DR ANTHONY MELVIN CRASTO,WorldDrugTracker, helping millions, A 90 % paralysed man in action for you, I am suffering from transverse mylitis and bound to a wheel chair, With death on the horizon, nothing will not stop me except God................DR ANTHONY MELVIN CRASTO Ph.D ( ICT, Mumbai) , INDIA 25Yrs Exp. in the feld of Organic Chemistry,Working for GLENMARK GENERICS at Navi Mumbai, INDIA. Serving chemists around the world. Helping them with websites on Chemistry.Million hits on google, world acclamation from industry, academia, drug authorities for websites, blogs and educational contribution

Thursday, 30 March 2017

3-allyl-4H-chromen-4-one

str1
3-allyl-4H-chromen-4-one
5b (8.4 g, 45 mmol, 91% yield) as a yellow oil. GC (retention time): 3.571 min
HRMS (EI): m/z calcd for [C12H10O2]: 186,0681 (M+ ); found 186.0657.
1H-NMR (400 MHz, CDCl3 ): δ/ppm = 8.18 (dd, J=8.0, 1.7 Hz, 1H), 7.70 (t, J=1.0, 1H), 7.58 (ddd, J=8.6, 7.1, 1.7 Hz, 1H), 7.43 – 7.28 (m, 2H), 5.92 (ddt, J=16.7, 10.1, 6.7 Hz, 1H), 5.22 – 5.04 (m, 2H), 3.20 (dt, J=6.7, 1.3, 2H).
13C NMR (75 MHz, CDCl3 ): δ/ppm = 177.5, 156.6, 152.7, 134.7, 133.5, 126.0, 125.0, 123.9, 123.1, 118.1, 117.2, 29.8.
IR (Diamond-ATR, neat): /cm-1 = 3077.00 (w), 3068.00 (w), 3017.00 (vw), 2970.00 (w), 2941.00 (vw), 2900.00 (w), 1632.00 (s), 1608.00 (s), 1573.00 (m), 1464.00 (s), 1429.00 (m), 1398.00 (s), 1353.00 (s), 1321.00 (m), 1297.00 (m), 1282.00 (m), 1264.00 (w), 1226.00 (w), 1210.00 (m), 1181.00 (m), 1156.00 (s), 1141.00 (s), 1111.00 (m), 1027.00 (w), 1005.00 (m), 961.00 (m), 924.00 (s), 909.00 (s), 896.00 (s), 868.00 (w), 846.00 (s), 802.00 (m), 769.00 (s), 756.00 (vs), 712.00 (m), 690.00 (s).
mp: 34.0 - 36.0 °C

Practical Large-Scale Regioselective Zincation of Chromone Using TMPZnCl·LiCl Triggered by the Presence or Absence of MgCl2

 Department Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse. 5-13, 81377 München, Germany
 Research & Development, Crop Science, Bayer AG, Alfred-Nobel-Strasse 50, Building 6550, 2.08, 40789 Monheim am Rhein, Germany
Org. Process Res. Dev., Article ASAP
DOI: 10.1021/acs.oprd.7b00032
Abstract Image
Chromones are efficiently zincated in position C(3) in THF by using the commercially available amide base TMPZnCl·LiCl (TMP = 2,2,6,6-tetramethylpiperidyl). Additionally, in the presence of a Lewis acid such as MgCl2, zincation using TMPZnCl·LiCl occurs at C(2). These metalation reactions are carried out on a 50 mmol scale, and the metalation selectivities have been compared with the corresponding small-scale reactions (2 mmol). The resulting zinc organometallics undergo smooth reactions with various electrophiles, for example, Pd-catalyzed cross-coupling reactions or Cu-catalyzed acylations or allylations.