KBS13-2 - Deprotection of bis-adamantane cyclam

[KlementineJBS]

Deprotection of bis-adamantane cyclam

Link to HIRAC and original method.

Outcome

213 mg (0.303 mmol), 124%

Reaction Scheme

MW SM = 831
MW product = 703.92

Method

KBS12-1 (203 mg, 0.244 mmol) was dissolved in dioxane (3 mL) and HCl (4 M in dioxane, 0.5 mL) was added. The reaction was stirred at room temperature for 45 minutes before being concentrated under reduced pressure. The mixture was suspended in methanol and concentrated under reduced pressure again to yield a pale green-blue powder. The powder was passed through a column containing Ambersep to convert it into the free base form and purified using automated column chromatography (?).

TLC Conditions

CHCl3:MeOH:NH4OH = 9:90:1, permanganate

Characterisation

NMR

H NMR, 300 MHz, CDCl3

KBS13-2 free base.pdf

*Peaks at 7.56 (s, 2H), 3.74 (s, 4H), 1.70 - 2.72 (indistinct, 52H)

Mass Spec

KBS13-2 FB.pdf

LRMS

20210601_KBS13-2 F1-2.pdf
20210601_KBS13-2 FB.pdf
20210601_KBS13-2 F3-17.pdf

20210601_KBS13-2 FB.d.zip
20210601_KBS13-2 F3-17.d.zip
20210601_KBS13-2 F1-2.d.zip

KBS13-2 FB F1-2.zip

20210603_KBS13-2 FB F3-6.d.zip

20210603_KBS13-2 FB F7-10.d.zip

KBS13-2 FB F1-2.pdf

KBS13-2 FB F7-10.pdf

KBS13-2 FB F3-6.pdf

[KlementineJBS]

To consider

[KlementineJBS]

24.05.21

• 203 mg KBS12 in 3 mL dioxane
• added 0.5mL HCl in dioxane at 4pm
• not under nitrogen

• formed a precipitate after ~30 minutes
• TLC'd at 4.45 pm in chloroform:MeOH:ammonia + permanganate stain

• rotvapped (in toxics)

[KlementineJBS]

25.05.21

• transferred white-yellow solid from flask to vial with MeOH and rotvapped
• upon immersion in rotvap bath, MeOH turned light blue while precipitate remained suspended
• formed a pale green-blue powdery solid
• tried EtOAc instead - also not very soluble
• weight of crude product = 213 mg

[KlementineJBS]

26.05.21

• converted one portion (105 mg, 0.149 mmol) to free base using Ambersep
• yield = 91 mg (0.144 mmol, 97%)
• purple colour

NMR

KBS13-2 free base.pdf

inconclusive

[KlementineJBS]

27.05.21

• columned remaining KBS12 using reverse phase
• two products: F1-2 (99 mg - purpley blue in colour) and F3-17 (42 mg - yellowish)

NMR

KBS13-2 F1-2.pdf
KBS13-2 F3-17.pdf

• inconclusive