2023_BG_5A_2 - Thiourea formation on 2-amino-5-nitropyridine

[KlementineJBS]

Reaction scheme

Outcome

[KlementineJBS]

1. Dissolved KSCN (3.217 g, 33.0 mmol, 1.2 eqiuv.) in acetone (150 mL)
2. Stirred and began heating to 60 C
3. Added benzoyl chloride (3.5 mL, 30.14 mmol, 1.1 equiv.)
4. Left stirring at 60 C from 11.10
5. Added amine (3.82 g, 27.4 mmol) at 11.40 by solution transfer with 20 mL acetone
6. Left stirring and heating
7. took off around 2 pm and performed usual workup (precipitation into ice water, vacuum filter, wash with water and isopropanol)

vial: 15.7428 full vial: 17.6117 mass: 1.8869 g (6.24 mmol, 23%)

[KlementineJBS]

8. Extracted aqueous extract with ethyl acetate (3 x 125 mL). third extract went pink and was collected and dried separately.
9. washed with brine (150 mL)
10. dried over mag sulphate and rotovapped down - difficult to rotovap as too much product made it bump repeatedly. upon rotovapping, the purple-pink extract turned into a bright orange-yellow solid

First extraction

Third extraction

vial (3rd extract): 15.9523 full vial: 16.4832 mass: 530.9 mg (1.76 mmol, 6%)

beaker: 28.2324 full beaker:

[KlementineJBS]

H NMR

NMR of precipitate and 3rd extract did not match. Need to analyse further.

2023_BG_5A_2.pdf 2023_BG_5A_2 3rd extract_1.zip 2023_BG_5A_2_1.zip

[KlementineJBS]

LRMS

Signs of product in both.

301.01 [M-H]-, 625.11 [2M+Na]-. 2023_BG_5A_2.pdf

301.02 [M-H]-. Unidentified positive peaks at 230.14, 248.11, 437.13, 473.10. 2023_BG_5A_2 extract.pdf