4,7-Methano-3a,4,5,6,7,7a-hexahydroinden-6-yl acetate

Liquid

B. Synthesis of TCDA. Dicyclopentadiene (DCPD, 1048 g, 86percent pure) is added dropwise at 115-120° C. to the mixture obtained in Step A over 4 h. The reaction mixture stirs for an additional 2 h at 130° C. and is then cooled to 40° C. Crude material (1564 g) is distilled with aqueous sodium hydroxide (1.0 g of 50percent solution) added to the distillation pot. Acetic acid (100 g) is first stripped off at 150 to 1 torr (i.e., 150 to 1 mm Hg). The distillation column is then set for 12 h of total reflux at 1 torr to remove residual acetic acid. Distillation of the remaining material at 1 torr provides commercial-grade TCDA (911 g, 68percent based on DCPD). Major isomer by GC: 92.9percent; Isomer A: 1.8percent; Isomer B: 4.2percent; Isomer C, 0.55percent.Targeted ranges for TCDA: Major isomer: >90percent; Isomer A: <2percent; Isomer B: 1-6percent; Isomer C: <3percent.B. Synthesis of TCDA. DCPD (1048 g, 86percent pure) is added dropwise at 115-120° C. to the mixture obtained in Step A over 4 h. The reaction mixture is stirred for an additional 2 h at 130° C. and is then cooled to 40° C. Crude material (1564 g) is distilled with 0.86 g of 50percent aqueous NaOH added to the distillation pot. Acetic acid (100 g) is removed at 150-1 torr. The distillation column is then set for 12 h of total reflux at 1 torr to remove residual acetic acid. Distillation of remaining material at 1 torr provides commercial-grade TCDA (947 g, 71percent based on DCPD). Major isomer by GC: 92.9percent; Isomer A: 1.6percent; Isomer B: 4.3percent; Isomer C, 0.5percent.COMPARATIVE EXAMPLE 3Distillation without Neutralization of Triflic AcidThe procedure of is repeated, except that no NaOH solution is added to the distillation pot in Step B. Distillation of the crude reaction mixture (1554 g) provides acetic acid (145 g) and TCDA (670 g, only 47percent based on DCPD) that does not meet isomer ratio specifications required for commercial product. Major isomer by GC: 93.1percent; Isomer A: 2.5percent (too high); Isomer B: 3.0percent; Isomer C, 0.67percent.B. Synthesis of TCDA. DCPD (1048 g, 86percent pure) is added dropwise at 115-140° C. to the mixture obtained in Step A over 3 h. The reaction mixture stirs for an additional 3 h at 140° C. and is then cooled to 40° C. Crude material is distilled with aqueous sodium hydroxide (7.0 g of 50percent solution) added to the distillation pot. Acetic acid is first stripped off at 20 torr. The distillation column is then set for 20 h of total reflux at 1 torr to remove residual acetic acid. The remaining material is distilled at 1 torr. The resulting TCDA product (708 g, 73percent based on DCPD) meets target specifications regarding isomer content (major isomer by GC: 92.0percent; Isomer A: 1.2percent; Isomer B: 5.5percent; Isomer C, 1.1percent). However, the product fails the odor specification because it has a pungent, acidic odor.COMPARATIVE EXAMPLE 7BF3.2H2O CatalystThe procedure of Comparative Example 6 is generally followed, except that 31.0 g of 50percent aqueous sodium hydroxide solution (not 7.0 g) is added to the distillation pot in Part B. The resulting TCDA product (441 g, 34percent based on DCPD) meets target specifications regarding isomer content (major isomer by GC: 91.7percent; Isomer A: 1.4percent; Isomer B: 5.6percent; Isomer C, 1.1percent). However, the product fails the odor specification because it has a pungent, acidic odor.Dicyclopentadiene (DCPD, 1048 g, purity 86percent) is added dropwise at 90-110° C. to a stirred mixture of glacial acetic acid (420 g) and triflic acid (1.18 g) over 5.7 h. The reaction mixture is then stirred for 2.5 h at 120° C. Brine (98 g, d420 1.202), water (49 g), and 50percent aq. NaOH solution (61 g) are added at 50° C., and the mixture stirs for 0.5 h. After the layers settle, the organic phase is isolated and washed with brine (2.x.125 g). Distillation of crude material (1409 g) at 1 torr provides commercial grade TCDA (888 g, 67percent based on DCPD). Major isomer by gas chromatography (GC): 92.4percent; Isomer A: 1.6percent; Isomer B: 4.3percent; Isomer C: 0.5percent.Targeted ranges: Major isomer: >90percent; Isomer A: <2percent; Isomer B: 1-6percent; Isomer C: <3percent.; Step A. Hydrolysis of acetic anhydride. A by-product stream containing about 80 wt. percent of acetic acid, acetic anhydride (about 13 wt. percent), alpha-pinene, limonene, acetate esters, and other impurities, is combined with enough water (12.3 mL) to hydrolyze the acetic anhydride. Triflic acid (1.36 g) is added, and the mixture is heated with stirring to 110° C. and kept at this temperature for 30 min. GC of the resulting dark brown mixture indicates the absence of acetic anhydride, about 90 wt. percent of acetic acid, and the balance of a complex mixture of organic compounds.Step B. Synthesis of TCDA. DCPD (1048 g, 86percent pure) is added dropwise at 110-120° C. to the mixture obtained in Step A over 5.7 hrs. The reaction mixture is stirred for an additional 2.5 h at 120° C. and is then cooled to 40° C. Brine (98 g, d420 1.20), water (49 g), and 50percent aqueous NaOH (61 g) are added at 50° C. and the mixture stirs for 30 min. The layers are separated and the organic phase is washed with brine (2.x.125 g). Crude material (1423 g) is distilled at 1 torr to provide commercial grade TCDA (925 g, 69percent based on DCPD).Example 3 demonstrates that fragrance-quality TCDA can be made from crude, recycled acetic acid and technical grade DCPD.; A mixture of DCPD (1048 g, 87-88percent), triflic acid (1.19 g), and glacial acetic acid (420 g) is heated with stirring to 130° C. over 55 min. The mixture is kept at 130-135° C. for an additional 2.4 h, then cooled to 40° C. Brine (104 g, d420 1.20), water (52 g), and 50percent aqueous NaOH (66 g) are added at 50° C., and the mixture stirs for 30 min. The phases are separated, and the organic layer is washed with brine (2.x.125 g). Crude material (1284 g) is distilled at 1 torr to provide commercial grade TCDA (690 g, 51percent based on DCPD).Examples 1 and 4 show that the yield of commercially acceptable TCDA is enhanced by gradual addition of DCPD to a mixture of acetic acid and triflic acid.Dicyclopentadiene (DCPD, 1048 g, purity: 86percent) is added dropwise at 90-140° C. to a stirred mixture of glacial acetic acid (420 g) and boron trifluoride:acetic acid, 1:2 adduct (15.9 g) over 3.25 h. The reaction mixture is then stirred for 0.75 h at 140° C. Brine (100 g), water (50 g), and 50percent aq. NaOH solution (68 g) are added at 50° C., and the mixture stirs for 0.5 h. After the layers settle, the organic phase is isolated and washed with brine (2.x.125 g). Distillation of crude material (1415 g) at 1 torr provides TCDA (786 g, 60percent based on DCPD) that is dissimilar to commercial TCDA in terms of isomer content. Major isomer: 90.5percent; Isomer A: 4.1percent; Isomer B: 3.7percent; Isomer C: 1.4percent.shows that the inventive process provides a TCDA product that falls within the targeted isomer requirements. When the procedure is modified (Comparative Example 2), too little of the major isomer is made, and too much of Isomer A is produced. An additional comparative experiment demonstrated that commercially acceptable TCDA can be made with the BF3 catalyst by using a large excess of acetic acid and DCPD having a purity of 93percent.

Used in food, daily fragrance

Odor agents

Air care products

1,000,000 - 10,000,000 lb

Molecular Weight:192.25
XLogP3:2.2
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:2
Exact Mass:192.115029749
Monoisotopic Mass:192.115029749
Topological Polar Surface Area:26.3
Heavy Atom Count:14
Complexity:295
Undefined Atom Stereocenter Count:5
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes