A fully continuous-flow diazotization–hydrolysis protocol has been developed for the preparation of p-cresol. This process started from the diazotization of p-toluidine to form diazonium intermediate. The reaction was then quenched by urea and subsequently followed by a hydrolysis to give the final product p-cresol. Three types of byproducts were initially found in this reaction sequence. After an optimization of reaction conditions (based on impurity analysis), side reactions were eminently inhibited, and a total yield up to 91% were ultimately obtained with a productivity of 388 g/h. The continuous-flow methodology was used to avoid accumulation of the highly energetic and potentially explosive diazonium salt to realize the safe preparation for p-cresol.

. ¹H NMR (400 MHz, (CD₃)₂SO) δ/ppm: 9.06 (br s, 1H, −OH), 6.94 (d, J = 8.0 Hz, 2H, Ar–H), 6.62 (d, J = 8.0 Hz, 2H, Ar–H), 2.17 (s, 3H, −CH₃).

¹³C NMR (CDCl₃) δ/ppm: 153.0, 129.9, 115.1, 20.5.

Literature data:(3b) ¹H NMR (300 MHz, CDCl₃) δ/ppm: 7.03 (d, J = 8.2 Hz, 2H), 6.73 (dd, J = 8.2, 2.0 Hz, 2H), 4.75 (s, 1H, OH), 2.27 (s, 3H, CH₃).

¹³C NMR (CDCl₃) δ/ppm: 153.2, 130.2, 115.2, 20.6.

3(b) Taniguchi, T.; Imoto, M.; Takeda, M.; Nakai, T.; Mihara, M.; Iwai, T.; Ito, T.; Mizuno, T.; Nomoto, A.; Ogawa, A. Heteroat. Chem. 2015, 26, 411– 416 DOI: 10.1002/hc.21275

 

A Fully Continuous-Flow Process for the Synthesis of p-Cresol: Impurity Analysis and Process Optimization

Zhiqun Yu†, Xin Ye†, Qilin Xu‡, Xiaoxuan Xie†, Hei Dong†, and Weike Su^*†‡ 

^†National Engineering Research Center for Process Development of Active Pharmaceutical Ingredients, Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, ^‡Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, P. R. China

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.7b00250

 

*Tel.: (+86)57188320899. E-mail: pharmlab@zjut.edu.cn.

http://pubs.acs.org/doi/full/10.1021/acs.oprd.7b00250

NMR PREDICT

 

1,2-Bis(3-methoxyphenyl)benzene

1,2-Bis(3-methoxyphenyl)benzene (5)

  

 1H NMR (500 MHz, DMSO-d6): δ 3.59 (s, 6H), 6.65 (dd, J = 2.5, 1.5 Hz, 2H), 6.70 (ddd, J = 7.5, 1.5, 1.0 Hz, 2H), 6.78 (ddd, J= 8.0, 2.5, 1.0 Hz, 2H), 7.16 (t, J = 8.0 Hz, 2H), 7.40–7.46 (m, 4H).

13C NMR (126 MHz, DMSO-d6): δ 54.8, 112.4, 115.0, 121.7, 127.7, 129.0, 130.2, 139.8, 142.4, 158.7.

HRMS (TOF MS EI+) for C20H18O2 [M]+: calcd 290.1307, found 290.1303.

Efficient and Practical Synthesis of Electron Transport Material and Its Key Intermediate

Xiangdong Zhao†, Guijie Li*† , Zhi-Qiang Zhu‡, Kun Fang†, Yuning Yang†, Jian Li‡ , and Yuanbin She*†

† State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, Zhejiang 310014, P. R. China

‡ Department of Materials Science and Engineering, Arizona State University, Tempe, Arizona 85284, United States

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.7b00280

*E-mail: guijieli@zjut.edu.cn., *E-mail: sheyb@zjut.edu.cn.

Abstract

An efficient and practical synthesis of 2,7-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)triphenylene 4 from two cheap commodity chemicals in five steps with a total yield of 48.6% was developed. This process had been successfully applied in the synthesis of electron transport material (ETM) BPyTP-2 in the gram scale with a total yield of 47.2%. This practical development of the key intermediate 4 opens a door in its further application in the synthesis of other triphenylene-based ETMs and host materials in the materials field.

/////////////http://pubs.acs.org/doi/10.1021/acs.oprd.7b00280

http://pubs.acs.org/doi/suppl/10.1021/acs.oprd.7b00280/suppl_file/op7b00280_si_001.pdf

2H-1,3-Benzoxazine natural products and related bioactive molecules.

4-(2-Bromo-5-chlorobenzyl)-7-chloro-2-phenyl-2H-benzo[e][1,3]oxazine 2 as a light-yellow solid (82% yield).

1H NMR (500 MHz, CDCl3): δ (ppm) 7.55–7.52 (m, 3H), 7.42–7.34 (m, 3H), 7.30 (d, 1H, J = 3.5 Hz,) 7.29 (s, 1H), 7.12 (dd, 1H, J = 8.5 Hz, 2.5 Hz), 6.95–6.91 (m, 2H), 6.57 (1H, s), 4.16 (ABq, 2H, ΔδAB = 0.05, JAB = 16.5 Hz).

13C NMR (125 MHz, CDCl3): δ (ppm) 161.5, 155.8, 139.2, 138.9, 138.1, 133.8, 133.5, 130.6, 128.8, 128.7, 128.5, 127.0, 126.3, 122.6, 121.9, 117.3, 116.2, 88.9, 40.8.

HRMS TOF MS (m/z): [M + H]+ calcd for [C21H14BrCl2NO H] 445.9709; found 445.9713.

FTIR(neat): 3060, 1633, 1596, 1454, 1364, 1344 cm–1.

Spectroscopic data for 2 were identical to those reported in the literature.(4)

Li, H.; Belyk, K. M.; Yin, J.; Chen, Q.; Hyde, A.; Ji, Y.; Oliver, S.; Tudge, M.; Campeau, L.-C.; Campos, K. R. J. Am. Chem. Soc. 2015, 137,13728– 13731 DOI: 10.1021/jacs.5b05934

Development of a General Protocol To Prepare 2H-1,3-Benzoxazine Derivatives

Ji Qi*†∥ , Steven F. Oliver‡∥, Wensong Xiao§, Licheng Song§, and Karel M. J. Brands∥

† Department of Process Research and Development, MSD R&D (China) Co., Ltd., Building 21 Rongda Road, Wangjing R&D Base, Zhongguancun Electronic Zone West Zone, Beijing 100012, China

‡ Department of Process Research and Development, Merck Sharp & Dohme, Hertford Road, Hoddesdon, Hertfordshire EN11 9BU, United Kingdom

§ Department of Synthetic Chemistry, Pharmaron Beijing Co., Ltd., 6 Taihe Road BDA, Beijing, 100176, China

∥ Department of Process Research and Development, Merck Research Laboratories, P.O. Box 2000, Rahway, New Jersey 07065, United States

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.7b00209

Publication Date (Web): August 23, 2017

Copyright © 2017 American Chemical Society

*E-mail: ji_qi@merck.com.

ACS Editors’ Choice – This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes.

Abstract

A practical synthesis and detailed development process of 2H-1,3-benzoxazine derivatives catalyzed by aldimine and trifluoromethanesulfonic acid is described. A broad range of substrates with diverse steric and electronic properties were explored. Aliphatic/aromatic/heteroaromatic substrates all proceed well under conditions which have been optimized into a robust, scalable process.

http://pubs.acs.org/doi/full/10.1021/acs.oprd.7b00209

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Photochemical intramolecular amination for the synthesis of heterocycles

Green Chem., 2017, Advance Article
DOI: 10.1039/C7GC02261A, Communication

Shawn Parisien-Collette, Corentin Cruche, Xavier Abel-Snape, Shawn K. Collins
Polycyclic heterocycles can be formed in good to excellent yields via photochemical conversion of the corresponding substituted aryl azides under irradiation with purple LEDs in a continuous flow reactor.

Photochemical intramolecular amination for the synthesis of heterocycles

 

Shawn Parisien-Collette,^a  Corentin Cruché,^a  Xavier Abel-Snape^a  and  Shawn K. Collins*^a 

 Author affiliations

*Corresponding authors

^aShawn Parisien-Collette, Corentin Cruché, Xavier Abel-Snape and Prof, Dr Shawn K. Collins, Department of Chemistry and Centre in Green Chemistry and Catalysis, Université de Montréal, CP 6128 Station Downtown, Montréal, Canada H3C 3J7
E-mail: shawn.collins@umontreal.ca

Abstract

Polycyclic heterocycles can be formed in good to excellent yields via photochemical conversion of the corresponding substituted aryl azides under irradiation with purple LEDs in a continuous flow reactor. The experimental set-up is tolerant to UV-sensitive functional groups while affording diverse carbazoles, as well as an indole and pyrrole framework, in short reaction times. The photochemical method is presumed to progress through a mechanism differing from the other methods of azide activation involving transition metal catalysis.

Methyl 9H-carbazole-2-carboxylate (9): Following the Photodecomposition Procedure A, starting from Methyl 2’-azido-[1,1’-biphenyl]-4-carboxylate, the crude mixture was purified by silica gel column chromatography (100 % hexanes → 10 % ethyl acetate in hexanes), to afford the desired product as a white solid (24.3 mg, 72 % yield). Following the Photodecomposition Procedure B, starting from Methyl 2’-azido-[1,1’- biphenyl]-4-carboxylate, the crude mixture was purified by silica gel column chromatography (100 % hexanes → 10 % ethyl acetate in hexanes), to afford the desired product as a white solid (27.7 mg, 82 % yield). NMR data was in accordance with what was previously reported.16
16 Takamatsu, K.; Hirano, K.; Satoh, T.; Miura, M. Org. Lett. 2014, 16, 2892-2895

NEXT..............

 

4-Isopropyl-9H-carbazole (14): Following the Photodecomposition Procedure A, starting from 2-azido-2’-isopropyl-1,1’-biphenyl, the crude mixture was purified by silica gel column chromatography (100 % hexanes → 10 % ethyl acetate in hexanes), to afford the desired product as a yellow solid (16.6 mg, 53 % yield). Following the Photodecomposition Procedure B, starting from 2-azido-2’-isopropyl-1,1’-biphenyl and using ethyl acetate as the solvant, the crude mixture was purified by silica gel column chromatography (100 % hexanes → 10 % ethyl acetate in hexanes), to afford the desired product as a yellow solid (16.0 mg, 51 % yield).

1H NMR (400 MHz, DMSO-d6) δ = 11.29 (s, 1H), 8.11 (d, J = 8.1 Hz, 1H), 7.50 (d, J = 8.1 Hz, 1H), 7.39-7.31 (m, 3H), 7.19- 7.15 (m, 1H), 7.08-7.03 (m, 1H), 3.92-3.82 (m, 1H), 1.41 (d, J = 6.8 Hz, 6H);

13C NMR (100 MHz, DMSO-d6) δ = 143.9, 140.3, 140.1, 126.0, 125.2, 122.8, 122.2, 119.9, 119.1, 114.9, 111.2, 108.9, 30.2, 22.8 (2C);

HRMS (ESI) m/z calculated for C15H15N [M-H]- 208.1130; found 208.1126.

///////////http://pubs.rsc.org/en/Content/ArticleLanding/2017/GC/C7GC02261A?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

Diethyl Chlorophosphate

 

 

Diethyl Chlorophosphate (CAS no 814–49–3)(15)

Preparative Procedure

In a dry four-neck 250 mL round-bottom flask equipped with a mechanical stirrer, a thermometer, and an argon inlet were introduced at 20 °C triethylamine (21.3 g, 210 mmol), tert-butyl methyl ether (75 mL), and ethanol (9.67 g, 210 mmol). Phosphorus oxychloride (15.3 g, 100 mmol) was added dropwise in 10 min via a syringe; the temperature was maintained below −5 °C. Then, the cooling bath was removed and the white suspension was vigorously stirred during 5 h at 20 °C. The mixture was filtered and the solid was rinsed with 3 × 100 mL of diethyl ether. The solvents were removed under vacuo. The resulting crudez product was distilled under reduced pressure to afford 15.4 g (89% yield) of diethyl chlorophosphate containing 3% of triethylphosphate.

Eb3 = 51 °C (lit:(3) Eb10 = 85–87 °C).

 

1H NMR (CDCl3, 300 MHz, δ): 1.37 (6H, t, J = 6.0 Hz), 4.16–4.30 (4H, m).

 

13C NMR (CDCl3, 75 MHz, δ): 15.6 (d, J = 7.5 Hz), 65.7 (d, J = 6.8 Hz).

 

 

31P RMN (CDCl3, 121 MHz, δ): 4.5.

 

15Acharya, J.; Gupta, A. K.; Shakya, P. D.; Kaushik, M. P. Tetrahedron Lett. 2005, 46, 5293 DOI: 10.1016/j.tetlet.2005.06.024

 

  

 

 

Eco-Friendly and Industrially Scalable Synthesis of the Sex Pheromone of Lobesia botrana. Important Progress for the Eco-Protection of Vineyard

Gérard Cahiez*† , Olivier Guerret‡, Alban Moyeux†§, Samuel Dufour‡, and Nicolas Lefevre†

† Chimie ParisTech, PSL Research University, CNRS, Institut de Recherche de Chimie Paris (IRCP), F-75005 Paris, France

‡ M2i, Route Nationale 117, Lotissement Induslacq, 64170 Lacq, France

§ Université Paris 13, 74 rue Marcel Cachin, 93017 Bobigny, France

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.7b00206

 

*E-mail: gerard-cahiez@chimie-paristech.fr.

http://pubs.acs.org/doi/suppl/10.1021/acs.oprd.7b00206

 

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http://www.rsc.org/suppdata/c6/nj/c6nj03712g/c6nj03712g1.pdf

Catalyst-free multi-component cascade C–H-functionalization in water using molecular oxygen: an approach to 1,3-oxazines

 

Catalyst-free multi-component cascade C-H-functionalization in water using molecular oxygen: an approach to 1,3-oxazines

Green Chem., 2017, 19,4036-4042
DOI: 10.1039/C7GC01494E, Communication

Mohit L. Deb, Choitanya D. Pegu, Paran J. Borpatra, Prakash J. Saikia, Pranjal K. Baruah
Synthesis of 1,3-oxazines via catalyst free C-H functionalization using molecular oxygen in water.

Catalyst-free multi-component cascade C–H-functionalization in water using molecular oxygen: an approach to 1,3-oxazines

Mohit L. Deb,*^a  Choitanya D. Pegu,^a  Paran J. Borpatra,^a  Prakash J. Saikia^b  and  Pranjal K. Baruah*^a 

 Author affiliations

*Corresponding authors

^aDepartment of Applied Sciences, GUIST, Gauhati University, Guwahati-781014, India
E-mail: mohitdd.deb@gmail.com, baruah.pranjal@gmail.com
Fax: +91-8876998905
Tel: +91-8876998905

^bAnalytical chemistry division, CSIR-NEIST, Jorhat-785006, India

Abstract

Herein, catalyst-free 3-component reactions of naphthols, aldehydes, and tetrahydroisoquinolines to synthesize 1,3-oxazines is reported. The reaction is performed in H₂O in the presence of O₂ as the sole oxidant at 100 °C, which proceeds through the formation of 1-aminoalkyl-2-naphthols followed by selective α-C–H functionalization of tert-amine.

15-phenyl-7a,12,13,15-tetrahydronaphtho[1',2':5,6][1,3]oxazino[2,3- a]isoquinoline (4a):1
White solid; Yield 61 %, 221 mg;
1H NMR (500 MHz, CDCl3): δ 7.79-7.77 (m, 1H), 7.74 (d, J = 8.9 Hz, 1H), 7.43-7.41 (m, 1H), 7.33-7.28 (m, 8H), 7.24-7.19 (m, 3H), 7.11 (d, J = 8.9 Hz, 1H), 5.65 (s, 1H), 5.44 (s, 1H), 3.40-3.26 (m, 2H), 3.12-3.09 (m, 1H), 2.90- 2.86 (m, 1H);
13C NMR (125 MHz, CDCl3): δ 151.9, 142.3, 135.0, 133.0, 132.4, 129.3, 129.1, 128.9, 128.8 (2C), 128.7, 128.6, 128.2, 127.4, 126.5, 126.2, 123.1, 122.7, 118.9, 110.9, 82.2, 62.6, 45.4, 29.4;
HRMS (ESI) exact mass calculated for C26H21NO [M+H]+ : 364.1701; found: 364.1705.
The representative procedure for the synthesis of 4a is as follows: 2-naphthol (1a, 144 mg, 1 mmol), benzaldehyde (2a, 106 mg, 1 mmol), tetrahydroisoquinoline (3, 133 mg, 1 mmol) and water (1.5 mL) were added in a round-bottom flask equipped with a magnetic stirring bar and a reflux condenser. The whole apparatus was efficiently flushed with oxygen gas and then connected to a balloon filled with oxygen. After vigorous stirring at 100 oC for 12 h, water was removed under vacuum and purified the reaction mixture by column chromatography (100-200 mesh silica gel, hexane-ethyl acetate) to obtain the product 4a as white solid. The other 1,3-oxazines were synthesized and purified by following the procedure described above

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2,5-Diformylfuran an easy molecule to learn NMR

2,5-Diformylfuran (DFF), 5 (lit. 2 ) 2 Kashparova, V. P., Khokhlova, E. A., Galkin, K. I., Chernyshev, V. M. & Ananikov, V. P. The “onepot” synthesis of 2,5-diformylfuran, a promising synthon for organic materials in the conversion of biomass. Russ. Chem. Bull. 64, 1069-1073 (2015).

1H NMR (CDCl3) = 9.87 (s, 2H), 7.35 (s, 2H);

13C NMR (CDCl3) = 181.1, 154.1, 122.5 ppm.

PREDICT

Efficient route for the construction of polycyclic systems from bioderived HMF 

Green Chem., 2017, Advance Article
DOI: 10.1039/C7GC02211E, Paper

F. A. Kucherov, K. I. Galkin, E. G. Gordeev, V. P. Ananikov
Efficient one-pot synthesis of tricyclic compounds from biobased 5-hydroxymethylfurfural (HMF) is described using a [4 + 2] cycloaddition reaction.

Efficient route for the construction of polycyclic systems from bioderived HMF

F. A. Kucherov,^a  K. I. Galkin,^a  E. G. Gordeev^a  and  V. P. Ananikov*^a 

 Author affiliations

*Corresponding authors

^aZelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky pr. 47, Moscow 119991, Russia
E-mail: val@ioc.ac.ru
Web: http://AnanikovLab.ru

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