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23rd January 2014 @ 11:46

Yield of 45%, though solvent (mainly IPA, NH3) leaked through seal. 

Repeat of CT 3-1 with a shorter time to see if there is a difference in yield/mixture of products. 4 hours was sufficient for all starting material to disappear, but a mix of products was obtained in CT 3-1. 

Reaction scheme


AEW 99-1 (0.100 g, 0.4 mmol), isopropanol (3 mL) and ammonia (6 mL) were added to a sealed tube, stirred and heated at 120 °C for 2 hours. The reaction mixture was cooled to rt and the solvent removed under vacuum. The crude product was purified by flash column chromatography over silica (95:4.5:0.5 DCM:MeOH:NH3) to yield the product as a yellow solid (41 mg, 0.18 mmol, 45%).

Note: Over half of the solvent had evaporated after 2 hours. Seal was not in great condition before the reaction (but worked for the last reaction), and seemed to be cracked upon inspection afterwards. 



1H NMR of crude product. Two products, the major product consistent with the desired product (CT 3-1. The other product could be the -OH substituted product (also replacing -Cl), as the reaction was concentrated in water due to a faulty seal. 

CT 3-2 crude proton.pdf

1H NMR of 3rd fraction. Chemical shifts correspond with the other major product (not the desired product), thought to possibly be the -OH substituted product (~18 mg). The fraction appears to be quite pure, so will further characterise the product to determine structure. 

CT 3-2 fraction 3 proton.pdf

1H NMR of 4th fraction. Chemical shifts correspond to the desired product (see previous CT 3-1) though with a small impurity. The fractions may require further drying, although the impurity is not a water signal. 

CT 3-2 fraction 4 proton.pdf


Crude TLC showed two spots, consistent with two products in the 1H spectrum. 

After column chromatography

The 'smear' in tubes 9-11 appears to be 2 spots, as separated in 12-13.

4 fractions collected, co-spotted with pure product from CT 3-1



CT 3-1 HIRAC.pdf

InChI strings




Attached Files
CT 3-1 HIRAC.pdf
CT 3-1 scheme.cdx
CT 3-1 scheme.png
CT 3-2 crude proton.pdf
CT 3-2
CT 3-2 fraction 3 proton.pdf
CT 3-2 fraction 4 proton.pdf
CT 3-2 fraction
CT 3-2 fraction
CT 3-2 column 1.JPG
CT 3-2 column 2.JPG
CT 3-2 column 3.JPG
CT 3-2 reference co-spot.JPG
Re: Synthesis of 6-Bromothieno[3,2-d]pyrimidin-4-amine (CT 3-2) by Matthew Todd
27th January 2014 @ 09:55
At the time of writing your reason for this experiment is "Repeat of CT 3-1 with a shorter time to see if there is a difference in yield." - what was the yield of 3-1 and why do you think shorter rxn time is the solution? Did you think that you had product decomposition?
Re: Synthesis of 6-Bromothieno[3,2-d]pyrimidin-4-amine (CT 3-2) by Carmen Tran
28th January 2014 @ 03:43
Info has been updated in the relevant posts, but yield of CT 3-1 was 33%, with complete disappearance of starting material and a mix of products (possibly the debrominated product). The shorter reaction time is to see if we can minimise these side reactions while achieving a similar (or better) yield.