MJE9-1- Carbamate cleavage

[memm0740]

HIRAC- MJE9.docx

[memm0740]

11/07/23 12pm

Method 9-1

1. Added 1C, MeOH, NaOH as on HIRAC. Reflux started at 12:50pm.

4pm

• dissolved 1C, RM in MeOH
• TLC MeOH 9%/DCM90%/NH41%- RM has 3 spots

5:30pm

• TLC MeOH 9%/DCM90%/NH41%- 3 spots for RM

  

• therefore left reaction overnight

12/07/23 9am

• MS to check reaction progress 230712_MJE9-1.crude1.pdf 230712_MJE9-1.crude1.d.zip Note- large peak in negative ions at 210- lost proton possibly from free amine, most likely due to NaOH. So reaction worked, can work up.

• TLC- no strong thiourea spot, RM has 3 slight spots

  

1:10pm

2. Work up
   • rotovap off MeOH
   • added RM, EtOAc and brine to sep funnel
   • washed organic layer with 4x4mL brine
   • collected organic layers and dried using MgSO4
   • filtered out MgSO4

13/07/23 12:30pm

• rotovapped EtOAc off- vial with product (clear yellow colour) concentrated

• MS 230713_MJE9-1.crude2.pdf 20230713_MJE9-1.crude2.d.zip

3pm TLC for column conditions- MeOH 9%/DCM90%/NH41%

• left on high vac overnight.

14/07/23 9am -NMR 9-1 after work up and overnight vacuum MJE9-1.pdf MJE9-1.dried_1.zip Note- lot of water and DMSO- not sure where DMSO came from (REDO)

3pm

• need to purify- column conditions

• TLC MeOH 9%/DCM90%/NH41%- Rf of largest spot 0.375

• TLC MeOH 5%/DCM 45%- Rf=

  

• vial +product= 16.0358g (vial= 16.0358g)

• dry loaded (dissolve in acetone, RV)

5pm

• column done under MeOH 5-10%/DCM 45%-90%- no significant peaks noticed
• TLC every fraction

17/07/23 11:30am

• MS Fraction 12 230717_MJE9-1.f12.pdf 230717_MJE9-1.f12.d.zip

Fraction 19 230717_MJE9-1.f19.pdf 230717_MJE9-1.f19.d.zip

• combine fractions 12-19 (also shown on TLC)
• RV off MeOH/DCM
• transfer to vial (vial= 15.971g)
• left to dry in dessicator

18/07/23 9am

• put on high vacuum immediately
• vial + product= 15.9801g =9.1mg product yield= n(carbamate SM)= 3.72mmol n(product)= 0.0091/211= 0.0000431mol= 0.0431mmol %yield= 0.0431/3.72 *100= 1.15=1%

12pm

• NMR MJE9-1. column.pdf MJE9-1.column_1.zip

Note- hard to confirm structure by NMR

[memm0740]

03/08/23 10pm

Method 9-2

1. Added 1C (0.104g), MeOH (1.77mL) slurry.
2. Added 2M NaOH (1.77mL) as on HIRAC. Reflux started at 10:25am.

2:30pm

• dissolved partially 1C and RM in MeOH
• TLC MeOH 9%, DCM 90%, NH1%- still SM present (see below in 04/08)

4:45pm

• MS (messy) 230803_MJE9-2.crude 1.pdf 230803_MJE9-2.crude1.zip

04/08/23 10am

• MS (clear 210-1 peak) 230804_MJE9-2.crude2.pdf 230804_MJE9-2.crude2.d.zip

11:30am

• TLC- SM still present

07/08/23 9am

• turned back on
• TLC 9%MeOH/90% DCM/1%NH4 TLC5%MeOH/95% DCM- reaction most likely done

5pm MS (large 210-1 peak) 230807_MJE9-2.crude3.pdf 230807_MJE9-2.crude3.d.zip

• reaction ready to work up

08/08/23 12:30pm TLC 9% MeOH- no starting material spots in RM

4pm

• Work up
• RV methanol off
• added 4mL brine and EtOAc but no separation in separating funnel, therefore need to further RV potrentially MeOH, EtOAc, water if possible

09/08/23 9am

• RV
• added 10mL water to dissolve salt, 10mL EtOAc, extract x3 4mL brine
• dry with MgSO4
• filter off MgSO4
• RV organic

3:30pm

• TLC organic for column
• 7% MeOH/ 92.5% DCM seems best

14/08/23 12pm

• vial + product= 16.1625g

3:30pm

• column in 7.5% MeOH/DCM and increased MeOH to 5%.

15/08/23 9am

• combined fractions for second spot
• NMR that spot 9-2. spot 2.pdf MJE9-2.c_1.zip Note- NMR has potential but too high peaks from methanol, water and acetone at 2.13.

16/08/23 9-10am

• MS of spot (corrupted pdf, but zip available) 230816_MJE9-2.c.d.zip

Note- high in 211

• %yield= 0.0000165/0.0003866 x 100= 4.26%

28/08/23 2pm

• flushed column with 100% MeOH
• tried to TLC 3 different peaks but not showing up

[memm0740]

29/08/23 10am

Method 9-3

1. Added 1C (0.105g), MeOH (1.77mL) slurry. Added 2M NaOH (1.77mL) as on HIRAC. Reflux started at 10:52am.
   • TLC 7.5%
   • left overnight

30/08/23 11am

• TLC

01/09/23 9:30am

• TLC 5.6% MeOH, 0.625% NH4OH, 94.4% DCM - sloped to RHS
• TLC 2.8% MeOH, 0.312% NH4OH, 97.2% DCM- minimal SM, possible product spot

10:45am MS

• files not found but 211 there

-NMR MJE9-3crude1_1.zip MJE9-3.crude1.pdf

• after meeting decided to add water to hope hydroxide ion would attack to form intermediate and allow ester to fall off. As what might be happening is methoxide anion from methanol forming intermediate and itself falling off generating SM again.

04/09/23 11am

• TLC 2.8% MeOH, 0.312% NH4OH, 97.2% DCM- spots didn't leave base

• 9% MeOH, 90% DCM, 1% NH4- very streaky but possibly no SM

  

• NMR- after looking at starting material seems there is thiourea still present shown by peaks at 2.5 and 3.7 MJE4a-4.dry.pdf mje4A-4.DRY_1 (1).zip

• MS

  

3pm

• trying to figure out if thiourea present in 4a-4, because it is the S methyl could be interfering with methyl peak in 9-3 product.

4pm

• work up at TLC shows no SM

• RV off MeOH

• liq-liq with 6mL each of EtOAc/ brine

• dried organic layer with MgSO4- 26.829 (flask and organic dried)

• RV organic

• MS org- 211

• MS aq- no 211

• CNMR of 4a-4

• CNMR 9-3

05/09/23 9am

• measured 15mL aqueous total

• transferred organic to vial, after rotor vap- 0.0162g (16.2mg)

• decided to rinse MgSO4 with 5mL MeOH

07/09/23

• RV water from aqueous
• add 5mL DCM and RV
• failed C NMR of 4a-4, and 9-3- (someone refilled deuterated DMSO with non-deuterated)

08/09/23

• RV water from aqueous

• add 5mL DCM and RV

• NMR of 9-3aq MJE9-3.aq.pdf MJE9-3.aqm_1.zip

• possibly run NMR with water suppression???

• most likely not product as don't match peaks

• rinsed 4a-4 with diethyl ether to attempt to rid peak at 3.68 (integrates to 1.94) MJE4a-4.dry.pdf mje4A-4.DRY_1 (1).zip

11/09/23 9am

• new amount of 4a-4 rinsed= 379mg
• NMR of 4a-4 after rinsing with diethyl ether MJE4a-4.ether rinse.pdf MJE4a-4ether rinse.zip Note- didn't get rid of peak

3pm

• set up 9-4 and 9-5
• 2D NMR of 4a-4

[memm0740]

Method 9-4

11/09/23 3pm

1. Added 1c (64mg), NaOH 2M (1mL), EtOH (1mL). Did not dissolve. 12/09/23 9am
   • RM looks completely dissolved
   • TLC 7.5% MeOH- slight SM

• TLC 9%MeOH/DCM/1%NH4- no SM

13/09/23 11am

2. Work up- RV off EtOH
   • RM looks completely dissolved
   • during RV RM went from pale brown to bright red

2pm

• NMR of crude RM 9-4 13-09.pdf MJE9-4_1.zip Note- ethanol interfering at 1.19

• NMR after RV 9-4 RV.pdf MJE9-4.RV_1.zip Note- strong MeOH peak

3:45pm

• added 1mL DCM, then RV 9-4 DCM RV.pdf MJE9-4.DCM_1.zip Note- no more methyl or unknown peak nearby. Higher DMSO peak at 2.5 than water at 3.36. Due to pretty sure just water and DMSO can ignore this.

15/09/23 10am

• CNMR, HSQC
• mass spec

18/09/23 3pm

2. Continue work up- triturate with EtOAc
   • final mass 40mg
   • %yield= 0.0001905/0.000237 x 100= 80%

• Liquid-liquid extraction with NaOH remaining in flask to see how much product could be extracted - added EtOAc (more) and water
• organic layer pipetted off and RV- mass 11.9mg

[memm0740]

Method 9-5

11/09/23 3pm

• added 1c (64mg), NaOH 2M (1mL), MeOH (1mL). Did not dissolve.

12/09/23 9am

• RM looks completely dissolved
• TLC 7.5% MeOH- almost no SM

• TLC 9%MeOH/DCM/1%NH4- no SM

13/09/23 9:30am

• heat RM further at 115C to see if carbamate affected by heat.

• NMR before heating 9-5 13-09.pdf MJE9-5_1 (1).zip Note- MeOH peak very strong

• NMR after RV 9-5 RV.pdf MJE9-5.RV_1 (1).zip Note- rMeOH peak at 3.16

3:45pm

• added 1mL DCM, then RV 9-5 DCM RV.pdf MJE9-5.DCM_1 (1).zip Note- no more methyl and other peak. Higher water peak at 3.39 compared to DMSO 2.5

15/09/23 10am

• CNMR, HSQC
• mass spec

18/09/23 3pm

2. Continue work up- triturate with EtOAc
   • final mass 36.1mg
   • %yield= 0.000171/0.000237 x 100= 72%

• Liquid-liquid extraction with NaOH remaining in flask to see how much product could be extracted - added EtOAc (more) and water
• organic layer pipetted off and RV- mass 12mg