HMBC Described for (Z)-2-Isopropylimino-3-phenyl-thiazolidin-4-one

(Z)-2-Isopropylimino-3-phenyl-thiazolidin-4-one (3a)

3a as an off-white crystalline solid (4.60 g, 88%), mp 149 °C.

¹H NMR (CDCl₃): δ 1.14 (d, J = 6.3 Hz, 6 H, H2b), 3.52 (hept, J = 6.0 Hz, 1 H, H2a), 3.98 (s, 2 H, H5), 7.27−7.32 (m, 2 H, H3b), 7.37−7.44 (m, 1 H, H3d), 7.45−7.52 (m, 2 H, H3c).

¹³C NMR (CDCl₃): δ 23.35 (C2b), 32.58 (C5), 53.86 (C2a), 128.03 (C3b), 128.41 (C3d), 128.97 (C3c), 135.30 (C3a), 149.30 (C2), 171.39 (C4).

HMBC (CDCl₃): H2a → C2, C2b; H2b → C2, C2a; H3b → C3a, C3d; H3c → C3a, C3d; H3d → C3a, C3b; H5 → C2, C4. LC-LC-MS (ES⁺): t_R0.59 min. m/z: 235 (M + H).

The organic extract containing crude (Z)-3-isopropyl-2-phenylimino-thiazolidin-4-one (4a) was concentrated and the crude byproduct was purified by column chromatography on silica gel eluting with heptane:ethyl acetate 3:1 to give pure 4a as a pale-yellow oil (278 mg, 5%).

¹H NMR (CDCl₃): δ 1.55 (d, J = 7.0 Hz, 6 H, H3b), 3.75 (s, 2 H, H5), 4.90 (hept, J = 6.8 Hz, 1 H, H3a), 6.97 (d, J = 7.5 Hz, 2 H, H2b), 7.16 (t, J = 7.5 Hz, 1 H, H2d), 7.37 (t, J = 7.5 Hz, 2 H, H2c).

¹³C NMR (CDCl₃): δ 18.72 (C3b), 32.50 (C5), 48.04 (C3a), 120.92 (C2c), 124.48 (C2d), 129.10 (C2b), 148.36 (C2a), 154.14 (C2), 171.92 (C4).

HMBC (CDCl₃): H2b → C2a, C2c, C2d; H2c → C2a, C2b, C2d; H2d → C2b, C2c; H3a → C2, C3b, C4; H3b → C3a; H5 → C2, C4. LC-MS (ES⁺): t_R 0.98 min. m/z: 235 (M + H)

(Z)-2-Propylimino-3-phenyl-thiazolidin-4-one (5a) (Method B)

To a solution of phenylisothiocyanate (2.00 g, 14.8 mmol) in dichloromethane (20 mL), n-propylamine (875 mg, 1.23 mL, 14.8 mmol) was added portionwise at 20 °C. The solution was stirred at 20 °C for 15 min. The solution was cooled to 0 °C before bromo-acetyl bromide (2.99 g, 1.29 mL, 14.8 mmol) was added carefully such that the temperature did not rise above 5 °C. The reaction mixture was stirred at 0 °C for 15 min before pyridine (2.40 g, 2.45 mL, 30.3 mmol) was added at 0 °C. The mixture was stirred for another 15 min at 0 °C, then warmed to 20 °C and washed with water (10 mL). The aqueous layer is extracted with dichloromethane (10 mL). The solvent of combined organic extracts was evaporated under reduced pressure to afford 5a(1.84 g, 53%) as an off-white solid, mp 138 °C. This material was sufficiently pure (>90%) for further use in the subsequent condensation step with substituted benzaldehydes. ¹H NMR (CDCl₃): δ 0.92 (t, J = 7.3 Hz, 2 H, H2c), 1.61 (h, J = 7.0 Hz, 2 H, H2b), 3.28 (t, J = 7.0 Hz, 2 H, H2a), 4.00 (s, 2 H, H5), 7.28−7.32 (m, 2 H, H3b), 7.37−7.45 (m, 1 H, H3d), 7.47−7.53 (m, 2 H, H3c). ¹³C NMR (CDCl₃): δ 11.86 (C2c), 23.57 (C2b), 32.56 (C5), 54.29 (C2a), 127.98 (C3b), 128.63 (C3d), 129.17 (C3c), 135.17 (C3a), 151.67 (C2), 171.37 (C4). HMBC (CDCl₃): H2a → C2, C2b, C2c; H2b → C2a, C2c; H2c → C2a, C2b; H3b → C3a, C3d; H3c → C3a, C3b; H3d → C3a, C3b; H5 → C2, C4. LC-MS (ES⁺): t_R 0.60 min. m/z: 235 (M + H)

J. Med. Chem., 2010, 53 (10), pp 4198–4211

DOI: 10.1021/jm100181s

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Cape Maclear, Malawi

With no brine, sharks or jellyfish to be afraid of, this water is simply perfect for diving, snorkelling, kayaking. Peached by the edge of the massive Lake Malawi which feels like an ocean, Cape Maclear forms part of a UNESCO World Heritage Site and the beach is simply the hippie hangout. .

Cape Maclear

Town in Malawi

Cape Maclear or Chembe is a town in the Mangochi District of Malawi's Southern Region. The town, situated on the Nankumba Peninsula, is on the southern shore of Lake Malawi and is the busiest resort on Lake Malawi. Wikipedia

 

 

 

 

 


 

 

 

 

 
 

 
 
 

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