KBS34-1 - Synthesis of methyl quinoline-2-carboxylate

[KlementineJBS]

Link to HIRAC and original method.

KBS34 - Synthesis of methyl quinoline-2-carboxylate.docx

Reaction scheme

Outcome

462.2 mg (2.47 mmol, 82%)

[KlementineJBS]

1. Dissolved quinoline-2-carboxylic acid (522 mg, 3.01 mmol) in methanol (5 mL)
2. Added concentrated sulfuric acid (98%, 0.15 mL)
3. Left stirring at 65 C from 11.35 am

TLC at 4.30 pm indicated formation of product but SM was still present as indicated by positive staining with bromocresol green.

Turned up heat to 70 C as no condensation was visible and left overnight.

[KlementineJBS]

TLC at 9 am indicated that reaction was still not yet complete. Worked up anyway - not sure how sensitive the bromocresol is, and no UV showed up on the baseline for RM.

4. Neutralised to > pH 7 with NaHCO3 (~ 15 mL). Reaction grew cloudy white with precipitate.
5. Extracted with chloroform (4 x 5 mL)
6. Dried over mag sulphate and rotovapped down

Empty vial: 15.8551 Full vial: 16.3173 Mass: 462.2 mg (2.47 mmol, 82%)

Hard brittle solid, pale beige in colour.

[KlementineJBS]

NMR

1H NMR (300 MHz, Chloroform-d) δ 8.29 (dd, J = 8.5, 1.9 Hz, 2H), 8.18 (d, J = 8.5 Hz, 1H), 7.86 (dd, J = 8.2, 1.5 Hz, 1H), 7.77 (ddd, J = 8.4, 6.8, 1.5 Hz, 1H), 7.63 (ddd, J = 8.1, 6.9, 1.2 Hz, 1H), 4.07 (s, 3H).

KBS34-1.1.zip KBS34-1.pdf

[KlementineJBS]

LRMS

Peaks at 188.16 [M+H]+ and 210.12 [M+Na]+ indicate product.

KBS34-1.d.zip KBS34-1.pdf

[KlementineJBS]

Compound was re-dissolved by chloroform from NMR and rotovapped down - formed white crystalline solid.