleavage of an alkyl group. Especially, N-(2-iodoethyl)piperazinyl derivatives were rapidly produced in good yields when using DABCO as the nitrogen source. Only in the cases when the nucleophilicity of the substrates exceeds that of the amine, competitive self-condensation of benzoxazolones then proceeds preferentially. 31P{1H}-NMR study suggested the involvement of an aryloxyphosphonium intermediate and/or possibly 2-iodobenzoxazole which activates the C-2 position of benzoxazolones toward nucleophilic aromatic substitution.
Collapse
Affiliation(s)
- Mookda Pattarawarapan
- Department of Chemistry, Faculty of Science , Chiang Mai University , Chiang Mai 50200 , Thailand
- Research Center on Chemistry for Development of Health Promoting Products from Northern Resources, Faculty of Science , Chiang Mai University , Chiang Mai 50200 , Thailand
| | - Dolnapa Yamano
- Department of Chemistry, Faculty of Science , Chiang Mai University , Chiang Mai 50200 , Thailand
| | - Nitaya Wiriya
- Department of Chemistry, Faculty of Science , Chiang Mai University , Chiang Mai 50200 , Thailand
| | - Wong Phakhodee
- Department of Chemistry, Faculty of Science , Chiang Mai University , Chiang Mai 50200 , Thailand
- Research Center on Chemistry for Development of Health Promoting Products from Northern Resources, Faculty of Science , Chiang Mai University , Chiang Mai 50200 , Thailand
| |
Collapse
|