1017.     ---------------.  [Synthesis of Higher Members of the Aliphatic Series From Carbon Monoxide.]  Ber. Deut. Chem. Gesell., vol. 56B, 1923, pp. 2428-2443; Chem. Abs., vol. 18, 1924, p. 1379.

        Having found that formates could be made from CO and bases and that these formates could be converted by thermal decomposition into liquids like MeOH, Me₂CO, etc. (abs. 1013), Fischer and Tropsch, in an effort to obtain liquid fuels suitable for motors, directly in 1 operation, studied the action on water gas of various bases and salts, which under pressure with CO gave formates, spread on a number of carriers, but only when metals, such as Fe shavings, were used as the carrier were they successful.  The bases or the metals alone, German Patents 293, 787, 295, 208 and 295, 202, will not do.  The water gas, freed as completely as possible of S compounds, was passed under 150 atm. into the contact chamber, containing, for example, K₂CO₃ on Fe shavings, at 400°-450°, and the product was collected under pressure in a cold receiver.  This product generally separated into 2 layers, 1 vol. oil and 2 vol. of an aqueous solution, 20% of which consisted of aliphatic alcohols, aldehydes, ketones, and free fatty acids.  Of the oil, 41% boiled below 100°, 73% below 150°, 83% below 180°, and 88% below 200°; 1,450 gm. of the crude products, shaken with 5 N NaOH, and washed with H₂O, which dissolved about 10% of nonacid constituents, which on fractional distillation again gave a distillate only partly miscible with H₂O, yielded 943 gm. oil volatile with steam and 41.6 gm. residue; of the volatile portion, 40, 63, 77, 87, 92 and 96% boiled below 100°, 125°, 150°, 175°, 200° and 225°, respectively.  Among the acids in the aqueous and oily layers were identified HCO₂H (by reduction of HgCl₂), AcOH (anilide), EtCO₂H (basic Pb salt), and Me₂CHCO₂H (conversion into Me₂C(OH)CO₂H); the equivalent weights of the higher fractions indicated the presence of acids up to C₈H₁₆O₂.  The fraction of volatile oil boiling below 100° contained 7.2% aldehyde (calculated as PrCHO) and the fraction boiling above 100°, 25.9%; in the former were identified, by conversion into the acids, EtCHO, PrCHO, and Me₂CHCHO; no HCHO could be detected.  Me₂CO, MeCOEt, Et₂CO, and MeCOPr were isolated, the first as the oxime and semicarbazone, the others as the p-nitrophenylhydrazones.  MeOH was identified through its oxalate, EtOH through its acetate, and PrOH through its p-nitrobenzoate; the Ac number of the oil indicate the presence of about 50% alcohols, calculated as C₆H₁₁OH; its saponification value indicated a 4% content of ester, as AcOEt.  After treatment with NaHSO₃, which dissolved 25%, and repeated distillation from Na, the oil yielded 2.5% hydrocarbons C₁₀H₈, still containing 0.22% O.  Below are the % yields of products thus far identified:  Acids, 10 (HCO₂H 0.1, AcOH 2.3, EtCO₂H 2.1, Me₂CHCO₂H 1.0, higher acids 4.5); H₂O-soluble alcohols; aldehydes and ketones, 29 (MeOH 1.5, EtOH 14.5, Me₂CO 5.2); oil partly miscible with H₂O, 11; oil volatile with steam 48% (higher alcohols up to C₉ 15.0, esters 2.0 hydrocarbons 1.3); oil not volatile with steam, 2%.  The HO-soluble product is designated pyrosynthol, the volatile oil, synthol (=synthetic oil).  The latter is converted by heating under pressure into synthin (=synthetic benzine); 25 gm. heated in a 250 cc. autoclave filled with N₂ for 1 hr. at 420° gave 2,250 cc. gas (14.5% CO₂, 22.7% hydrocarbons absorbed by fuming H₂SO₄, 0.7% O₂, 14.6% CO, 9.6% H₂, 21.8% CH₄ hydrocarbons, 16.1% N₂), 17.5 cc. of the dark red-brown oil and 3.5 cc. of an aqueous layer.  Of the oil, 4, 10, 17, 22, 35, 48, 57, 65, 74, 78, and 84% boiling below 50°, 75°, 100°, 125°, 150°, 175°, 200°, 225°, 275°, and 300°, respectively.  The fraction boiling below 100° had a benzinelike odor and only slightly colored concentrated H₂SO₄.  Of the fraction boiling above 100°, 50% dissolved in concentrated H₂SO₄.  The insoluble portion, washed with H₂O and Na₂CO₃ and distilled with steam, had a pronounced petroleum odor and 24, 44, 27, and 5% boiled at 120°-150°, 150°-200°, 200°-270°, and above 270°, respectively; it consisted of hydrocarbons ranging from C 84.48, H 15.14%, d.²⁰₄ 0.762 for the 75°-100° fraction to C 88.43, H 12.05%, d.²⁰₄ 0.874 for the 200°-270° fraction.  The H₂SO₄ solution on dilution with H₂O gave an oil 33.54, and 13% of which boiled at 100°-175°, 175°-235°, and above 235°, respectively; the 175°-235° fraction contained 79.05% C and 11.20% H.  Outside of Fe, only those of the non-noble metals that are known to be H carriers, Ni, Co, and possibly Mn, will effect the above reaction; a base or salt of a base with a weak acid is also essential, and apparently the oil formation proceeds more satisfactorily the stronger the base.  The various possible mechanisms of the reaction are briefly discussed.