(3,4,5,6-tetrahydro-lH-thieno[3,4-c]pyrrole 2,2- dioxide hydrobromide

(3,4,5,6-tetrahydro-lH-thieno[3,4-c]pyrrole 2,2- dioxide hydrobromide; (2b)
 


Synthesis of substituent R² (3,4,5,6-tetrahydro-lH-thieno[3,4-c]pyrrole 2,2- dioxide hydrobromide; (2b) was carried out as shown in Scheme-4 and the stepwise procedure is depicted below:
Scheme-4:

Bz-NH

Substitued R² (2b)
Step-1 : 2,3-dimethylbuta-L3-diene (14)
To 2,3-dimethylbutane-2,3-diol (13, 85g), 48% aqueous HBr was added to get the colorless solution. Mixture was fractionally distilled, washed twice with water and dried over anhydrous CaCl₂. Mixture was redistilled and the fraction of 69-70 °C was collected to get 2,3-dimethylbuta-l,3-diene (14, 38g. 64%yield). 1H NMR: (CDCl₃, 400 MHz): δ 5.06 (2H, s), 4.97 (2H, s), 1.92 (6H, s); ESI-MS: (+ve mode) 83.3 (M+H)⁺ (70 %).


Step-2: 3,4-dimethyl-2,5-dihydrothiophene 1,1 -dioxide (15)
A mixture of hydroquinone (492mg) and 2,3-dimethylbuta-l ,3-diene (14, 31.96 ml) was placed in sealed tube and a solution of sulfur dioxide in MeOH (140 ml) was added. Reaction mixture was heated at 85 °C for 4 h and cooled to room temperature. Crystals obtained was filtered, washed with cold methanol and dried to get 3,4- dimethyl-2,5-dihydrothiophene 1,1 -dioxide (15) as white crystalline solid (30 gm, 72% yield).
lH NMR: (CDCl_3, 400 MHz): δ 3.73 (4H, d, J = 1.2 Hz), 1.78 (6H, t, J = 1.2 Hz); ESI- MS: (+ve mode) 147.2 (M+H)⁺ (70 %), 169.1 (M+Na)⁺ (40%).


Step-3: 3,4-bis(bromomethyl)-2,5-dihydrothiophene 1,1 -dioxide (16)
A mixture of 3,4-dimethyl-2,5-dihydrothiophene 1,1-dioxide (15, 20g), 1- bromopyrrolidine-2,5-dione (53.5g), and AIBN (400mg) in CHC1₃ was heated for 15 hr. After completion of reaction, filtrate was evaporated under reduced pressure. The residue obtained was recrystallize from methanol to get 3,4-bis(bromomethyl)-2,5- dihydrothiophene 1,1-dioxide as a white crystals (16, 19 g, 45% yield).
1H NMR: (CDC1_3> 400 MHz): δ 4.06 (4H, s), 4.01 (4H, s); ESI-MS: (+ve mode) 303.8 (M+H)⁺ (90 %), 305.7 (M+2H)⁺ (70%).


Step-4: 5-benzyl-3,4,5,6-tetrahydro-lH-thieno[3,4-c]pyrrole 2,2-dioxide (17)
Mixture of 3,4-bis(bromomethyl)-2,5-dihydrothiophene 1,1-dioxide (16, 12g) and phenylmethanamine (10.84ml) in acetonitrile was stirred at 25 °C for 2 hr. After completion of reaction, solvent was removed under reduced pressure, ethyl acetate and IN NaOH were added, organic layer was separated and aq layer was extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous Na₂S0₄ and concentrated under reduced pressure to give 5-benzyI-3,4,5,6-tetrahydro- lH-thieno[3,4-c]pyrrole 2,2-dioxide (17) as a solid compound (3.7 g, 38% yield).
1H NMR: (CDCI_3, 400 MHz): δ 7.34-7.29 (5H, m), 3.88 (2H, s), 3.77 (4H,s), 3.61 (4H, s); ESI-MS: (+ve mode) 250.3 (M+H)⁺ (100 %).

Step-5: benzyl 4,6-dihvdro-lH-thieno[3,4-clpyrrole-5(3H^")-carboxylate 2,2-dioxide (IS) A mixture of 5-benzyl-3,4,5,6-tetrahydro-lH-thieno[3,4-c]pyrrole 2,2-dioxide (17, 3.6g) and CBZ-C1 (13.5 ml) in toluene was stirred for 3 hr. After completion of reaction, diethyl ether was added till solid precipitated out. Solid was filtered and dried under reduced pressure to get benzyl 4,6-dihydro-lH-thieno[3,4-c]pyrrole-5(3H)- carboxylate 2,2-dioxide (18, 2.7 g, 64% yield). ^lH NMR: (CDC1_3, 400 MHz): δ 7.38-7.35 (5H, m), 5.19 (2H, s), 4.31 (4H, s), 3.88 (4H, d, J = 13.6 Hz); ESI-MS: (+ve mode) 294.4 (M+H)⁺ (80 %).


Step-6: 3 A5,6-tetrahydro-lH-thieno[3,4-c]pyrrole 2,2-dioxide hydrobromide (2b)
To a solution of benzyl 4,6-dihydro-lH-thieno[3,4-c]pyrrole-5(3H)-carboxylate 2,2-dioxide (18, 3.7 g) in glacial acetic acid, HBr in glacial acetic acid was added and the reaction mixture was stirred at 2 °C for 3h. After completion of reaction, diethyl ether was added to afford sticky solid, solvent was decanted and added minimum amount of methanol to get the crystalline solid as 3,4,5,6-tetrahydro-lH-thieno[3,4- c]pyrrole 2,2-dioxide hydrobromide as a hydrobromide salt (2b, 1.5 g, 50% yield). 1H NMR: (CDCI₃, 400 MHz): δ 9.43 (2H, bs), 4.08 (4H, s), 4.02 (4H, s); ESI-MS: (+ve mode) 160.4 (M+H)⁺ (88 %).


/////WO2014061031

3-(4,4,5,5-Tetramethyl-[1,3,2]dioxaborolan-2-yl)pyridine.

5.........3-pyridylboronic acid pinacol ester
 3-(4,4,5,5-Tetramethyl-[1,3,2]dioxaborolan-2-yl)pyridine.
 Pyridine, 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-; (329214-79-1)

compd5=  obtained the product in 74-82% yield in different runs. The product exhibits the following physical properties: mp 102-105°C; IR (KBr pellet) cm⁻¹ 2994, 2968, 2932, 1609, 1572, 1476, 1410, 1361, 1209, 1154, 1063, 1017, 953, 926, 859, 833, 800, 759, 705; ¹H NMR pdf (500 MHz, CDCl₃): δ 1.33 (s, 12H), 7.25 (ddd, J=1.1, 4.9, 7.5, 1H), 8.03 (dt, J=1.8, 7.5, 1H), 8.64 (dd, J=1.9, 4.9, 1H), 8.93 (d, J=1.1, 1H); ¹³C NMR (126 MHz, CDCl₃) δ 24.8, 84.1, 123.0, 142.2, 152.0, 155.5; MS (EI, 70 eV): 205 (M+, 46), 204 (15), 191 (12), 190 (100), 189 (25), 162 (10), 148 (44), 147 (14), 120 (18), 119 (11), 106 (100), 105 (35), 85 (15), 59 (17), 58 (19); HRMS (EI) m/z 205.1280, calcd for C₁₁H₁₆NO₂B 205.1274. Anal. Calcd for : C₁₁H₁₆BO₂N: C, 64.43; H, 7.86; N, 6.83. Found: C, 64.23; H, 7.99; N, 6.88.

An Improved Protocol for the Preparation of 3-Pyridyl- and Some Arylboronic Acids

Wenjie Li ,* Dorian P. Nelson ,* Mark S. Jensen , R. Scott Hoerrner , Dongwei Cai , Robert D. Larsen , and Paul J. Reider

Process Research Department, Merck Research Laboratories, P.O. Box 2000, Rahway, New Jersey 07065 wenjie_li@merck.com; dorian_nelson@merck.com

J. Org. Chem., 2002, 67 (15), pp 5394–5397

DOI: 10.1021/jo025792p

Publication Date (Web): June 13, 2002

Copyright © 2002 American Chemical Society

Abstract

3-Pyridylboronic acid was prepared in high yield and bulk quantity from 3-bromopyridine via a protocol of lithium−halogen exchange and “in situ quench”. This technique was further studied and evaluated on other aryl halides in the preparation of arylboronic acids. 

 paper

 http://www.orgsyn.org/demo.aspx?prep=v81p0089

 .


 


Tunis, tunisia
.



 

 
 
 



 

 
 With Tarek Chelsea at Av. de la Liberté - Lafayette Tunis.


 

 
 Past... — at Carthage Land.

 

 

 

 
 


 

 

 
 

 
  Wisem Djerbien at Hay ennasr tunis.

 
 
 

 
 

 
 

 

 

 

 
 
 

 
 
 

 Les Berges du Lac, Tunis, Tunisia

 

 Alstom low-floor trolley, Place de Barcelona, Tunis, Tunisia

 

 Tunis-Carthage International Airport, Tunisia

 

 Republique Station, Metro leger, Tunis, Tunisia

 

 People walk through the town's main avenue, Avenue Habib Bourguiba.

 

 

 




////////////////

5-fluoro-2- (4,4,5,5, - tetramethyl-1,3,2-dioxaborolan-2-yl) benzaldehyde

 

5-fluoro-2- (4,4,5,5, - tetramethyl-1,3,2-dioxaborolan-2-yl) benzaldehyde

SYNTHESIS 94)

2-bromo-5-fluorobenzaldehyde 26.1g (129mmol), 4,4,4 ', 4', 5,5,5 ', 5'- octamethyl-2,2'-bi-1,3,2- dioxaborolane 39.2g (154mmol), N of potassium acetate 25.2g (257mmol) and [1,1'-bis (diphenylphosphino) ferrocene] dichloro palladium (II) dichloromethane adduct 5.25g (6.43mmol), It was stirred for 16 hours at 100 ℃ the N- dimethylformamide (200mL) solution.Water was added to the reaction mixture and extracted with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, the crude product obtained was concentrated and purified by silica gel chromatography (5% -25% ethyl acetate / hexanes), the title compound 16.6g of (52%) pale yellow crystals It was obtained as a. ¹ H-NMR (300MHz, CDCl₃₎ ^δ1.38 (12H, s), 7.27 (1H, td, J = 2.7,8.1Hz), 7.65 (1H, dd, J = 2. 7,9.3Hz), 7.92 (1H, dd, J = 6.3,8.1Hz), 10.62 (1H, d, J = 3.3Hz), melting point 55-58 ℃. Starting materials

2-Bromo-5-fluorobenzaldehyde

• CAS Number 94569-84-3

 

Bis(pinacolato)diboron

4,4,4',4',5,5,5',5'-octamethyl-2,2'-Bi-(1,3,2-dioxaborolane

Identifiers
CAS Registry Number	73183-34-3
Jmol-3D images	Image
PubChem	2733548
Properties
Chemical formula	C12H24B2O4
Molar mass	253.94 g·mol−1
Melting point	137 to 140 °C (279 to 284 °F; 410 to 413 K)

  Bis(pinacolato)diboron is a boron containing two pinacolato ligands. With the formula [(CH₃)₄C₂O₂B]₂, it is a colourless solid that is soluble in organic solvents. It is a commercially available reagent for making pinacol boronic esters for organic synthesis.

Preparation and structure

This compound may be prepared by reacting tetrakis(dimethylamino)diboron with pinacol in acidic conditions.^[1] The B-B bond distance is 1.711(6) Å.^[2]

References

1. Tatsuo Ishiyama, Miki Murata, Taka-aki Ahiko, and Norio Miyaura (2004). "Bis(pinacolato)diboron". Org. Synth.; Coll. Vol. 10, p. 115
2. C.Kleeberg, A.G.Crawford, A.S.Batsanov, P.Hodgkinson, D.C.Apperley, Man Sing Cheung, Zhenyang Lin, T.B.Marder "Spectroscopic and Structural Characterization of the CyNHC Adduct of B₂pin₂ in Solution and in the Solid State" J. Org. Chem 2012, vol. 77, pp. 785.doi:10.1021/jo202127c
3. Xinyu Liu "Bis(pinacolato)diboron" Synlett 2003, pp 2442–2443. doi:10.1055/s-2003-43344
4. http://www.google.fr/patents/WO2010110400A1?cl=en&hl=fr

 GOA, INDIA



 
 


 

 

 

 
 
 Tollecanto Velim Goa.

 

 
 

 
 

 

 
 

 
 

 

 
 

 

 List Of Pharmaceutical Companies In GOA @ http://pharmatips.doyouknow.in/Articles/Pharma-Companies/List-Of-Pharmaceutical-Companies-In-GOA.aspx
 


 

 

 






////////////5-fluoro-2- (4,4,5,5, - tetramethyl-1,3,2-dioxaborolan-2-yl) benzaldehyde