Objective

To determine the solubility of boc-glycine in 2-propanol, benzene.

Procedure

Solutions of boc-glycine were prepared in 2-propanol and benzene in separate vials, by dissolving excess of solute in them.These solutions were left in a water-glycol bath at 40C for 1h, then they were left for the next 20h at 25C. The supernatants were then placed in clean and dry NMR tubes containing CDCl3 (700uL).The HNMR was obtained and the concentration of the saturated solutions were measured by SAMS method.

Discussion

For the solubility of boc-glycine in 2-propanol, mean is 3.625M at 25C, and standard deviation is 0.064
For the solubility of boc-glycine in benzene, mean is 0.255M at 25C, and standard deviation is 0.049
[You can also use the Google Spreadsheet built-in functions for average and stdev - I added these to the spreadsheet JCB][ok- Hai]

Results

Spreadsheet ONSCExp143-1


Conclusion

Solubility of boc-glycine in 2-propanol has been determined to be 3.625M at 25C - link
Solubility of boc-glycine in benzene has been determined to be 0.255M at 25C- link

Log

2009-10-30
12:30 Turned-on the "Lauda heating/cooling" device and set the temperature of the water/glycol to 40C.
13:00 Placed a small amount of boc-glycine into four small (half dram) vials, labeled 143-1, 143-2, 143-3 and 143-4. Then, used pipette to put few drops (like 5 or 6) of isopropanol into each of vial 143-1 and 143-2 and benzene into each of vial 143-3 and 143-4. vortexed each of them for a few seconds. The vials were parafilmed.
13:05 Put all vials into hot bath. Temperature was 40.5C. Set the temperature to 40C
13:50 At this time, all solid in vials 2 disappeared entirely while other still remained solid. Adjusted temperature down to 25C.
14:20 Temperature was 25C
14:40 Turned off the hot bath, and took all vials out.
14:45 Prepared 4 medium vials (1 dram) with 1000ul solution of CDCl3 in each of them by micro-pipette. Label them 1-4.
15:00 Centrifuged 143-1, 143-2, 143-3 and 143-4 (the ones with boc-glycine and solvent).
15:10 After centrifuging, decanted the clear supernatant into one draom vials containing CDCl3, labeled 1-4. Supernatant from 143-1 was decanted in to vial 1, supernatant from 143-2 in to vial 2, supernatant from 143-3 in to vial 3 and supernatant from 143-4 in to the vial labeled vial 4. The resulting solutions are now called ONSCExp143-1, ONSCExp143-2, ONSCExp143-3 and ONSCExp143-4, corresponding to initial sample IDs.
15:15 Pipetted out 700ul of the CDCl3/sample solutions in to four clean/dry NMR tubes. Labeled the NMR tubes same as the solution contained in them; ONSCExp143-1, ONSCExp143-2, ONSCExp143-3 and ONSCExp143-4.
15:20 Parafilmed all MNR tubes. Put them in a refrigerator.
19:00 Obtained HNMR of the solutions ONSCExp143-1, ONSCExp143-2, ONSCExp143-3 and ONSCExp143-4.