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

Tuesday 29 January 2019

A solvent-free catalytic protocol for the Achmatowicz rearrangement

Graphical abstract: A solvent-free catalytic protocol for the Achmatowicz rearrangement

Abstract

Reported here is the development of an environmentally friendly catalytic (KBr/oxone) and solvent-free protocol for the Achmatowicz rearrangement (AchR). Different from all previous methods is that the use of chromatographic alumina (Al2O3) allows AchR to proceed smoothly in the absence of any organic solvent and therefore considerably facilitates the subsequent workup and purification with minimal environmental impacts. Importantly, this protocol allows for scaling up (from milligram to gram), recycling of the Al2O3, and integrating with other reactions in a one-pot sequential manner.

A solvent-free catalytic protocol for the

Achmatowicz rearrangement

 
 Author affiliations
1n: colorless oil, 0.33 g, 73% yield for 2 steps.
1H-NMR (400 MHz, DMSO) δ: 7.59–7.58 (m, 1H), 7.45 (s, 2H), 6.40 (dd, J = 3.2, 1.8 Hz, 1H), 6.29 (d, J = 3.2 Hz, 1H), 5.49 (s, 1H), 4.74–4.60 (m, 1H), 4.18–4.07 (m, 2H), 2.09–2.04 (m, 2H).
13C-NMR (100 MHz, DMSO) δ: 157.6, 142.4, 110.7, 106.1, 66.5, 62.8, 35.2. IR (KBr) 3282.9, 2928.7, 1627.4, 1562.5, 1353.8, 1174.6, 1074.0, 999.7, 918.4, 742.8 cm-1 ;
HRMS (CI+ ) (m/z) calcd. for C7H11NO5S [M]+ 221.0352; found 221.0354.
STR1 STR2 str3



2n (EtOAc/hexane = 3:1):colorless oil (dr 7:3), 46 mg, 97%.
1H-NMR (400 MHz, DMSO) δ: 7.48–7.47 (m, 2H), 7.34–7.02 (m, 2H), 6.12–6.03 (m, 1H), 5.61–5.48 (m, 1H), 4.60 (dd, J = 8.3, 4.1 Hz, 0.7H), 4.28 (ddd, J = 8.8, 4.0, 1.3 Hz, 0.3H), 4.20–4.11 (m, 2H), 2.27–2.20 (m, 1H), 1.97–1.86 (m, 1H).
13C-NMR (100 MHz, DMSO) δ: 196.7, 196.5, 151.9, 148.3, 127.7, 126.0, 90.9, 87.2, 74.6, 70.1, 65.8, 65.8, 30.3, 29.6. IR (KBr) 3370.4, 2987.0, 1689.5, 1364.3, 1268.0, 1178.4, 1023.3, 928.3, 755.1 cm-1 ;
HRMS (CI+ ) (m/z) calcd. for C7H11NO6S [M]+ 237.0302; found 237.0315.
STR1 STR2
////////////////Achmatowicz rearrangement

1 comment:

  1. Great post. This article is really very interesting and enjoyable. I think its must be helpful and informative for us. Thanks for sharing your nice post about Computer-Aided Drug Design. We are also post the same read about Career In Computer-Aided Drug Design

    Thanks for this and keep sharing..!!!

    ReplyDelete