If you had typed in "atropine" in TFSE over at Rhodium's, you would have been directed to the Alkaloid Extraction Document by Osmium.
https://www.thevespiary.org/rhodium/Rhodium/chemistry/alkastract.html
Many alkaloids can be isolated directly from the alkoholic extract by chromatographic methods. This is a separation which works well for tropane alkaloids (atropine, cocaine, scopolamine).Also, from
King's American Dispensatory. by Harvey Felter, and John Lloyd:An easy process for the preparation of Atropine is as follows: One pound of the dry leaves of belladonna are to be boiled in distilled water sufficient to cover them for 2 hours, and the decoction strained off through a coarse cloth into a large precipitating jar. The leaves are again boiled in a second water and the decoctions mixed, to which 2 drachms of strong sulphuric acid are now added; the vegetable albumen is precipitated, and the clear liquor is drawn off with a siphon to a filter. A clear, sherry-colored solution comes through, which is either decomposed by passing gaseous ammonia through it, or by adding commercial carbonate of ammonium. In either case the color becomes changed to black, and crystals of atropine are slowly formed. At the expiration of a day or so the supernatant liquor may be drawn off with a siphon, and the crystals
thrown on a filter to dry. To decolorize them, about 1 ounce of spirit of ammonia may be poured on the filter, which washes away most of the coloring matter, leaving the crystals moderately white. Purify by dissolving in boiling alcohol and recrystallizing.
You should also find this PDF helpful:
http://www.ams.usda.gov/nop/NationalList/
TAPReviews/Atropine.pdf
Basic Overview: Long preparation of tropinone; preparation of tropic acid; combination of tropinone and tropic acid yielding atropine. The process they suggest for preparing tropinone is exhaustive.
“ Although the individual steps in the synthesis generally give good to excellent yields, there are many of them which means that the overall yield becomes diminishingly small, of the order of 1%.” It would be a lot easier for you to prepare tropinone as detailed in
https://www.thevespiary.org/rhodium/Rhodium/chemistry/cocaine.synthesis.txt
“Take the total amount of succinaldehyde (obtained from 4
of the above syntheses combined) and without further treatment or purification (this had better be 15.5 g of succindialdehyde) put into an Erlenmeyer flask of 4-5 liters capacity. Add 21.6 g of methylamine hydrochloride, 46.7 g of acetonedicarboxylic acid, and enough water to make a total volume of 2 liters. Adjust the pH to 8-10 by slowly adding a saturated solution of disodium phosphate. The condensate of this reaction (allow to set for about 6 days) is extracted with ether, the ethereal solution is dried over sodium sulphate and distilled, the product coming over at 113 C at 25 mm of pressure is collected. Upon cooling, 14 g of tropinone crystallizes in the pure state.”
(See document for preparation of succinaldehyde via succinaldoxime)
One would then produce tropic acid from phenylacetic acid by means of a Grignard and formaldehyde.
Then heat the tropic acid with the tropinone in the presence of about 3% HCl (Fischer-Speier Esterification) to obtain atropine. Why one would go through all of that just for some atropine, I’ll never know; but that’s how you make it.