(1) Take 3500g of coconut oil and place it in an enamel container. Add 750g of sodium hydroxide and 250g of sulfuric acid respectively. After saponification and acidification, place it in a vacuum fractionation apparatus and fractionate it under reduced pressure at 150℃ and 120mmHg to obtain dodecanoic acid;
(2) Preparation of calcium salt
Take 1800g of sieved lime and add 2500ml of water to make a paste. Separately, heat 500g of dodecanoic acid in a 10,000ml porcelain bucket to completely dissolve it. Mix it evenly with 2500g of glacial acetic acid and pour it into the lime paste. Stir continuously to obtain calcium salt. Let it stand overnight (preparation of calcium salt);
(3) Preparation of mixed ketones:
Put the obtained calcium salt into a pyrolysis tank and heat it directly for 10 hours to obtain about 750ml of mixed ketones;
(4) Preparation of tridecone-2 (fractionation)
Take 1000ml of mixed ketones and pour it into a round-bottom flask. Add 2-3 glass beads to prevent boiling. Connect the fractionation apparatus and then heat (temperature controlled at 150℃, pressure controlled at 120mmHg) and distill under reduced pressure. Collect the fraction within this range and weigh it to obtain tridecanoyl-2;
(5) Preparation of sodium dodecanoyl acetaldehyde:
Take 200g of tridecanoyl-2, 750g of ethyl formate, and 1000ml of anhydrous benzene and mix them in a 5000ml Erlenmeyer flask. Then take 125g of metallic sodium, chop it, and add it to the mixture in portions. Shake it thoroughly. Cool the Erlenmeyer flask with ice water and keep the reaction solution at 25℃. Let it stand at room temperature to obtain sodium dodecanoyl acetaldehyde;
(6) Addition of sodium dodecanoyl acetaldehyde bisulfite
The above reactants were extracted with water four times: 2000 ml × 2, 1000 ml × 2. The four extracts were combined. Separately, 750 g of NaHSO3 was dissolved in 1500 ml of water and mixed with 250 ml of glacial acetic acid. The above water extract was added, and a large amount of white precipitate was immediately formed. The mixture was stirred evenly, allowed to stand, filtered, dried, and allowed to stand again. The precipitate was poured into a porcelain container and heated to boiling in a water bath with 8000 ml of 50% ethanol. After filtration, the filtrate was heated to boiling again in a water bath and allowed to stand overnight for recrystallization. The filtrate was then filtered to dryness, washed several times with about 1500 ml of diethyl ether, then washed with water, and then washed with diethyl ether until white. The filtrate was then dried at 80°C to obtain Sodium lauryl sulfoacetate.
