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1st February 2012 @ 06:40
Synthesis of acetonitrile substituted p-trifluoromethyl near neighbour analogue (ZYH 10-2)

reactionscheme10-2-2.jpg

Experiment start time: 15:00 EST 01/02/2012
Potassium carbonate (313 mg), sodium iodide (280 mg) and ZYH 6-2 were stirred in acetonitrile and bromoacetonitrile (0.09 mL) was added. The mixture was heated to 80 °C. TLC after 2 hours showed the formation of product, but the reaction was incomplete and the mixture was allowed to cool and left overnight. TLC in the morning showed disappearance of product and the mixture was extracted with ethyl acetate (40 mL) and washed with water (3 x 20 mL) and brine (20 mL) and concentrated under reduced pressure to give a brown gum, which showed two spots by TLC corresponding with two different products, each with a nearby shadow spot. The gum was purified by column chromatography (20-50% ethyl acetate in hexane on silica)to give two pure fractions and and a mixed fraction containing the first fraction and an impurity. The eluent fractions were concentrated under reduced pressure to afford ZYH 10-2A as a greenish-brown solid (133 mg, 24%) and ZYH 10-2B as a yellow-brown solid (243 mg, 45%).

Data summary table:
Yield % Melting point °C 1H NMR 13C NMR19F NMR IR Mass spec
ZYH 10-2A 24 182-183Not assigned (.pdf) Not assigned (.pdf)Yes (pdf)Yes (pdf, .dx) ESI 982 2M+Na (pdf, .raw)
ZYH 10-2B 45 72-74Consistent (.pdf) Consistent (.pdf, multiplets)Yes (pdf)Yes (pdf, .dx) ESI 503 M+Na (pdf, .raw)


Comparison with literature:
No reference to either product was found in the literature.

High resolution mass spectrometry:
10-A: HRMS (ESI (+)) Calcd. for [C25H19F3 N4OSNa+]: 503.1124, found: 503.1126.
10-B: HRMS (ESI (+)) Calcd. for [C25H19F3 N4OSNa+]: 503.1124, found: 503.1130.

NMR spectrum assignment:
10-B: 1H NMR CDCl3, 500 MHz): δ = 1.96 (s, 3H), 2.15 (s, 3H), 5.03 (s, 2H), 6.00 (s, 1H), 7.31 (d, J = 8.3 Hz, 2H), 7.50-7.52 (m, 2H), 7.61-7.62 (m, 3H), 7.77 (d, J = 8.3 Hz, 2H), 7.84 (s, 1H). 13C NMR (CDCl3, 500 MHz): δ = 11.2 (1C), 12.8 (1C), 40.9 (1C), 105.8 (1C), 114.4 (1C), 116.4 (1C), 122.1 (1C), 123.7 (q, J = 272.5 Hz, 1C), 126.8 (q, J = 3.6, 2C), 127.9 (1C), 128.0 (2C), 128.5 (2C), 130.74 (2C), 130.76 (1C), 131.0 (q, J = 33.0 Hz, 1C), 131.4 (1C), 135.6 (1C), 139.4 (1C), 140.7 (q, J = 1.4 Hz, 2C), 177.8 (1C), 181.0 (1C) ppm.

TLC (20% ethyl acetate in hexane) visualised using UV and Vanillin:
TLC at 1 hr 30 min

Left spot: starting materials; middle spot: starting materials plus reaction mixture; right spot, reaction mixture.

X-ray crystallography:
Single crystal X-ray of 10-2A showed attachment of the acetonitrile group to the ring nitrogen of the thiazolidinone (.docx, .cif).

ZYH_10-2A.gif

Crystals of 10-2A:
10-2A_crystals.jpg
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Attached Files
1st February 2012 @ 06:24
Synthesis of cyclopentane substituted thiazolidinone from PMY 13-1

reactionscheme25-1.jpg

Experiment start time: 11:00 EST 01/02/2012
Potassium carbonate (2.2 g, 2 equiv.), sodium iodide (2.5 g, 2.2 equiv.) and PMY 13-1 (1.5 g, 1 equiv.) were stirred in acetonitrile at room temperature. Cyclopentylbromide (0.92 mL) was then added dropwise and the mixture was heated to 80 °C. TLC after 5.5 hours showed formation of a single product but the reaction was not complete and the mixture was cooled and left overnight. In the morning two product spots could be seen but the reaction was incomplete so the mixture was heated again and left at 80 °C. After 24 hours the reaction was still incomplete with two product spots, and the mixture was removed from the heat and extracted with ethyl acetate (50 mL) and washed with water (3 x 20 mL) and brine (20 mL). The organic extract was concentrated under reduced pressure and TLC showed the presence of starting material and two product spots. The mixture was adsorbed onto silica and purified by column chromatography (15-20% ethyl acetate in hexane on silica) to give a pure fraction, ZYH 25-1A, and a mixed fraction, ZYH 25-1B. Proton NMR of fraction B did not appear consistent with the desired product and fraction B and the mixed fraction were discarded.

Data summary table:
Yield Melting point 1H NMR 13C NMR19F NMR IR Mass spec
25-1 ? NeedYes (pdf, H + C NMR .zip) Yes(pdf)NAYes (pdf, .dx) Need
Attached Files
30th January 2012 @ 10:39
Condensation of PMY 13-1 and propionaldehyde (ZYH 24-1)

reactionscheme24-1.jpg

Experiment start time: 10:50 EST 30/01/2012
PMY 13-1 was dissolved in ethanol (15 mL) and propionaldehyde was added dropwise. The mixture was heated to 60 °C and turned a darker orange-brown colour but no precipitate was observed. After four hours the reaction was complete by TLC and was cooled to room temperature but the products remained in solution. After evaporating the ethanol off under reduced pressure, the orange-brown oil was dissolved in ethyl acetate and washed with water (3 x 10 mL) and brine (15 mL). The organic layer was then dried over magnesium sulfate and evaporated under reduced pressure to give a brownish-orange solid powder. After an hour or so of exposure to air the solid became tacky, suggesting ready absorption of moisture from the air. The solid was dried again under high vacuum and placed in a sealed container in the fridge. TLC and H NMR suggested a mixture of products and the experiment was put aside for the present.

High resolution mass spectrometry:
HRMS (ESI (+)) Calcd. for [C12H12N2OSH+]: 233.0743, found: 233.0736.

TLC (10% methanol in dichloromethane) visualised using UV and vanillin:
TLC at 4 hrs


Hazard and risk assessment:
Refer to: Synthesis of phenyliminothiazolidinone-substituted arylpyrrole (ZYH 3-1)
Attached Files
30th January 2012 @ 10:20
Condensation of benzaldehyde and PMY 13-1

reactionscheme23-1.jpg

Experiment start time: 10:10 EST 30/01/2012
PMY 13-1 was dissolved in ethanol (15 mL) and benzaldehyde was added dropwise. The mixture was heated to 60 °C. A yellow precipitate was first observed after half an hour and the reaction was complete by TLC after four hours. The mixture was cooled to room temperature and the precipitate was filtered off to give a very fine, brownish-yellow powder (170 mg, 51% yield).

Data summary table:
Yield % Melting point °C 1H NMR 13C NMR19F NMR IR Mass spec
ZYH 23-1 51 260-261Yes (1H + 13C NMR pdf, can't find data file) Not assignedNAYes (pdf, .dx) ESI 303 M+Na; 583 2M+Na (.raw)


Comparison with literature
The product is a known compound (CAS: 38771-64-1 or 851429-54-4 or 1082659-12-8, depending on stereochemistry) with IR, mass and H NMR spectra available for the record with the E/Z isomerism of the phenyl substitution uncharacterised.

TLC (10% methanol and dichlormethane) visualised using UV and vanillin:
TLC at 4 hrs


Hazard and risk assessment:
Refer to: Synthesis of phenyliminothiazolidinone-substituted arylpyrrole (ZYH 3-1)
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25th January 2012 @ 06:53
Arylpyrroles:
ZYH 1 product
ZYH 8 product
ZYH 9 product

Blog entries: ZYH 1-1; ZYH 8-1, ZYH 9-1

Aldehydes:
ZYH 2 product
ZYH 4 product
ZYH 11 product
ZYH 13 product

Blog entries: ZYH 2-1, 2-2; ZYH 4-1, 4-2, 4-3; ZYH 11-1; ZYH 13-1

Near neighbours:
ZYH 3 product
ZYH 5 product
ZYH 6 product
ZYH 7 product
ZYH 10 product
ZYH 12 product
ZYH 15 product
ZYH 18 product
ZYH 19 product
ZYH 17 product
ZYH 22 product

Blog entries: ZYH 3-1, ZYH 5-1, ZYH 6-1, ZYH 7-1, 7-2, ZYH 10-1, ZYH 12-1, 12-2, ZYH 15-1, ZYH 17-1, ZYH 18-1, ZYH 19-1

Modified thiazolidinone:
ZYH 23 product


Thiazolidinone precursor:
ZYH 20 product

Blog entries: ZYH 20-1
Attached Files