I have found a wonderfully elegant route to make a compound a friend asked for. The problem is that it takes 2500mL of methanol to dissolve 250g of the main precursor. The paper simply states that the methanol is distilled off which is going to be SLOW. Evidently the product is also soluble in methanol AND DCM. AFAIK the addition salt of the product is also soluble in methanol but I'm not sure if it's soluble in DCM (likely not). I wondered if anyone knew of a cunning method of producing an insoluble derivative.
Much as I hate crashing stuff out because it's such a waste so I have toyed with the idea of freezing out the product. The reaction is run at 30°C but before NaBH4, it's chilled to 0°C. Now the paper I based this on used methylamine hydrochloride (freebased by KOH that also removes water from the system) but in my case, BP is >30°C. The NaBH4 is added in 3 lots so I am wondering if that lower temperature is just to ensure that no amine escapes.
I wish I could be more specific but when the time comes, you will be the first to know. All I can tell you that it was the result of patent mining on a massive scale. This took >150 searches. AFAIK the product is legal everywhere.
Much as I hate crashing stuff out because it's such a waste so I have toyed with the idea of freezing out the product. The reaction is run at 30°C but before NaBH4, it's chilled to 0°C. Now the paper I based this on used methylamine hydrochloride (freebased by KOH that also removes water from the system) but in my case, BP is >30°C. The NaBH4 is added in 3 lots so I am wondering if that lower temperature is just to ensure that no amine escapes.
I wish I could be more specific but when the time comes, you will be the first to know. All I can tell you that it was the result of patent mining on a massive scale. This took >150 searches. AFAIK the product is legal everywhere.